Vibration actuator, moving object having vibration actuator, moving object control system, and vacuum device

Abstract

The invention provides a vibration actuator, a moving object having the vibration actuator, a moving object control system, and a vacuum apparatus. A vibration actuator capable of improving wear resistance to achieve stable driving in a vacuum environment such as an outer space or a vacuum device. There is provided a vibration actuator including: a vibration member having a rectangular elastic member and an electromechanical energy conversion element; and a contact member in contact with the elastic member, in which the contact member and the vibrating member move relative to each other by vibration of the vibrating member, in which a flat portion and a protruding portion having a top portion and a wall portion are integrally formed on the elastic member, and each edge or the entire circumference of the top portion is supported by the wall portion, wherein the top portion is provided with a friction member different from the elastic member so as to be in contact with the contact member, where the friction member is a sphere or a cylinder, and where the friction member is supported by an inclined surface formed on the top portion.

Description

Technical Field

[0001] The present disclosure relates to a vibration actuator and a moving object having the vibration actuator. Background Art

[0002] Due to its slow speed, high thrust and other characteristics, the vibration actuator has been used as an automatic focus drive actuator for the photographic lens of a single-lens reflex camera. In recent years, the application of the vibration actuator in devices used in abnormal situations is also expected. Examples of applications include artificial satellites used in outer space and vacuum devices for production and analysis. These devices require actuator operation in a vacuum under abnormal conditions.

[0003] Japanese Patent No. 6938218 discusses a linear vibration actuator, which includes a vibration member formed by a rectangular elastic member and two different protrusions on the surface of the elastic member. A stainless steel sintered body impregnated with resin is arranged at the front end of each protrusion as a friction member. Through the vibration actuator, the contact member is in pressure contact with the front end of the protrusion, and a predetermined alternating current (AC) voltage is applied to the electromechanical energy conversion element to activate two different out-of-plane bending vibration modes. The activated vibration produces an elliptical motion at the front end of the protrusion, and the elliptical motion and friction cause relative movement between the vibration member and the contact member.

[0004] In a vacuum environment such as outer space or a vacuum device, the vibration actuator discussed in Japanese Patent No. 6938218 provides a significantly low thermal diffusion of the friction heat occurring on the friction plane between the vibration member and the contact member to the vacuum, so that the friction heat is retained. In addition, in a vacuum where there is almost no oxygen and moisture, no metal oxide layer is formed on the above-mentioned friction surface as a protective layer. This may cause adhesion to the friction plane. Therefore, a large amount of wear occurs on the friction surface of the vibration member, thereby reducing the friction characteristics, which may reduce the driving performance. Summary of the invention

[0005] The present disclosure aims to provide a vibration actuator having sufficient wear resistance so that stable driving can be achieved even in a vacuum environment such as outer space or a vacuum apparatus.

[0006] According to some embodiments, a vibration actuator is provided, which includes a vibration member having a rectangular elastic member and an electromechanical energy conversion element; and a contact member, which is in contact with the elastic member, wherein the contact member and the vibration member move relative to each other through the vibration of the vibration member, wherein a flat portion and a raised portion are formed on the elastic member, the raised portion having a top and a wall portion, and each edge or the entire circumference of the top is supported by the wall portion, wherein the top is provided with a friction member different from the elastic member to contact the contact member, wherein the friction member is a sphere or a cylinder, and wherein the friction member is supported by an inclined surface formed on the top.

[0007] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view showing an overall configuration of a vibration actuator according to a first exemplary embodiment of the present disclosure.

[0009] Figure 2 It is shown Figure 1 Exploded perspective view of the vibration actuator.

[0010] Figure 3 It is shown Figure 1 A three-dimensional diagram of the structure of the vibration component and the holding component.

[0011] Figure 4 It is shown Figure 3 An exploded perspective view of the vibrating component and the holding component.

[0012] Figure 5 is shown for activation Figure 1 A three-dimensional diagram of the vibration mode of the vibration component of the vibration actuator.

[0013] Figure 6 It is shown Figure 3 A cross-sectional view of the vibrating component in FIG.

[0014] Figure 7 It is shown Figure 3 A cross-sectional view of a portion of a vibrating component in FIG.

[0015] Figure 8 It is shown Figure 3 An exploded cross-sectional view of a portion of a vibrating component in FIG.

[0016] Fig. 9 It is shown Figure 3 Another exploded cross-sectional view of a portion of the vibrating member in FIG.

[0017] Fig.10is a cross-sectional view showing a portion of a first modification example of the vibration member according to the first exemplary embodiment.

[0018] Fig.11 is a cross-sectional view showing a part of a second modification example of the vibration member according to the first exemplary embodiment.

[0019] Fig.12 is a cross-sectional view showing a part of a third modification example of the vibration member according to the first exemplary embodiment.

[0020] Fig.13 is a perspective view showing a fourth modification example of the vibration member according to the first exemplary embodiment.

[0021] Fig.14 It is shown Fig.13 A cross-sectional view of a portion of a vibrating component in FIG.

[0022] Fig.15 It is shown Fig.13 Another cross-sectional view of a portion of a vibrating member in FIG.

[0023] Fig.16 is a schematic diagram showing a moving object having a body with a vibration actuator installed.

[0024] Fig.17 is a schematic diagram of a vacuum device equipped with a vibration actuator. DETAILED DESCRIPTION

[0025] Various exemplary embodiments, features, and aspects of the disclosure will be described in detail below with reference to the drawings.

[0026] “Vacuum” means low vacuum (lower than atmospheric pressure, equal to or higher than 100 Pascals (Pa)), medium vacuum, high vacuum, ultra-high vacuum or very high vacuum (lower than 1×10 -9 The shapes of the sphere and the cylinder include not only a perfect sphere and a circle, but also an ellipsoid close to a sphere and a cylinder with an elliptical cross section, which does not depart from the spirit and scope of the present disclosure.

[0027] Figure 1 is a perspective view showing an overall configuration of a vibration actuator 100 according to a first exemplary embodiment of the present disclosure. Figure 2 It is shown Figure 1 Exploded perspective view of the vibration actuator 100 in FIG. The moving direction of the contact member 9 is the X direction, the pressing direction is the Z direction, and the direction perpendicular to the X direction and the Z direction is the Y direction.

[0028] Figure 3 It is schematically shown Figure 1A three-dimensional diagram of the structure of the vibration component 2 and the holding component 6. Figure 4 It is shown Figure 3 Exploded perspective view of the vibration member 2 and the holding member 6. Figure 3 and Figure 4 , the flexible printed circuit board 5 is not shown.

[0029] The vibration actuator 100 includes a vibration member 2, 102 having an electromechanical energy conversion element 4, 104 and an elastic member 3, 103. The vibration member 2 held by the holding member 6 contacts the contact member 9. The vibration member 2 and the contact member 9 are configured to be relatively movable by vibration generated by the vibration member 2.

[0030] As a specific example of the construction, the vibration actuator 100 includes a contact member 9 that is in pressure contact with the elastic member 3 and a retaining member 6 having two different protrusions 61 (61-1 and 61-2), which serve as contact portions that contact a node on the side opposite to the side facing the contact member 9.

[0031] The vibration member 2 includes an elastic member 3, two different friction members 13 (13-1 and 13-2) and an electromechanical energy conversion element 4, and is powered from a power source (not shown) via a flexible printed circuit board 5. The electromechanical energy conversion element 4 is bonded to one main surface ( Figure 3 The electromechanical energy conversion element 4 is provided with a flexible printed circuit board 5 on the side opposite to the facing surface between the electromechanical energy conversion element 4 and the elastic member 3. The flexible printed circuit board 5 and the electromechanical energy conversion element 4 are electrically connected to each other.

[0032] The elastic member 3 is provided with two different protrusions 31 (31-1 and 31-2) on the side opposite to the facing surface between the elastic member 3 and the electromechanical energy conversion element 4. Each of the protrusions 31 has a wall portion backed up by the flat portion of the elastic member 3 and a top portion supported by the wall portion. The top portion (parietal portion) has edges and is supported by the wall portion on each edge or the entire circumference, thereby providing a strong structure against pressure in the Z direction. The following example is based on a structure in which the top portion is supported by the wall portion on the entire circumference.

[0033] The tops of the two protrusions 31 are provided with friction members 13 (13-1 and 13-2) as different members. Figure 3 Two protrusions 31 ( 31 - 1 and 31 - 2 ) are shown, but the relative movement between the vibration member 2 and the contact member 9 may be achieved by at least one protrusion 31 .

[0034] The elastic member 3 is made of a metal material with low vibration attenuation. The material will be described in detail below. A piezoelectric element can be appropriately used as the electromechanical energy conversion element 4 and is bonded to the elastic member 3 using an adhesive. The piezoelectric element as the electromechanical energy conversion element 4 is made of a plate-like piezoelectric ceramic, which is provided with electrodes of a predetermined shape formed on both sides thereof. A driving voltage (alternating current (AC) voltage) with a predetermined frequency from a flexible printed circuit board 5 is applied to the electrodes of the electromechanical energy conversion element 4.

[0035] Reference Figure 3 The holding member 6 for holding the vibration member 2 is arranged below the vibration member 2. The pressure spring 7 can be applied as a member for pressurizing the vibration member 2 toward the contact member 9. Figure 3 The holding member 6 is pressurized in the Z direction, and the reaction force exerted on the pressurizing spring 7 is received by the base 8.

[0036] Preferably, a conical coil spring is used as the pressurizing spring 7 to reduce the size of the vibration actuator 100 in the Z direction. The coil shape is shown in a simplified manner. The pressurizing spring 7 applies a predetermined pressurizing force (several hundred gf according to the present exemplary embodiment) to the vibration member 2.

[0037] The method for positioning the vibration member 2 in the X direction and the Y direction will be described below. The loose fitting portions 61-1, 61-2, 61-3 and 61-4 arranged on the holding member 6 are fitted into the four extension portions 34-1, 34-2, 34-3 and 34-4 of the elastic member 3 extending in the X direction. This structure prevents the vibration member 2 from moving in the X direction and the Y direction relative to the pressure spring 7 without excessively interfering with the vibration in the Z direction. The loose fitting portion 61 loosely supports the four extension portions 34-1, 34-2, 34-3 and 34-4 at the four corners of the vibration member 2, thereby providing a solid support structure.

[0038] like Figure 2 As shown, the contact member 9 is held by the contact member holder 10. The side surfaces along the longitudinal direction of the contact member holder 10 are provided with two different ball rails 12-1 and 12-2, which are used to hold three different balls 11-1, 11-2 and 11-3. In this state, by fixing the ball rails 12-1 and 12-2 to the base 8, the integral body of the contact member 9 and the contact member holder 10 can move along the X direction relative to the parts outside the integral body. In particular, the vibration of the vibration member 2 in contact with the contact member 9 causes the vibration member 2 and the integral body (contact member 9 and contact member holder 10) to move along the X direction. Figure 2 Attaching an output transfer unit having a desired shape to the contact member holder 10 enables the output to be transmitted to the outside, thereby allowing the vibration actuator 100 to perform its actuator function.

[0039] The following will refer to Figure 5 The vibration mode activated by the vibration member 2 is described. Figure 5 The vibration member 2 in the embodiment is constructed as discussed in Japanese Patent No. 6938218 and has the same operating principle as the vibration member 2 according to the present exemplary embodiment. According to the present exemplary embodiment, an AC voltage is applied to the electromechanical energy conversion element 4 via a flexible printed circuit board 5. This activates the out-of-plane bending vibration with two different vibration modes on the vibration member 2 to produce a combined vibration of these vibrations. These vibration modes (vibration mode A and vibration mode B described below) cause vibrations between adjacent nodes.

[0040] Vibration mode A (first vibration mode) is a first out-of-plane bending vibration mode in which two different nodes appear parallel to the X direction as the longitudinal direction of the vibration member 2 across two protrusions. The vibration in vibration mode A causes the two protrusions to shift in the Z direction as the pressurization direction. Vibration mode B (second vibration mode) is a second out-of-plane bending vibration mode in which three different nodes appear approximately parallel to the Y direction as the lateral direction of the vibration member 2. The vibration in vibration mode B causes the two protrusions to shift in the X direction. Vibration mode B is not limited to the second vibration mode, but can be an N-th vibration mode (N is an integer of 1 or 3 or more).

[0041] The vibration in the combined vibration mode A and the vibration mode B causes the elliptical or circular motion of the two protrusions 31-1 and 31-2 in the ZX plane. The contact member 9 is brought into pressure contact with the two protrusions 31-1 and 31-2 to generate a friction force in the X direction. This force generates a driving force (thrust) that enables either the vibration member 2 or the contact member 9 to move relative to the other. According to an exemplary embodiment, since the vibration member 2 is held by the technology described below, the contact member 9 moves in the X direction. In addition, the vibration member 2 can be configured to move in the X direction by fixing the position of the contact member 9 with a predetermined fixing member.

[0042] In order to efficiently drive the vibration actuator 100 , it is necessary to support the vibration member 2 without hindering the vibration (displacement) of the two vibration modes for activating the vibration member 2 .

[0043] To achieve this, it is desirable to support the vicinity of the nodes of the two vibration modes. Therefore, in order to pressurize and hold the common nodes of the two vibration modes activated by the vibration member 2, such as Figure 4 As shown, two protrusions 61 - 1 and 61 - 2 are disposed on the holding member 6 for holding the vibration member 2 .

[0044] The following will refer to Figure 6 , Figure 7and Figure 8 The detailed configurations and materials of the elastic member 3 and the friction member 13 are described. Figure 6 It is schematically shown Figure 3 A cross-sectional view of the vibration component 2 in FIG. Figure 7 It is schematically shown Figure 3 A cross-sectional view of a portion of the vibration member 2 in FIG. Figure 8 It is shown Figure 7 An exploded cross-sectional view of the vibration component 2 in FIG.

[0045] The configuration of the protrusion 31 is not limited. However, as a preferred example, the protrusion 31 may be a hollow protrusion that is formed integrally with the flat portion 31a of the elastic member 3 by a stamping process or a cutting process of a plate material constituting the elastic member 3. As another example, other members may be prepared as the protrusion 31 and arranged by welding or bonding.

[0046] Each of the protrusions 31 is formed of a cylindrical wall portion 31b and a disk portion 31c as a top portion, the outer peripheral side of which is supported by the wall portion 31b. The disk portion 31c has a thickness that provides spring characteristics that deform in the Z direction by a Z direction load when in contact with the contact member 9.

[0047] like Figure 7 As shown, the first recess 32 having a cylindrical shape is formed as a depression at the center of the disk portion 31c on the disk portion 31c, and the second recess 33 having a truncated cone shape is formed on the bottom surface of the first recess 32 to penetrate the disk portion 31c. The second recess 33 has a truncated cone shape, and its diameter decreases from the first recess 32 in the Z direction. Each of the friction members 13 (13-1 and 13-2) having an approximately spherical shape contacts an inclined surface 33a as a side wall of the second recess 33 having a truncated cone shape in an approximately circumferential form on the curved surface 13b. The friction member 13 is fixed by an adhesive (not shown). The side wall of the second recess 33 may partially form an inclined surface and partially form a cylindrical shape.

[0048] By making the inclined surface 33a of the second recess 33 having a truncated cone shape contact with the curved surface 13b of the friction member 13, the friction member 13 and the disc portion 31c can be accurately positioned in the X direction, the Y direction and the Z direction. Since the gap between the first recess 32 and the second recess 33 is filled with an adhesive, the friction member 13 can be firmly fixed. Since the diameter of the first recess 32 is larger than the diameter of the friction member 13, an adhesive pool is provided, so the friction member 13 can be more firmly fixed. Since the first recess 32 and the second recess 33 are arranged on the disc portion 31c, the adhesive drips into the adhesive pool during bonding. This can prevent the adhesive from covering the friction member 13. This makes it possible to avoid contact between the unhardened adhesive and the contact member 9. The Young's modulus of the metal material constituting the disc portion 31c is low, and the adhesive has little effect on the spring properties of the disc portion 31c. Therefore, as long as the adhesive does not contact the contact member 9, the adhesive can protrude from the first recess 32 and the second recess 33. This configuration can firmly fix the friction member 13 with high precision and improve the friction driving force to the contact member 9 of the vibration member 2, thereby achieving efficient and stable driving even in a vacuum environment.

[0049] The friction member 13 has an approximately spherical shape formed by cutting a portion of the spherical shape. The cross section of the friction member 13 is a friction surface 13a that contacts the contact member 9. Since the friction surface 13a is a flat surface with a predetermined area, the friction member 13 and the contact member 9 are in surface contact with each other, rather than point contact, thereby reducing contact surface pressure and wear.

[0050] When the vibration actuator 100 is driven, the contact state between the friction surface 13a and the contact member 9 is constantly changing. In this change process, the surface contact between the friction surface 13a and the contact member 9 on a larger area can further improve the wear resistance. Since the contact member 9 applies a pressure to the friction surface 13a in the Z direction, the friction surface 13a is used as a loading point, and the disc portion 31c is bent in the Z direction. Since the disc portion 31c has a structure (cylindrical support structure) supported at its opposite ends, wherein the outer periphery is supported by the cylindrical wall portion 31b, the friction surface 13a is displaced in the Z direction while remaining parallel to the XY plane.

[0051] This allows substantially the entire surface of the friction surface 13a to contact the contact member 9 during the deformation of the disc portion 31c, thereby reducing the contact surface pressure and wear. These effects improve wear resistance and achieve stable driving. In particular, the above configuration has a great effect in a vacuum environment where wear resistance problems become apparent.

[0052] The material of the elastic member 3 will be described below. Preferably, the elastic member 3 has high machinability due to its complex shape. Materials with high Vickers hardness (HV) are difficult to process and are therefore not suitable for the elastic member 3. Preferably, the material of the elastic member 3 has low Vickers hardness. In order to achieve stable drive in a vacuum environment by reducing the interference of electron beams in a vacuum device and reducing magnetic interference with other devices in an artificial satellite, preferably, the elastic member 3 is made of non-magnetic material. Example metal materials that meet these conditions include aluminum alloys (about HV120 or less), brass (about HV160 or less) and austenitic stainless steel (about HV200 or less). The above-mentioned Vickers hardness (HV) values ​​are representative values ​​and are not limited thereto.

[0053] The material of the friction member 13 will be described below. Since the friction member 13 is frictionally driven while the friction surface 13a is in contact with the contact member 9, it is preferred that the material of the friction member 13 has high wear resistance and a high friction coefficient. Since wear resistance is largely affected by the material of the mating member, wear resistance is related to Vickers hardness (HV) although there is no clear indicator. Since the higher the Vickers hardness, the higher the wear resistance tends to be, it is preferred that the friction member 13 is made of a material with a high Vickers hardness. On the other hand, since the elastic member 3 is required to have good machinability, it is preferred that the material of the elastic member 3 has a low Vickers hardness. Therefore, it is preferred that the Vickers hardness of the friction member 13 is higher than the hardness of the elastic member 3.

[0054] Examples of available materials for the friction member 13 include hardened steel materials with high Vickers hardness, nitrided steel materials, ceramics, and hard alloys. However, the available materials are not limited thereto. The Vickers hardness of the friction member 13 needs to be higher than the Vickers hardness of the elastic member 3. Examples of available materials include glass, nickel alloys, cobalt alloys, and cermets.

[0055] Applicable hardened steel materials include martensitic stainless steel SUS440C and SUS420J2 and high carbon chromium bearing steel material SUJ2 with a Vickers hardness of about HV600 to HV800. Applicable nitriding steel materials include austenitic steel materials of stainless steel and other steel materials (including Vickers hardness of about HV800 to HV1200). Applicable ceramics include aluminum, zirconium oxide, silicon nitride and silicon carbide with a Vickers hardness of about HV1000 to HV2000. Applicable cemented carbides include: tungsten carbide with a Vickers hardness of about HV1500 to HV2000 using cobalt and nickel as bonding materials. Applicable glass includes: soda glass with a Vickers hardness of about HV500, quartz with a Vickers hardness of HV1000, and sapphire and ruby ​​with a Vickers hardness of HV2000 or higher. The above Vickers hardness (HV) values ​​are representative values ​​and the present disclosure is not limited thereto.

[0056] In order to improve the workability of the elastic member 3 and the wear resistance of the friction member 13, preferably, the Vickers hardness of the friction member 13 is at least twice that of the elastic member 3. More preferably, the Vickers hardness of the friction member 13 is at least three times that of the elastic member 3.

[0057] Fig. 9 1 is an exploded perspective view showing a portion of the vibration member 2 before the friction surface 13a is formed. Before the friction surface 13a is formed, the friction member 13 is a spherical precision ball 14. Preferably, the precision ball 14 is a ball used for ball bearings, physical and chemical experimental tools, and ballpoint pens. The precision ball 14 to be used has high Vickers hardness, high wear resistance, and high dimensional accuracy.

[0058] The method for forming a friction member 13 having a friction surface 13a in surface contact with the contact member 9 will be described below. The vibration member 2 is made of a spherical precision ball 14 that is bonded to the elastic member 3 and built into the vibration actuator 100. Then, the vibration actuator is driven. Therefore, the precision ball 14 is worn due to friction with the contact member 9 in a short time. Therefore, the contact state changes from point contact to surface contact, and the friction member 13 having the friction surface 13a is formed. In this case, the Vickers hardness of the contact member 9 is made higher than the Vickers hardness of the friction member 13, so that the formation time of the friction surface 13a can be shortened while reducing the wear of the contact member 9.

[0059] After the precision ball 14 is bonded to the elastic member 3 , a portion of the precision ball 14 may be scraped off by a grinding process to form the friction surface 13 a .

[0060] By the drive of the vibration actuator 100, the contact position between the contact member 9 and the vibration member 2 moves in the X direction. Therefore, the friction surface 13a of the contact member 9 and the vibration member 2 is formed as a line with a predetermined width in the X direction. If the wear depth of the friction surface 13a of the contact member 9 is greatly different according to the position, the friction state changes according to the position relative to the vibration member 2, resulting in uneven driving performance of the vibration actuator 100. In order to prevent uneven driving performance, preferably, the wear depth of the friction surface 13a of the contact member 9 is prevented as much as possible. In order to reduce the wear of the contact member 9, preferably, the contact state of the friction member 13 of the vibration member 2 is immediately transformed from point contact to surface contact by wear in the initial driving stage. Therefore, preferably, the wear resistance of the friction member 13 is lower than the wear resistance of the contact member 9, that is, the friction member 13 is easy to wear. Preferably, the Vickers hardness of the contact member 9 is higher than the Vickers hardness of the friction member 13. Preferably, the elastic member 3, the friction member 13 and the contact member 9 have higher Vickers hardness in turn. Examples of available materials for the contact member 9 include nitriding-treated steel materials such as stainless steel, ceramics, and metal materials coated with ceramics.

[0061] Preferably, at least one of the friction member 13 or the contact member 9 is mainly made of a non-metallic inorganic material. More preferably, both members are made of a non-metallic inorganic material. Preferably, at least one of the friction member 13 or the contact member 9 is mainly made of a non-metallic inorganic material, resulting in a wear form that does not use a metal oxide film formed by friction as a protective film. More preferably, at least the friction member 13 contains a non-metallic inorganic material.

[0062] More specifically, the friction member 13 and the contact member 9 do not require oxygen and moisture in the atmosphere, so that the wear resistance in the vacuum environment can be improved. The material mainly composed of non-metallic inorganic materials includes at least one material group of ceramics, cemented carbide, glass or cermet. Although cemented carbide uses cobalt or nickel as a bonding material, it is mainly composed of tungsten carbide and is included in the material mainly composed of non-metallic inorganic materials.

[0063] Motor performance and wear resistance depend on the material combination of friction member 13 and contact member 9. According to the inventors' consideration, motor performance and wear resistance in vacuum are favorable when the friction material of friction member 13 is hard alloy and the friction material of contact member 9 is ceramic of titanium nitride compound.

[0064] The cemented carbide used as the friction member 13 is composed of tungsten carbide (about 92%) with a Vickers hardness of HV1400 to HV1500, cobalt (about 8%), and other components (1% or less). The composition of the cemented carbide is not limited to these values. The cemented carbide is composed of tungsten carbide (60% to 97%) and other components using cobalt or nickel as a binder. The material of the friction member 13 may be mainly composed of cemented carbide, and partially composed of materials other than cemented carbide.

[0065] The coating of the titanium nitride compound used for the contact member 9 is TiSiN with a Vickers hardness of HV3000 to HV3500. However, the titanium nitride compound is not limited to TiSiN, but may be TiN or TiAlN. The substrate of the contact member 9 is SUS304 or SUS420J2 as stainless steel solidified by nitriding or hardening, and the TiSiN is coated with PVD. This treatment is intended to reduce the hardness difference between the stainless steel as the substrate and the TiSiN as the coating to improve adhesion. The substrate of TiSiN may be coated to improve adhesion. The substrate needs to be a metal material that can be ceramic coated.

[0066] Fig.10 is a cross-sectional view schematically showing a part of a first modification example of the vibration member 2 according to the present exemplary embodiment.

[0067] This modification does not include a cylindrical recess. Only a first recess 34 having a truncated cone shape is formed at the center of the disc portion 31d of the projection, and the first recess penetrates the disc portion 31d. The friction member 13 contacts the inclined surface 34a of the first recess 34 and is fixed to the inclined surface 34a by bonding. The configuration of this modification makes it possible to reduce the processing cost due to the simple shape of the recess.

[0068] Fig.11 is a cross-sectional view schematically showing a part of a second modification example of the vibration member 2 according to the present exemplary embodiment.

[0069] In this modification, the recess does not penetrate the disc portion. A first recess 35 having a cylindrical shape and a second recess 36 having a truncated cone shape are formed at the center of the disc portion 31e of the protrusion. The second recess 36 does not penetrate the disc portion 31e, but forms a bottom surface 31f. The friction member 13 contacts the inclined surface 36a of the second recess 36 and is fixed to the inclined surface 36a by bonding. Although Fig.11 The bottom surface 31f having a linear shape is shown, but the bottom surface 31f may have a curved surface. Since the recess does not penetrate the disk portion 31e, the configuration of the present modification has a shape suitable for press working, making it possible to reduce working costs in mass production.

[0070] Fig.12 is a cross-sectional view schematically showing a part of a third modification example of the vibration member 2 according to the present exemplary embodiment.

[0071] This modification has two different cylindrical recesses. A first recess 37 having a cylindrical shape and a second recess 38 having a cylindrical shape and a diameter smaller than that of the first recess 37 are formed at the center of the disc portion 31g of the raised portion. A slight inclined surface 38a is formed on the ridge line between the first recess 37 and the second recess 38. The friction member 13 contacts the inclined surface 38a and is fixed to the inclined surface 38a by bonding. More specifically, Fig.12 The structure in is realized as a slight inclined surface 38 a formed at a portion connecting the bottom surface of the first recess 37 and the inner wall of the second recess 38 .

[0072] The inclined surface 38a can be formed by chamfering in machining (pressing and cutting processes). Alternatively, after the corner is formed in machining, the inclined surface 38a can be formed by bringing the friction member 13 into contact with the corner to flatten the corner. The configuration of this modification simplifies the process of forming the inclined surface 38a and reduces the machining cost.

[0073] Fig.13 is a perspective view schematically showing a fourth modification of the vibration member 2 according to the present exemplary embodiment. Fig.14 It is schematically shown Fig.13 A cross-sectional view of a portion of the vibration member 2 in FIG. Fig.15 yes Fig.14 The cross-sectional view of the friction member 13 is omitted.

[0074] This modification uses a friction member 113 having a substantially cylindrical shape. The friction member 113 is provided with a flat friction surface 113a formed by cutting a portion of the cylindrical curved surface. Each of the raised portions 131 (131-1 and 131-2) is a hollow raised portion formed integrally with the flat portion 131a of the elastic member 3. The raised portion 131 has a structure supported at opposite ends where both edges in the Y direction are open, and a gate shape with the top supported by the two edges. The raised portion 131 includes: a wall portion 131b (131b-1 and 131b-2) arranged in the X direction, and a rectangular plate 131c as a top with each edge supported by the wall portion 131b. The rectangular plate 131c has a thickness that provides a spring characteristic that is deformed in the Z direction by a Z direction load when in contact with the contact member 9. A first recess 132 of a rectangular shape is formed at the center of the rectangular plate 131c in the X direction. The second recess 133 is formed on the bottom surface of the first recess 132 and penetrates the rectangular plate 131c. The side wall of the second recess 133 arranged in the X direction is an inclined surface 133a, whose width decreases from the first recess 132 along the Z direction. Each of the friction members 113 (113-1 and 113-2) having a cylindrical shape contacts the inclined surface 133a in an approximately linear form on the curved surface 113b and is bonded by bonding. According to the configuration of this modified example, extending the friction member 113 in the Y direction increases the contact area to reduce the contact surface pressure, thereby improving the wear resistance.

[0075] The vibration actuator 100 according to this exemplary embodiment has achieved improved wear resistance and stable drive in a vacuum environment. Therefore, the vibration actuator 100 can be installed on an artificial satellite used in outer space and a vacuum device for production and analysis. For example, for an artificial satellite, the vibration actuator 100 can be used for linear drive and rotation drive of camera lenses, image sensors and communication antennas. For a vacuum device, the vibration actuator 100 can be used for linear drive and rotation drive of components such as a stage in a vacuum chamber. Fig.16 1 is a schematic diagram showing a moving object having a body on which a vibration actuator 100 is installed. Fig.16As shown, the vibration actuator 100 according to the present exemplary embodiment can be installed on a mobile object 300 orbiting a celestial body (for description, the size of the mobile object 300 is emphasized). More specifically, the mobile object 300 having a fuselage 200 capable of navigating in the outer space and the above-mentioned vibration actuator 100 can be used for the above-mentioned various applications. In this case, the construction of the control unit for controlling the fuselage 200 and the vibration actuator 100 is not particularly limited, but can be arranged in a desired manner according to the application. The control unit can be installed on the fuselage 200, or can be installed on the ground portion of a celestial body (such as the earth) separated from the fuselage 200. This makes it possible to construct a mobile object control system including a mobile object and a control unit for controlling the mobile object.

[0076] Fig.17 1 is a schematic diagram showing a vacuum device for driving a component in a vacuum chamber by using a vibration actuator 100 of the present invention. The vacuum device can drive a component 400 such as a stage in a vacuum chamber by using the vibration actuator 100. The vacuum device generates a vacuum state in a vacuum chamber isolated from ambient air by using a vacuum pump connected to the vacuum chamber. Under a vacuum environment, the component 400 can be driven by the vibration actuator 100 of the present invention.

[0077] The present disclosure makes it possible to provide a vibration actuator capable of improving wear resistance, thereby enabling stable driving in a vacuum environment such as outer space and a vacuum apparatus.

[0078] While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A vibration actuator, comprising: a vibration member having a rectangular elastic member and an electromechanical energy conversion element; as well as a contact member in contact with the elastic member, The contact member and the vibration member move relative to each other due to the vibration of the vibration member. wherein a flat portion and a convex portion are formed on the elastic member, the convex portion has a top portion and a wall portion, and each edge or the entire circumference of the top portion is supported by the wall portion, The top is provided with a friction member different from the elastic member to contact with the contact member. wherein the friction member is a sphere or a cylinder, and Wherein, the friction member is supported by an inclined surface formed on the top portion.

2. The vibration actuator according to claim 1, wherein the top portion is a disk, and the wall portion is a cylinder for supporting an outer circumference of the top portion.

3. The vibration actuator according to claim 1, wherein: The friction member is provided with a flat friction surface which is a cut portion of the curved surface of the friction member, and the friction member is in contact with the contact member on the friction surface.

4. A vibration actuator comprising: a vibration member having a rectangular elastic member and an electromechanical energy conversion element; as well as a contact member in contact with the elastic member, The contact member and the vibration member move relative to each other due to the vibration of the vibration member. A flat portion and a hollow convex portion are formed on the elastic member, and a friction member different from the elastic member is provided on the top of the convex portion to contact with the contact member. Wherein, the friction member is a sphere or a cylinder, Wherein, the friction member comprises a non-metallic inorganic material, and Wherein, the Vickers hardness of the friction component is higher than the Vickers hardness of the elastic component.

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

6. The vibration actuator according to claim 4, wherein: The Vickers hardness of the contact member is higher than the Vickers hardness of the friction member.

7. A vibration actuator according to any one of claims 1 to 6, wherein: The elastic member includes a non-magnetic material.

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

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

10. The vibration actuator according to claim 1 or 4, wherein: The raised portion having the top portion and the wall portion is integrally formed.

11. The vibration actuator according to claim 1 or 4, wherein: The material of the friction member includes cemented carbide, and the material of the contact member includes a metal material coated with a titanium nitride compound.

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

13. The vibration actuator according to claim 1 or 4, wherein: The vibration actuator operates in a vacuum environment.

14. A mobile object, comprising: a fuselage configured to navigate in outer space; as well as A vibration actuator according to claim 1 or 4.

15. A mobile object control system, comprising: The mobile object according to claim 14; as well as A control unit of the mobile object.

16. A vacuum device comprising: Vacuum chamber; a vacuum pump configured to be connected to the vacuum chamber; as well as A vibration actuator according to claim 1 or 4.

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