Vibration actuators and electronic equipment

Abstract

To provide a vibration type actuator that is driven at a stable speed.SOLUTION: A vibration type actuator for solving the above problem comprises a vibrator that has an electrical-mechanical energy conversion element and an elastic body, and a contact body that is brought into contact with the elastic body. The vibration type actuator has the contact body and the vibrator relatively moved in a first direction by vibrations of the vibrator. The elastic body has a rectangular plate part along the first direction, a protrusion that protrudes in a second direction crossing the first direction, and an extension part that is extended from the plate part in a direction along the first direction. Additionally, a support member, which abuts on at least one of the extension part and the plate part and which supports the vibrator so that the vibrator can move along the second direction, is also provided. Furthermore, the elastic body is partially provided with a surface abutting on the support member along the second direction, and an inclined part adjoining the abutting surface and inclined in a direction of getting away from the support member with respect to the abutting surface.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a vibration type actuator and an electronic device.

Background Art

[0002] Vibration type actuators using electro-mechanical energy conversion elements are known in various configurations. For example, there is known a vibration type actuator that is driven by bringing a vibrator, in which an electro-mechanical energy conversion element is joined to an elastic body (hereinafter referred to as a diaphragm) provided with two protrusions, into pressure contact with a driven body.

[0003] This vibration type actuator generates an elliptical motion or a circular motion at the tips of the two protrusions in a plane including the direction connecting the two protrusions and the protruding direction of the protrusions by applying a predetermined alternating voltage to the electro-mechanical energy conversion element. As a result, the driven body receives a frictional driving force from the two protrusions, and the vibrator and the driven body can be relatively moved in the direction connecting the two protrusions.

[0004] The vibration type actuator described in Patent Document 1 has a configuration in which the vibrator is held by bringing the end surfaces of the rectangular portion and the extending portion of the diaphragm into contact with and loosely fitting on a plurality of protrusion portions provided on a support member, and realizes miniaturization in the motor driving direction and reduction of the risk of abnormal noise generation.

[0005] In addition, the vibration type actuator described in Patent Document 2 focuses on the joining method of the diaphragm and the electro-mechanical energy conversion element, and devises measures for shortening the processing time of the polishing process and improving the shape accuracy of the diaphragm after polishing by defining the direction of burrs generated in press molding.

[0006] On the other hand, in recent years, the application of vibration type actuators to various uses has been demanded, and further improvement in the stability of the driving speed of the vibration type actuator itself has become an issue.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2020-198658 [Patent Document 2] Japanese Patent Publication No. 2015-43670 [Overview of the project] [Problems that the invention aims to solve]

[0008] This invention was made to solve the above-mentioned problems and aims to provide a vibration-type actuator that operates at a stable speed. [Means for solving the problem]

[0009] The vibration-type actuator of the present invention, which solves the above problems, A vibratory actuator comprising an electromechanical energy conversion element and an elastic body, a vibrator having an elastic body, and a contact body in contact with the elastic body, wherein the contact body and the vibrator move relative to each other in a first direction due to the vibration of the vibrator, The elastic body has a rectangular plate portion along the first direction, a projection portion that protrudes in a second direction intersecting the first direction, and an extension portion that extends from the plate portion in a direction along the first direction. The system further includes a support member that abuts against at least one of the extension portion and the plate portion and supports the vibrator so that it can move along the second direction, A portion of the elastic body is provided with a contact surface with the support member along the second direction, and an inclined portion adjacent to the contact surface that is inclined away from the support member with respect to the contact surface. [Effects of the Invention]

[0010] According to the present invention, a small vibration-type actuator that operates at a stable speed can be provided. [Brief explanation of the drawing]

[0011] [Figure 1]Perspective assembly view of the vibration type actuator in Example 1 of the present invention [Figure 2] Exploded perspective view of the vibration type actuator in Example 1 of the present invention [Figure 3] Figure for explaining the vibration mode in Example 1 of the present invention [Figure 4] Perspective assembly view of the vibrator and the support member in Example 1 of the present invention [Figure 5] Plan assembly view of the vibrator and the support member in Example 1 of the present invention [Figure 6] Plan assembly view of the vibrator and the piezoelectric element bonding positioning parts in Example 1 of the present invention [Figure 7] Cross-sectional view showing the side surface of the elastic body contacting the support member in Example 1 of the present invention [Figure 8] Cross-sectional view showing the side surface of the elastic body contacting the support member in Example 2 of the present invention [Figure 9] Exploded perspective view of the vibration type actuator in Example 3 of the present invention [Figure 10] [[ID=Z7]]Cross-sectional view of the vibration type actuator in Example 3 of the present invention [Figure 11] Top view (a) and block diagram (b) showing the schematic configuration of an imaging device including a vibration type actuator according to an embodiment of the present invention [Figure 12] Top dead center view (a), bottom dead center view (b), and enlarged view of the shearing part (c) showing the shearing process in press molding in Example 5 of the present invention [Figure 13] Top view (a) and enlarged top view of the extending part (b) showing the trimming process of the elastic body in Example 5 of the present invention [Figure 14] Side view showing the end face shape of the elastic body in Example 5 of the present invention [Figure 15] Enlarged view (a) showing the state of burrs at the contact part between the elastic body and the support member in Example 5 of the present invention, and enlarged view (b) showing the state of crushed burrs [Figure 16] Top dead center view (a), view during processing (b), and bottom dead center view (c) showing the surface pressing process in press molding in Example 5 of the present invention [Figure 17]Enlarged view showing the inclined surface of the elastic body in Example 5 of the present invention [Figure 18] Enlarged view (a) showing secondary shear on the contact surface between the elastic body and the support member in Example 5 of the present invention, and enlarged view (b) showing the inclined surface

Mode for Carrying Out the Invention

[0012] The vibration type actuator according to the present invention for solving the above problems includes a vibrator having an electro-mechanical energy conversion element and an elastic body, and a contact body in contact with the elastic body, and is a vibration type actuator in which the contact body and the vibrator relatively move in a first direction due to the vibration of the vibrator.

[0013] The elastic body has a rectangular plate portion along a first direction, a protrusion portion protruding in a second direction intersecting the first direction, and an extension portion extending from the plate portion in a direction along the first direction.

[0014] Furthermore, it further includes a support member that abuts at least one of the extension portion and the plate portion and supports the vibrator movably along the second direction. And a contact surface with the support member along the second direction and an inclined portion adjacent to the contact surface and inclined in a direction away from the support member are provided on a part of the elastic body.

[0015] A vertical surface and an inclined surface are provided on the end face of the elastic body, which can reduce the possibility and degree of interference with the support member when the burr of the elastic body is crushed in the pressing process or the burr of the elastic body protrudes due to the driving of the actuator.

[0016] Also, it can be expected that the tip of the extension portion used for positioning when adhering the electro-mechanical energy conversion element to the elastic body will not interfere with the elastic body positioning jig even if the burr of the elastic body is crushed in the pressing process.

[0017] The vibration-type actuator may be one in which multiple vibrators linearly drive a common contact body, or one in which multiple vibrators are arranged circumferentially to rotate a common contact body.

[0018] Regarding the drive speed, by optimizing the shape of the diaphragm's end in the vibrator's support configuration and changing the contact conditions between the support member and the diaphragm, frictional resistance due to interference between the two can be reduced, and further stability of the drive speed can be expected. Embodiments of the present invention will be illustrated and explained in detail below with reference to the drawings. [Examples]

[0019] This embodiment is an example of applying the present invention to a linearly driven linear vibration actuator, and its details will be explained using Figures 1 to 7. First, Figure 1 is an assembled perspective view of the vibration actuator 1 in Embodiment 1 of the present invention, and Figure 2 is an exploded perspective view. Here, the direction of movement of the contact body, the slider 9, is defined as X, the direction of pressure as Z, and the direction perpendicular to the X and Z directions as Y.

[0020] The term "contacting body" refers to a member that comes into contact with a vibrating body and moves relative to the vibrating body due to vibrations generated in the vibrating body. The contact between the contacting body and the vibrating body is not limited to direct contact without any other member interposed between the contacting body and the vibrating body. The contact between the contacting body and the vibrating body may be indirect contact with other members interposed between the contacting body and the vibrating body, as long as the contacting body moves relative to the vibrating body due to vibrations generated in the vibrating body. The "other member" is not limited to a member independent of the contacting body and the vibrating body (for example, a high-friction material made of a sintered body). The "other member" may also be a surface-treated portion formed on the contacting body or the vibrating body by plating, nitriding, or the like.

[0021] An elastic body 3 and a piezoelectric element 4, which is an electromechanical energy conversion element, are fixed together with an adhesive or the like. Furthermore, a flexible printed circuit board 5 is fixed to the piezoelectric element 4 on the opposite side from the elastic body 3, and these together constitute the oscillator 2. The flexible printed circuit board 5 is fixed using an anisotropic conductive paste or anisotropic conductive film that allows current to flow only in the Z direction.

[0022] The elastic body is composed of a substantially rectangular plate portion, one or more projections that protrude from the plate portion outside the plane constituting the plate portion, i.e., in a direction intersecting the direction of movement, and one or more extensions that extend from the plate portion in a direction along the plane, i.e., along the direction of movement.

[0023] The direction of movement is the first direction, and the direction of intersection is the second direction.

[0024] The elastic body 3 is preferably made of a material that has low vibration damping properties, such as metal or ceramics. Regarding the manufacturing of the elastic body 3, the protrusions 3a may be integrally formed by press molding or cutting, or they can be manufactured separately and later fixed by welding or adhesive. Furthermore, multiple protrusions 3a may be provided, as in this embodiment, or there may be just one.

[0025] The piezoelectric element 4 uses, for example, lead zirconate titanate. Alternatively, it may be made primarily of lead-free piezoelectric materials such as barium titanate or bismuth sodium titanate. Lead-free means that the lead content is 1000 ppm or less. Electrode patterns (not shown) are formed on both sides of the piezoelectric element 4, and power is supplied from the flexible printed circuit board 5. A support member 6, a pressure spring 7, and a base 8 that receives the pressure from the pressure spring 7 are provided as support members for the vibrator 2.

[0026] In terms of specific configuration, a support member 6 is provided below the vibrator 2 in Figure 1 to pressurize and support the vibrator 2. The support member is subjected to a pressurizing force in the Z direction by a pressurizing spring 7, and the reaction force is received by the base 8, which is a pressurizing receiving member. A conical coil spring is used for the pressurizing spring 7 in order to miniaturize the vibrating actuator 1 in the Z direction. Note that the coil shape is simplified in the illustration.

[0027] A slider 9, which is a contact body, is provided above the vibrator 2 and is in pressurized contact with the projection 3a of the elastic body 3. The slider 9 is fixed to the slider holder 10 and is driven together with the vibrator 2 in the X direction relative to it. Rubber for vibration damping may be provided between the slider 9 and the slider holder 10. The slider 9 is made of a highly wear-resistant metal, ceramic, resin, or a composite material thereof. Nitrided stainless steel such as SUS420J2 is particularly preferred from the viewpoint of wear resistance and mass production.

[0028] The slider holder 10 and the ball rail 12 are provided with three pairs of upper and lower rails that hold the three balls 11 in place. The ball rail 12 is fixed to the base 8, allowing the slider 9 and slider holder 10 to move in the X direction relative to other components. Output is transmitted to the outside by attaching an output transmission unit of a desired shape to the slider holder 10. In this embodiment, the vibrator 2 is fixed and the slider 9 moves, but it is also possible to fix the slider 9 and move the vibrator 2.

[0029] Next, the vibration modes excited in the oscillator 2 will be explained using Figures 3(a) and 3(b). In this embodiment, an AC voltage is applied to the piezoelectric element 4 through the flexible printed circuit board 5 to excite the oscillator 2 with two different out-of-plane bending vibrations, and a vibration is generated by combining these vibrations.

[0030] The first vibration mode, 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 transducer 2. The vibration in Mode A causes the two protrusions 3a to be displaced in the Z direction, which is the direction of pressure. The second vibration mode, 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 direction of the transducer 2. The vibration in Mode B causes the two protrusions 3a to be displaced in the X direction.

[0031] By combining the vibrations of modes A and B, the two protrusions 3a perform elliptical or circular motion in the ZX plane. By pressurizing the slider 9 into contact with these protrusions 3a, a frictional force is generated in the X direction, creating a driving force (thrust) that moves the vibrator 2 and the slider 9 relative to each other. In this embodiment, since the vibrator 2 is held by the method described later, the slider 9 moves in the X direction.

[0032] In order to efficiently drive the vibration actuator 1, it is necessary to support the vibrator 2 without hindering the vibration (displacement) of the two vibration modes that excite the vibrator 2. For this reason, it is desirable to support the vicinity of the nodes of these two vibration modes. For this reason, two protrusions 6a are provided on the support member 6, as shown in Figure 2, in order to selectively pressurize and hold the common node of the two vibration modes that are excited by the vibrator 2. Figure 3 shows the contact position and the node position in each vibration mode. Six locations appear where the nodes of the two vibration modes overlap, but by applying pressure at the two longitudinal central points, an equalization function around the Y axis is provided, making it possible to substantially equalize the contact between the vibrator 2 and the slider 9.

[0033] Figure 4 shows an enlarged perspective view of the vibrator and support member, and Figure 5 shows a plan view. The support member 6 is provided with four loose fitting portions 62. In the loose fitting portions 62, the columnar portions 6b loosely fit and support the four corners of the elastic body. The corners that serve as support points do not necessarily have to include the vertices of the four corners of the elastic body.

[0034] When the rectangular plate portion and extension portion of the transducer 2 are projected onto the XY plane, the support member 6 supports (loosely fits) the elastic body with play in at least one of the X and Y directions relative to the outer periphery. This loosely fitting portion 62 serves to position the transducer 2 during assembly and also functions as a stopper when any external force is applied to the slider 9.

[0035] Figure 5(a) shows the oscillator positioned in the center, with all four columnar portions 6b of the support member 6 having play, while Figure 5(b) shows the state where one side is abutted by an external force (arrow in the figure). When the elastic body 3 is formed by press working, burrs and burrs often occur on the edges of the outer shape due to the punching process. Figure 7 illustrates the contact surface and inclined portion of the support member 6 and the elastic body 3 (not shown), showing their XZ cross-sectional shapes. The elastic body 3 has a substantially rectangular plate portion 30 and a total of four extension portions 32 extending from the plate portion 30, two each in the positive and negative X directions.

[0036] In this embodiment, when the cut-out surface (the XY plane portion of the elastic body 3) and the support member come into contact, as shown in Figure 5(b), it is necessary to reduce or eliminate frictional resistance due to interference. For example, if a burr on the elastic body 3 is crushed and protrudes along the XY plane portion, and the protruding burr bites into the columnar portion 6b of the support member, it particularly hinders the feed vibration and deteriorates the motor performance. Also, when positioning the piezoelectric element with an adhesive jig 13 as shown in Figure 6 when bonding the piezoelectric element to the elastic body, it is necessary to ensure that the tip surface 31b of the extension portion 32 does not have a burr that protrudes and interferes with the jig.

[0037] Looking at the XZ cross-section of the elastic body 3 shown in Figure 7(a), it is evident that the burr 3D protrudes downward in the Z direction. A feature of this embodiment is that a fracture surface 3C is provided on the lower side of the shear surface 3A, which is the contact surface of a support member (not shown), with an appropriate inclination relative to the shear surface 3A so as to move away from the support member (not shown). With such a fracture surface 3C provided, even if the burr 3D deforms due to polishing of the bottom surface of the elastic body 3, and the burr 3D' of the elastic body 3 protrudes to the left in the figure as shown in Figure 7(b), the possibility of it protruding beyond the shear surface 3A is reduced.

[0038] The burr 3D', which is crushed by another process, should not protrude to the left of the shear surface 3A, or should protrude only by a small percentage. Therefore, the fracture surface 3C below the shear surface A needs to have an appropriate slope. This slope is adjusted by the clearance between the die and punch of the mold. A larger clearance results in a larger slope, but also a larger sag 3B. While a large sag 3B is not a problem for the extension 32, if the rectangular section to which the piezoelectric element is bonded has a large sag, the sag will remain even after polishing the bonding surface, potentially negatively affecting the bonding strength. Therefore, the sag 3B of the edges of the bonding surface should be kept small, and the burr 3D' should not protrude beyond the shear surface 3A. The tip surface 31b of the extension 32 is not a bonding surface, so the clearance can be increased to increase the slope of the cross-section. Note that if the clearance is increased only for the extended portion 32 in the area indicated by the arrow in Figure 5(b), the balance of the punching process will be poor. Therefore, the clearance amount should take into account the drooping 3B of the adhesive surface edge.

[0039] As described above, the present invention provides a vibratory actuator that is smaller, has fewer parts, and is capable of stable operation compared to conventional actuators.

[0040] In the linear vibration actuator of the present invention, the method for generating elliptical or circular motion at the contact surface is not limited to the method described above. For example, vibrations of different bending vibration modes may be combined, or vibrations of a longitudinal vibration mode that expands and contracts the elastic body in the longitudinal direction may be combined with vibrations of a bending vibration mode.

[0041] This method generates elliptical and circular motion on the contact surface by combining a vibration mode that displaces the contact surface in the direction of movement of the driven object and a vibration mode that displaces the contact surface in the direction of pressure. Any drive method can be used as long as it has a common node for pressurizing and holding.

[0042] Furthermore, to improve thrust, the slider may be sandwiched between two oscillators. [Examples]

[0043] This embodiment will be explained with reference to Figure 8. The elastic body shown in Figure 8 has inclined portions that are inclined away from the support member, and are provided next to each other, with inclined portions having different inclination angles or different curvatures.

[0044] As an example of a method for manufacturing an elastic body shown in Figure 8, a face-punching process is added to the punching process of the elastic body 3 of the vibrating actuator in Embodiment 1 of the present invention. The cross-sectional shape of the side surface formed by face-punching is configured such that the burr 3D is crushed and an inclined surface 3E is formed. That is, a first inclined surface 3C and a second inclined surface 3E are formed. Due to face-punching, the burr 3D undergoes plastic flow toward the shear surface side 3C, but since the sharp burr is eliminated, adverse effects on motor performance can be further avoided.

[0045] Furthermore, as shown in Figure 8, it is also possible to provide a sag portion composed of sag 3B, and to further arrange a sag portion adjacent to the contact surface on the side opposite to the side where the inclined portion is provided, relative to the contact surface.

[0046] In that case, it is preferable to have an electromechanical energy conversion element placed on the surface of the elastic plate portion closer to the sagging portion of the sagging portion and the inclined portion. [Examples]

[0047] This embodiment will be explained using Figures 9 and 10. First, Figure 9 is an exploded perspective view of the vibratory actuator in Embodiment 3 of the present invention, where the radial direction is defined as X, the rotational direction as θ, and the pressurizing direction as Z. Figure 10 is a cross-sectional view of the vibratory actuator in Embodiment 3 of the present invention, taken from the ZX direction.

[0048] A feature of this embodiment is that the three oscillators 202 (202-1, 202-2, and 202-3) are held on a ring base 206. The configuration and driving principle of the oscillators 202 are the same as in Embodiments 1 and 2, so a detailed explanation is omitted.

[0049] Three sets of protrusions and loose-fitting portions, performing the same functions as in Examples 1 and 2, are provided on the ring base 206 at 120-degree intervals, respectively, holding and loosely fitting the vibrator 202. The flexible printed circuit boards of the vibrator 202 are connected by a linked flexible printed circuit board (not shown), and the same driving voltage is applied to the piezoelectric elements.

[0050] The rotor 211, which is the driven body, is brought into contact with the projection of the vibrator 202, and the rotor 211 rotates due to the driving force generated in the tangential direction. Vibration-damping rubber 212 is positioned on the upper part of the rotor 211, and each is held in a state in which it can rotate integrally with the output transmission member 216.

[0051] On the other hand, the annular ring base 206 is combined with the inner cylinder 217 at a part not shown, and its movement in the axial direction and radial direction, as well as its rotation around the central axis, are restricted.

[0052] A pressure assist member 207 having a predetermined rigidity is provided at the lower part of the ring base 206, and the pressure applied by the support member, the wave washer 208, is made uniform. A pressure receiving member 209 is positioned at the lower part of the wave washer 208.

[0053] The pressure receiving member 209 engages with the inner cylinder 217 on its inner diameter side using a screw or bayonet mechanism. The vibration actuator 201 compresses the wave washer 208 by rotating the pressure receiving member 209 and moving it in the central axis direction. The structure from the ring base 206 to the output transmission member 216 is pressurized and clamped by the outer cylinder 213, the inner cylinder 217, and the pressure receiving member 209. A ball 214 and a retainer 215 are provided between the outer cylinder 213 and the inner cylinder 217 and the output transmission member 216, supporting the output transmission section 216 so that it can rotate while under pressure. The outer cylinder 213 and the inner cylinder 217 are connected by screwing the lid 210 to each other.

[0054] In this embodiment as well, the protrusions and loose fitting portions on the ring base 206 provide an equalization function around the X axis, simplifying the support structure for the transducer 202.

[0055] In this embodiment, we have described the case where there are three transducers 202, but this is not the only case; any number of transducers that can be placed on the ring base 6, one or more, is acceptable. [Examples]

[0056] The present invention can provide an electronic device comprising the aforementioned vibratory actuator and a member driven by this vibratory actuator.

[0057] Furthermore, the vibration actuator can be used, for example, for lens driving applications in imaging devices (optical instruments). Specifically, it is provided as an optical instrument comprising a vibration actuator and an optical element driven by this vibration actuator.

[0058] Therefore, as an example, we will describe an imaging device that uses the rotary-type vibration actuator of Example 3 to drive the lens as an optical element arranged in the lens barrel.

[0059] Figure 11(a) is a top view showing the schematic configuration of the imaging device 700. The imaging device 700 includes a camera body 730 equipped with an image sensor 710 and a power button 720. The imaging device 700 also includes a lens barrel 740 having a first lens group (not shown), a second lens group 320, a third lens group (not shown), a fourth lens group 340, and vibration-type drive devices 620 and 640. The lens barrel 740 is replaceable as an interchangeable lens, and a lens barrel 740 suitable for the subject to be photographed can be attached to the camera body 730. In the imaging device 700, the second lens group 320 and the fourth lens group 340 are driven by two vibration-type drive devices 620 and 640, respectively.

[0060] Although the detailed configuration of the vibration-type drive device 620 is not shown, the vibration-type drive device 620 has a vibration-type actuator and a drive circuit for the vibration-type actuator. The rotor 211 is positioned inside the lens barrel 740 so that its radial direction is approximately perpendicular to the optical axis. The vibration-type drive device 620 rotates the rotor 211 around the optical axis and converts the rotational output of the driven body into linear motion in the optical axis direction via gears or the like (not shown), thereby moving the second lens group 320 in the optical axis direction. The vibration-type drive device 640 has a similar configuration to the vibration-type drive device 620 and moves the fourth lens group 340 in the optical axis direction.

[0061] Figure 11(b) is a block diagram showing the schematic configuration of the imaging device 700. The first lens group 310, the second lens group 320, the third lens group 330, the fourth lens group 340, and the light intensity adjustment unit 350 are arranged at predetermined positions on the optical axis inside the lens barrel 740. Light passing through the first lens group 310 to the fourth lens group 340 and the light intensity adjustment unit 350 forms an image on the image sensor 710. The image sensor 710 converts the optical image into an electrical signal and outputs it, which is sent to the camera processing circuit 750.

[0062] The camera processing circuit 750 performs amplification, gamma correction, and other processing on the output signal from the image sensor 710. The camera processing circuit 750 is connected to the CPU 790 via the AE gate 755, and also via the AF gate 760 and the AF signal processing circuit 765. The video signal that has undergone predetermined processing in the camera processing circuit 750 is sent to the CPU 790 via the AE gate 755, the AF gate 760, and the AF signal processing circuit 765. The AF signal processing circuit 765 extracts the high-frequency components of the video signal, generates an evaluation value signal for autofocus (AF), and supplies the generated evaluation value to the CPU 790.

[0063] The CPU 790 is a control circuit that controls the overall operation of the imaging device 700, and generates control signals for exposure determination and focusing from the acquired video signal. The CPU 790 adjusts the optical axis position of the second lens group 320, the fourth lens group 340, and the light intensity adjustment unit 350 by controlling the drive of the vibration-type drive units 620, 640, and meter 630 so that the determined exposure and appropriate focus state are obtained. Under the control of the CPU 790, the vibration-type drive unit 620 moves the second lens group 320 in the optical axis direction, the vibration-type drive unit 640 moves the fourth lens group 340 in the optical axis direction, and the light intensity adjustment unit 350 is driven and controlled by the meter 630.

[0064] The optical axis position of the second lens group 320, driven by the vibration-type drive unit 620, is detected by the first linear encoder 770, and the detection result is notified to the CPU 790, which then feeds back into the operation of the vibration-type drive unit 620. Similarly, the optical axis position of the fourth lens group 340, driven by the vibration-type drive unit 640, is detected by the second linear encoder 775, and the detection result is notified to the CPU 790, which then feeds back into the operation of the vibration-type drive unit 640. The optical axis position of the light intensity adjustment unit 350 is detected by the aperture encoder 780, and the detection result is notified to the CPU 790, which then feeds back into the operation of the meter 630.

[0065] By configuring an electronic device that includes a component and one of the aforementioned vibration-type actuators for driving the component, a more compact electronic device can be provided. [Examples]

[0066] In this embodiment, a manufacturing example in which the elastic body 3 is manufactured by press molding will be explained with reference to the figures.

[0067] The configuration of the vibration actuator 1 is the same as in Figures 1 and 2, and is described in detail in Example 1, so a description in this example will be omitted.

[0068] Furthermore, the projection 3a provided on the elastic body 3 has been described in Example 1, so its explanation will be omitted here.

[0069] In this embodiment, as described above in Example 1, the outer shape of the elastic body 3 is formed by press molding and shearing.

[0070] Figure 12 is a schematic diagram illustrating the shearing process in press forming, and Figure 13 is a process diagram showing the trimming of the rectangular and extended portions of the elastic body from the sheet metal.

[0071] As shown in Figure 12(a), the workpiece 101 set inside the press die is cut off by the descending punch 103 as shown in Figure 12(b). A magnified view of the sheared area at this time is shown in Figure 12(c). The workpiece 101 forms a burr 3B, a shear surface 3A, a fracture surface 3C, and a burr 3D, and the amount of each is determined by the clearance (gap) 105 between the punch 103 and the die 104. Generally, as the clearance 105 widens, the width of the burr 3B, the area of ​​the shear surface 3A, the inclination angle of the fracture surface 3C, and the height of the burr 3D increase, and the opposite trend occurs as the clearance 105 narrows.

[0072] When forming the outer shape of the elastic body 3 using such a general shearing process, there are two methods: forming everything at once in a single shearing process, or forming it in stages over multiple processes. In this embodiment, the elastic body 3 is provided with a corner portion 33 on the tip surface 31b of the extension portion 32, as shown in Figure 13(b), in order to miniaturize the vibrating actuator. When such a corner portion is provided, it is common to form it in multiple processes to reduce damage to the mold parts, and in this embodiment as well, it is formed in multiple processes as shown in Figure 13(a) from (a1) to (a4).

[0073] Furthermore, by forming the material in multiple stages, as shown in Figure 14, the clearance 105 can be made smaller when forming the rectangular portion of the elastic body 3 (side surface 31a of the rectangular portion) and larger when forming the tip surface of the extended portion of the elastic body (tip surface 31b of the extended portion). It is also possible to change the setting value depending on the location to create a shape that suits the application.

[0074] However, by dividing the process into multiple steps, a phenomenon occurs (3D') where the elastic body 3 is strongly pressed down by other processes within the mold, crushing the burr 3D. This occurs equally in progressive dies with multiple processes and in single-stage dies with only one process.

[0075] Figure 15 shows the appearance of a crushed burr. As shown in burr 3D', the tip of the burr spreads in the direction of the columnar portion 6b of the support member 6 that loosely fits the elastic body 3, causing sharp interference between the burr 3D' and the columnar portion 6b, which may hinder the vibration of the elastic body 3. Since the elastic body 3 and the columnar portion 6b are in contact at the shear surface 3A, if the clearance 105 is set to a large amount that ensures a large fracture surface 3C during shearing, for example, the tip of the crushed burr will not protrude beyond the shear surface 3A, and the vibration will not be hindered.

[0076] However, by making the joint surface between the elastic body 3 and the piezoelectric element 4 have a larger surface area, energy can be transmitted more efficiently. Therefore, the joint surface on the elastic body 3 side needs to be finished to a flat surface with high precision through processes such as polishing. In addition, when finishing a flat surface in the polishing process, if there are burrs 3D (3D') on the polished surface, it is difficult to finish with high precision, so it is preferable to polish the side with the burrs. If the amount of clearance 105 is set to be large, the amount of burrs 3B will be large, and polishing residue is likely to occur. Therefore, for the rectangular part related to the joint surface, it is not preferable to increase the amount of clearance 105 as a method to prevent burrs 3D' from protruding beyond the shear surface 3A.

[0077] On the other hand, since the tip surface 31b of the extension 32 is not the bonding surface with the piezoelectric element 4, such measures can be taken to allow it to be used for other processes, such as positioning when joining the elastic body 3 and the piezoelectric element 4.

[0078] In this embodiment, sharp interference between the elastic body 3 and the columnar portion 6b is avoided by forming an inclined surface on the burr portion of the elastic body 3 that is in contact with the columnar portion 6b through a press molding surface stamping process.

[0079] Figure 16 is a schematic diagram illustrating the surface stamping process. It illustrates an example of forming an inclined surface on a 3D (3D') burr. Figure 16(a) shows the top dead center state in press forming, Figure 16(b) shows the state during processing, and Figure 16(c) shows the bottom dead center state.

[0080] The elastic body 3, which has a burr 3D (3D'), is pushed down by the descending die 106 and comes into contact with the material holder 107, which slides up and down by a coil spring or the like. As shown in Figure 16(b), the elastic body 3, which is compressed between the material holder 107 and the die 106, continues to descend by following the descending die 106. Then, as shown in Figure 16(c), the burr 3D (3D') is pressed against the taper 109 provided on the punch 108, and the inclination of the taper 109 is transferred, forming an inclined surface 3E.

[0081] Figure 17 is an enlarged view showing the elastic body 3 with the inclined surface 3E in contact with the columnar portion 6b.

[0082] The inclined surface 3E is inclined in a direction away from the support member 6 and toward the slider 9, starting from an intermediate position on the fracture surface 3C which is continuous with the shear surface 3A. As the inclined surface 3E is formed, the burr 3D (3D') plastically flows toward the shear surface 3A, so it is necessary to set the amount of surface hammering within the range that fits within the space created between the fracture surface 3C and the columnar portion 6b. In this embodiment, for an elastic body with a plate thickness of 0.3 mm, the inclination angle 110 was set to 45 degrees and the inclination depth 111 to 0.05 mm or less.

[0083] Furthermore, for example, if the clearance 105 in Figure 12(c) is narrower than the appropriate value, two independent shear surfaces may be generated within a single sheared surface. This is called secondary shear.

[0084] Figure 18(a) shows the punched surface of the elastic body 3 in a state of secondary shear. The secondary shear 3F is on the same plane as the shear surface 3A, and the burr 3D" on the secondary shear surface 3F is located further in the direction of the support member 6 than the burr 3D. With respect to the burr 3D", for example, by setting the inclination angle 112 to 45 degrees or less as shown in Figure 18(b), it is possible to actively induce plastic flow in the direction opposite to the columnar portion 6b. [Industrial applicability]

[0085] It can be suitably applied to optical equipment such as cameras, or to various electronic devices. [Explanation of Symbols]

[0086] 1. Vibration-type actuator 2,202 oscillators 3. Elastic body 3a Protrusion 3A shear plane 3B Dare 3C Fracture surface (first inclined surface) 3D, 3D', 3D” Bali 3E Second Inclined Surface 3F 2nd shear 31a Side of rectangular part 31b Extending part tip side 32 Extension part 33 End corner of extension part 4 Piezoelectric element 5. Foundation 6. Support Member 6a Convex part 6b Columnar part 62 Free fitting part 7. Compression spring 8 bases 9 Sliders 10 Slider holders 11 balls 12 Ball Rails 13. Adhesion jig 101 Work material 102 Scrap 103, 108 punches 104, 106 Dies 105 Clearance 107 Material holder 109 Taper 110, 112 Inclination angle 111 Slope depth 206 Ring base 208 Wave Washer 209 Pressure receiving member 211 Rotor 620, 640 Vibration-type drive unit

Claims

1. A vibratory actuator comprising an electromechanical energy conversion element and an elastic body, a vibrator having an elastic body, and a contact body in contact with the elastic body, wherein the contact body and the vibrator move relative to each other in a first direction due to the vibration of the vibrator, The elastic body has a rectangular plate portion along the first direction, a projection portion that protrudes in a second direction intersecting the first direction, and an extension portion that extends from the plate portion in the direction along the first direction. The system further includes a support member that abuts against at least one of the extension portion and the plate portion and supports the vibrator so that it can move along the second direction, A vibrating actuator is provided with a part of the elastic body having a contact surface with the support member along the second direction, and an inclined portion adjacent to the contact surface that is inclined away from the support member with respect to the contact surface.

2. The vibration actuator according to claim 1, characterized in that the support member has a protrusion that selectively supports a common node of two different vibration modes in the vibrator.

3. The vibration-type actuator according to claim 1 or 2, characterized in that a columnar portion provided on the support member is in contact with at least one of the extended portion and the plate portion of the elastic body.

4. The vibration-type actuator according to claim 3, wherein the four corners of the elastic body are loosely fitted and supported by a plurality of columnar portions.

5. The vibration actuator according to claim 1 or 2, wherein the inclined portion comprises adjacent inclined portions having different inclination angles or different curvatures, which are inclined in a direction away from the support member.

6. The vibration actuator according to claim 1 or 2, further comprising a sag portion adjacent to the contact surface on the side opposite to the side on which the inclined portion is provided with respect to the contact surface.

7. The vibration actuator according to claim 6, wherein the electromechanical energy conversion element is arranged on the surface of the plate portion that is closer to the sagging portion than the sagging portion.

8. A vibratory actuator according to claim 1 or 2, An electronic device comprising a member driven by the aforementioned vibrating actuator.

9. A vibratory actuator according to claim 1 or 2, An optical device comprising an optical element driven by the aforementioned vibrating actuator.

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