Piezoelectric actuator

Abstract

The utility model discloses a piezoelectric actuator, which comprises a piezoelectric support, a piezoelectric element and a piezoelectric element, the piezoelectric body is contained in the piezoelectric support, the two sides of the piezoelectric body are each provided with a first pole piece and a second pole piece, and the piezoelectric body moves according to driving voltage applied to the first pole pieces and the second pole pieces; and the buffer body is connected between the piezoelectric bracket and the piezoelectric body. According to the piezoelectric actuator, the piezoelectric actuator is simple in structure and small in size, miniaturization of electronic equipment is facilitated, traction force during piezoelectric vibration is effectively reduced through the buffer body, mechanical loss is reduced, and driving efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of motion control, and further relates to a piezoelectric driver. Background Art

[0002] In some electronic terminals, it's often necessary to animate certain components to achieve specific functions. Traditional drive structures utilize electric motors, which have essential components such as magnetic poles, armatures, and speed reducers. This results in a complex and bulky drive mechanism, hindering the miniaturization of electronic devices. Utility Model Content

[0003] In view of the above technical problems, the purpose of the present invention is to provide a piezoelectric driver that can solve the problems of complex structure and large size of the driving mechanism.

[0004] In order to achieve the above-mentioned object, the piezoelectric driver provided by the present invention includes:

[0005] Piezoelectric support;

[0006] a piezoelectric body, the piezoelectric body being accommodated in the piezoelectric support, a first pole piece and a second pole piece being provided on both sides of the piezoelectric body, and the piezoelectric body being displaced according to a driving voltage applied to the first pole piece and the second pole piece;

[0007] The buffer body is connected between the piezoelectric support and the piezoelectric body.

[0008] In some embodiments, the piezoelectric body is a structure in which multiple dielectrics and multiple internal electrodes are stacked, and the internal electrodes include a first electrode and a second electrode arranged in layers, the first electrode includes a long electrode and two short electrodes, the long electrode has two electrode parts, the electrode parts and the short electrodes are electrically connected to the two first pole pieces respectively, and the second electrode is electrically connected to the second pole piece.

[0009] In some embodiments, the piezoelectric driver further includes a friction body and a rotating disk, wherein the friction body is connected to one side of the piezoelectric body, the friction body is frictionally connected to the rotating disk, and the rotating disk is transmission-connected to the shaft body via a turntable bearing.

[0010] In some embodiments, the buffer body has a "U"-shaped structure.

[0011] In some embodiments, the first pole piece and the second pole piece are both electrically connected to a reed spring, and the reed spring is connected to an electrical connector.

[0012] In some embodiments, the thickness of the leaf spring is 0.03-0.2 mm.

[0013] In some embodiments, the piezoelectric driver further includes a cover and an elastic body, wherein the cover is located on a side of the piezoelectric support facing away from the rotating disk, and one end of the elastic body is connected to the cover, and the other end is connected to the piezoelectric body.

[0014] In some embodiments, the piezoelectric driver includes a plurality of elastic bodies, and the plurality of elastic bodies are symmetrically arranged between the cover and the piezoelectric body.

[0015] In some embodiments, the piezoelectric support is threadedly connected to the cover.

[0016] In some embodiments, the friction body is a sheet structure, which includes a connecting surface and a friction surface that are opposite to each other. The connecting surface is fixedly connected to the piezoelectric body, and the friction surface is in friction contact with the rotating disk.

[0017] Compared with the prior art, the piezoelectric driver provided by the present invention has the following beneficial effects:

[0018] The piezoelectric driver proposed in the utility model has a simple structure and a small size, which helps to achieve miniaturization of electronic equipment. The buffer body effectively reduces the traction force during piezoelectric vibration, reduces mechanical loss, and improves driving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The preferred embodiments will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0020] Figure 1 It is a structural schematic diagram of the micro pan-tilt projector in the preferred embodiment of the present utility model in the assembled state.

[0021] Figure 2 yes Figure 1 Schematic top view of .

[0022] Figure 3 yes Figure 1 Schematic diagram of the structure of the part where the medium voltage electric drive is located.

[0023] Figure 4 yes Figure 1 A schematic structural diagram of the piezoelectric body. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without inventive work.

[0025] refer to Figure 1 and Figure 4 According to a preferred embodiment of the present invention, an electronic device includes a housing 1, a projection module 12 and a control unit for controlling the projection module 12. The electronic device can use the projection module 12 to project an image. The electronic device can be a projector, a projection-type display device, etc. The implementation method of this application is described using the electronic device being a projector as an example. It should be noted that the specific form of the electronic device is not limited to a projector, but can also be other electronic devices, which is not limited here.

[0026] The control unit is electrically connected to the projection module 12 to control the projection module 12. The control unit includes user-operated control buttons or a touch display, which drives the projection module 12 according to the user's operation. The control unit can also be operated by a user terminal and is communicatively connected to the user terminal. The user terminal is used to operate the electronic device and can communicate with the electronic device via communication methods such as WiFi, Bluetooth, and NFC. The user terminal can be a portable terminal such as a smartphone, tablet terminal, or wearable terminal, or a fixed terminal such as a personal computer, without limitation.

[0027] The housing 1 may be the outer shell of an electronic device and is used to house the projection module 12, providing waterproof, dustproof, and drop-proof protection for the projection module 12. A through hole may be provided on the front or back of the housing 1. When the projection module 12 is housed in the housing 1, the light exit hole of the projection module 12 is aligned with the through hole.

[0028] The projection module 12 includes a lens barrel and a light source, a display reflector and a lens group housed in the lens barrel in sequence. The light source is used to emit light, the display reflector is used to process the light from the light source and reflect the light with image information toward the lens group, and the lens group is used to diffuse the light from the display reflector to increase the projection area of ​​the image information.

[0029] The projection module 12 is applied with a piezoelectric driver 13 . The piezoelectric driver 13 is disposed in the housing 1 and is coupled to the projection module 1 via a transmission assembly to drive the projection module 12 to rotate so as to adjust the projection angle of the projection module 12 .

[0030] For ease of understanding and description, in the embodiment of the present invention, the height direction of the housing 1 is taken as the Z direction, and any orthogonal axis perpendicular to the Z direction is taken as the X direction and the Y direction.

[0031] The piezoelectric driver 13 includes a piezoelectric support 3, a piezoelectric element 2, and a friction element 5. The piezoelectric support 3 is mounted within the housing 1 and extends in the X direction. It includes a mounting cavity with two open ends, housing the piezoelectric element 2. The friction element 5 is connected to one end of the piezoelectric element 2. When energized, the piezoelectric element 2 deforms, driving the friction element 5 to move relative to the piezoelectric support 3 in the Y direction.

[0032] The piezoelectric body 2 is a structure in which a plurality of dielectrics and a plurality of internal electrodes are stacked. As an example, Figure 4 As shown, the first dielectric 231 is configured in the top layer, a first electrode is arranged between the first dielectric 231 and the second dielectric 232 of the lower layer, and a second electrode 243 is arranged between the second dielectric 232 and the third dielectric 233 of the lower layer. The first electrode and the second electrode 243 are alternately stacked through the dielectric, thereby obtaining a piezoelectric body 2.

[0033] The first electrode includes a long electrode 241 and two short electrodes 242. The long electrode 241 has two electrode portions 2411. The two electrode portions 2411 are staggered along the width direction of the piezoelectric body 2 and are located on both sides of the length direction of the piezoelectric body 2. The two short electrodes 242 are respectively spaced apart from the two electrode portions 2411. The electrode portion 2411, the short electrode 242 and the second electrode 243 all have an electrode lead-out portion 244.

[0034] like Figure 2 and Figure 3 As shown, two first pole pieces 25 are alternately connected on both sides of the width direction of the piezoelectric body 2, and a second pole piece 26 is located between the two first pole pieces 25. The electrode portion 2411 and the short electrode 242 are electrically connected to the two first pole pieces 25 respectively through the electrode lead-out portion 244 thereon, and the second electrode 243 is electrically connected to the second pole piece 26 through the electrode lead-out portion 244 thereon.

[0035] The first electrode, second electrode 243, first pole piece 25, and second pole piece 26 are made of a low-rigidity conductive material, such as a thin film of metal such as gold or silver, graphite powder, or a mixture of silicone oil and graphite. The dielectric is made of a piezoelectric material that deforms when energized, such as quartz crystal, aluminum nitride, zinc oxide, lead zirconate titanate, barium titanate, lithium gallate, lithium germanate, or titanium germanate. When a driving voltage is applied to the first pole piece 25 and the second pole piece 26, the dielectric expands or contracts, driving the friction body 5 to move in the Y direction.

[0036] See again Figure 2The piezoelectric driver 13 also includes a buffer body 4, which is disposed between the piezoelectric element 2 and the piezoelectric support 3. The buffer body 4 is made of an insulating and elastic buffer material, such as polyurethane foam, polyethylene foam, ethylene-vinyl acetate copolymer, etc., and is used to relieve stress and reduce noise when the piezoelectric element 2 vibrates. The buffer body 4 can be integrally formed or split. For example, the buffer body 4 is tightly attached to the mounting cavity of the piezoelectric support 3, forming an overall "U"-shaped structure.

[0037] like Figure 2 As shown, the transmission assembly includes a rotating disk 6 and a shaft 8. The rotating disk 6 has an annular cross-section. The rotating disk 6 is in friction contact with the friction body 5. The shaft 8 is installed on the lens barrel of the projection module 12. The shaft 8 is connected to the rotating disk 6 through a turntable bearing 7.

[0038] When the piezoelectric element 2 drives the friction element 5 to move in the Y direction, the friction element 5 transmits a force to the rotating disk 6, causing the rotating disk 6 to rotate relative to the housing 1. The rotating disk 6 then drives the shaft 8 to rotate via the turntable bearing 7. Because the shaft 8 is mounted on the lens barrel of the projection module 12, the projection module 12 also rotates relative to the housing 1, thereby adjusting the projection angle of the projection module 12.

[0039] The friction body 5 can be a sheet structure, comprising a connecting surface and a friction surface positioned opposite each other. The connecting surface is fixedly connected to the piezoelectric body 2, and the friction surface is in frictional contact with the rotating disk 6. The friction surface has a relatively high roughness, and a large friction force can be generated between the friction body 5 and the rotating disk 6, allowing the rotating disk 6 to rotate under the drive of the friction body 5.

[0040] The friction body 5 is made of wear-resistant material, for example, the material is selected from high hardness wear-resistant ceramic materials such as aluminum oxide, zirconium oxide, silicon carbide ceramics, or high wear-resistant metal materials, carbon fiber materials, or composite materials of ceramics, metal particles and polymers, etc., which are not limited here.

[0041] The friction body 5 and the piezoelectric body 2 can be integrally connected by bonding, snapping, nesting, or fastener connection, without limitation. As an example, the connection surface of the friction body 5 can be fixed to the piezoelectric body 2 by bonding. The connection surface of the friction body 5 can be polished so that the connection surface is completely attached to the piezoelectric body 2, and the connection surface and the piezoelectric body 2 have strong bonding strength, ensuring good assembly characteristics between the friction body 5 and the piezoelectric body 2.

[0042] A cover 9 is also provided in the shell 1, and the cover 9 is connected to the side of the piezoelectric support 3 facing away from the rotating disk 6. An elastomer 11 is provided in the cover 9, and the elastomer 11 is telescopically arranged between the cover 9 and the piezoelectric body 2, for providing a pre-tightening force to the friction body 5 toward the rotating disk 6, ensuring that the friction body 5 and the rotating disk 6 maintain friction contact.

[0043] One end of the elastic body 11 is connected to the cover 9, and the other end is connected to the piezoelectric body 2. In order to improve the reliability of the connection between the elastic body 11 and the piezoelectric body 2, a gasket 10 is connected to the end of the piezoelectric body 2 facing away from the rotating disk 6. The elastic body 11 is retractably arranged between the gasket 10 and the cover 9. The gasket 10 can also be a sheet structure and can be connected to the piezoelectric body 2 as a whole by bonding, snapping, nesting, or fastener connection, which is not limited here.

[0044] The material of the elastomer 11 can be an organic material, such as a polymer resin material, or a material having a certain degree of flexibility. The elastomer 11 can also be a hollow coil spring made of carbon steel or a flat serrated structure, without limitation. The number of elastomers 11 can be one or more. It is understood that symmetrically arranged elastomers 11 can better control the balance of the piezoelectric body 2.

[0045] The piezoelectric support 3 and the cover 9 can be an integrally formed structure or a detachable structure, which is not particularly limited in the present embodiment. For example, the cover 9 has a hollow portion, which can be a groove or a hole structure, and a threaded hole is provided in the hollow portion. The threaded hole extends along the X direction, and the piezoelectric support 3 is provided with an external thread on the outer periphery, so that the piezoelectric support 3 is threadedly connected to the cover 9. By rotating the piezoelectric support 3, the piezoelectric support 3 can be moved along the X direction to adjust the preload force between the friction body 5 and the rotating disk 6, ensuring close contact between the friction body 5 and the rotating disk 6.

[0046] The piezoelectric driver 13 also includes a control motherboard, which is connected to the first and second pole pieces 25, 26 via connecting wires (e.g., leads). In some embodiments, a reed spring 14 is connected to the first and second pole pieces 25, 26. The reed spring 14 can be integrally connected to the first and second pole pieces 25, 26 by laser welding, heat-sink welding, or other methods. The reed spring 14 is connected to the control motherboard via leads. The control motherboard can apply an AC excitation signal to the first and second pole pieces 25, 26, thereby causing the piezoelectric element 2 to bend or contract.

[0047] The leaf spring 14 in the embodiment of the present invention not only electrically connects the electrode and the control mainboard but also has elastic properties, allowing it to release the traction force of the piezoelectric body 2 through elastic deformation. The thinner the leaf spring 14, the more significant the traction release effect, and it also helps to achieve a miniaturized design of the piezoelectric driver 13. The thickness of the leaf spring 14 is preferably 0.03-0.2 mm. It is understood that the leaf spring 14 can also adopt a thinner or thicker structural design, which is not limited here.

[0048] In addition, the piezoelectric driver 13 does not need to be equipped with a control motherboard. The reed spring 14 can be directly electrically connected to the control part of the electronic device through an electrical connector (lead or pin, etc.), that is, the piezoelectric driver 13 can be controlled by the control part of the electronic device.

[0049] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A piezoelectric actuator, characterized in that: include: Piezoelectric support; a piezoelectric body, the piezoelectric body being accommodated in the piezoelectric support, a first pole piece and a second pole piece being provided on both sides of the piezoelectric body, and the piezoelectric body being displaced according to a driving voltage applied to the first pole piece and the second pole piece; a buffer body connected between the piezoelectric support and the piezoelectric body; The piezoelectric body is a structure in which multiple dielectrics and multiple internal electrodes are stacked. The internal electrodes include a first electrode and a second electrode arranged in layers. The first electrode includes a long electrode and two short electrodes. The long electrode has two electrode parts. The electrode parts and the short electrodes are electrically connected to the two first pole pieces respectively. The second electrode is electrically connected to the second pole piece.

2. The piezoelectric actuator according to claim 1, wherein: The piezoelectric driver further includes a friction body and a rotating disk. The friction body is connected to one side of the piezoelectric body. The friction body is frictionally connected to the rotating disk. The rotating disk is transmission-connected to the shaft body via a turntable bearing.

3. The piezoelectric actuator according to claim 1, wherein: The buffer body has a "U"-shaped structure.

4. The piezoelectric actuator according to claim 1, wherein: The first pole piece and the second pole piece are both electrically connected to a reed spring, and the reed spring is connected to an electrical connector.

5. The piezoelectric actuator according to claim 4, wherein: The thickness of the leaf spring is 0.03-0.2 mm.

6. The piezoelectric actuator according to claim 1, wherein: The piezoelectric driver further comprises a cover and an elastic body. The cover is located on the side of the piezoelectric support facing away from the rotating disk. One end of the elastic body is connected to the cover, and the other end is connected to the piezoelectric body.

7. The piezoelectric actuator according to claim 6, wherein: The piezoelectric driver includes a plurality of elastic bodies, and the plurality of elastic bodies are symmetrically arranged between the cover and the piezoelectric body.

8. The piezoelectric actuator according to claim 7, wherein: The piezoelectric support is threadedly connected to the cover.

9. The piezoelectric actuator according to claim 2, wherein: The friction body is in a sheet structure, and includes a connecting surface and a friction surface that are opposite to each other. The connecting surface is fixedly connected to the piezoelectric element, and the friction surface is in friction contact with the rotating disk.

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