Two-dimensional coplanar piezoelectric driving platform

Abstract

The invention discloses a two-dimensional coplanar piezoelectric driving platform, and relates to the technical field of piezoelectric motors. The device comprises a base, a mobile platform and a piezoelectric actuator, the piezoelectric actuator comprises a strip-shaped output block and two inertia stators, the strip-shaped output block is provided with a driving foot tightly attached to the lower surface of the mobile platform, and the strip-shaped output block is connected with a [-shaped frame surrounding one end of the strip-shaped output block through two flexible hinges; the inertia stator comprises a mounting seat which is connected with a W-shaped flexible hinge and a piezoelectric stack; the W-shaped flexible hinge is connected with the side wall of the [-shaped frame body, and the driving directions of the two inertia stators are perpendicular to each other and are coupled with the driving direction of the strip-shaped output block, so that the mobile platform is driven to move in any direction in a plane. The driving directions of the two inertia stators are perpendicular to each other and are coupled with the driving direction of the strip-shaped output block, so that the moving platform is driven to move in any direction in a plane, and the problem that an existing driving platform is poor in overall adaptability and driving flexibility is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of piezoelectric motors, and in particular relates to a two-dimensional coplanar piezoelectric driving platform. Background Art

[0002] Ultrasonic piezoelectric motor is a new type of driver that converts electrical energy into mechanical energy for output through the inverse piezoelectric effect of piezoelectric materials. It can be used in high-precision and high-resolution precision instruments.

[0003] For example, Chinese invention CN118017868A discloses a dual-degree-of-freedom ultrasonic micromotor, which uses six piezoelectric ceramic plates on the side of the output block to drive the output block to bend and deform, and uses a driving foot to drive the output member to move. By changing the orientation of the output member and the excitation signal, the output member can be moved in different directions, thereby achieving dual-degree-of-freedom movement through a single piezoelectric driver.

[0004] However, the driving speed and displacement accuracy of a single piezoelectric driver in the prior art are limited, and it is impossible to drive the mobile platform to achieve both high moving speed and displacement accuracy at the same time, resulting in poor overall adaptability and driving flexibility of the mobile platform. Summary of the Invention

[0005] The purpose of the present invention is to provide a two-dimensional coplanar piezoelectric drive platform, which can drive the mobile platform to move in any direction within the plane by making the driving directions of the two inertial stators perpendicular and coupled with the driving direction of the strip output block, thereby solving the problem of poor adaptability and driving flexibility of the existing mobile platform.

[0006] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0007] The present invention relates to a two-dimensional coplanar piezoelectric driving platform, which includes a base, a moving platform, and a piezoelectric driver located between the base and the moving platform. At least one set of sliding components on the base is slidably connected to the moving platform for enabling the moving platform to slide in any direction within a plane. The piezoelectric driver includes an ultrasonic stator and two inertial stators. The ultrasonic stator includes a strip-shaped output block, and a pair of driving feet that are in close contact with the lower surface of the moving platform are provided on the upper surface of the strip-shaped output block. A pair of piezoelectric ceramic sheets are covered on the other three side surfaces. Among them, flexible hinges are connected to the middle positions of both side surfaces of the strip-shaped output block, and a U-shaped frame surrounding one end of the strip-shaped output block is connected through the two flexible hinges. The inertial stator includes a mounting seat, a rectangular notch is opened in the mounting seat, a W-shaped flexible hinge is connected between two opposite inner walls of the rectangular notch, and a piezoelectric stack is fixedly connected to another inner side wall. One side of the middle of the W-shaped flexible hinge is connected to a connecting block connected to the piezoelectric stack, and the other side is connected to the side wall of the U-shaped frame. The W-shaped flexible hinges of the two inertial stators are respectively connected to adjacent side walls of the U-shaped frame, so that the driving directions of the two inertial stators are perpendicular to each other. By driving the moving platform through the ultrasonic stator and the two inertial stators respectively, the moving platform can兼备 both moving speed and displacement accuracy.

[0008] As a preferred technical solution of the present invention, the piezoelectric driver includes a mounting seat, and both inertial stators are fixedly connected to the mounting seat.

[0009] As a preferred technical solution of the present invention, the height of the U-shaped frame is greater than the height of the strip-shaped output block, and the lower surface of the U-shaped frame abuts against the upper surface of the mounting seat for leaving a gap between the strip-shaped output block and the mounting seat.

[0010] As a preferred technical solution of the present invention, the base is provided with a mounting groove adapted to the mounting seat, and a threaded hole communicating with the mounting groove is opened on the lower surface of the base, and an adjusting screw is connected. By using the adjusting screw to push up the mounting seat upward, the driving feet are in close contact with the lower surface of the moving platform.

[0011] As a preferred technical solution of the present invention, a spring is installed in the threaded hole, and the spring is located between the adjusting screw and the mounting seat, and a pre-pressure is applied to the mounting seat by the upper end of the spring.

[0012] As a preferred technical solution of the present invention, the strip-shaped output block, the flexible hinge, and the U-shaped frame are of an integral structure.

[0013] As a preferred technical solution of the present invention, the mounting seat, the W-shaped flexible hinge, and the connecting block are of an integral structure.

[0014] As a preferred technical solution of the present invention, the sliding assembly includes a slider slidably connected to the base, the slider is fixedly connected to a support block, the support block is slidably connected to the mobile platform, and the sliding direction of the mobile platform relative to the support block is perpendicular to the sliding direction of the slider.

[0015] As a preferred technical solution of the present invention, the sliding components are divided into two groups, and the sliding directions of the sliders in the two groups of sliding components are perpendicular to each other.

[0016] As a preferred technical solution of the present invention, the sliding components are divided into four groups, and the four groups of sliding components are arranged in a circular array.

[0017] The present invention has the following beneficial effects:

[0018] The present invention configures a piezoelectric driver into a bar-shaped output block and two inertial stators, utilizes a pair of driving feet on the upper surface of the bar-shaped output block to be in close contact with the lower surface of the mobile platform, and the two inertial stators are respectively connected to a U-shaped frame at one end of the bar-shaped output block. By making the driving directions of the two inertial stators perpendicular to each other, the ultrasonic stator is used to drive the mobile platform under high-frequency ultrasonic excitation to obtain a higher moving speed, thereby improving the driving efficiency.

[0019] At the same time, through the two inertial stators through low-frequency quasi-inertial drive or static direct drive, the mobile platform can obtain higher displacement accuracy, so that the mobile platform can move quickly toward the target point and can be precisely controlled to reach the target point, effectively improving the overall adaptability and driving flexibility of the mobile platform.

[0020] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 Schematic diagram of the structure of a two-dimensional coplanar piezoelectric driving platform of the present invention;

[0023] Figure 2 for Figure 1 The main view;

[0024] Figure 3 for Figure 2 Schematic diagram of the structure from an upward perspective;

[0025] Figure 4It is a schematic structural diagram of the base and the piezoelectric actuator;

[0026] Figure 5 It is a schematic structural diagram of the piezoelectric actuator, the adjusting screw and the spring;

[0027] Figure 6 It is a schematic structural diagram of the piezoelectric actuator;

[0028] Figure 7 It is Figure 6 A schematic structural diagram from the upward viewing angle;

[0029] Figure 8 It is a schematic structural diagram when there are four groups of sliding components;

[0030] Figure 9 It is a waveform diagram of the excitation signal in the resonant drive mode;

[0031] Figure 10 It is a waveform diagram of the excitation signal in the quasi-static drive mode;

[0032] [[ID=]29] Figure 11 It is a waveform diagram of the excitation signal in the static direct drive mode;

[0033] In the drawings, the list of components represented by each reference numeral is as follows:

[0034] 1 - Base, 2 - Moving platform, 3 - Ultrasonic stator, 4 - Inertial stator, 5 - Piezoelectric ceramic sheet, 6 - Piezoelectric stack, 101 - Installation groove, 102 - Adjusting screw, 103 - Spring, 104 - Slide block, 105 - Support block, 301 - Strip-shaped output block, 302 - Driving foot, 303 - Flexible hinge, 304 - C-shaped frame, 305 - Mounting seat, 401 - Mounting seat, 402 - Rectangular notch, 403 - W-shaped flexible hinge, 404 - Connecting block. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "perimeter", etc. indicating orientation or positional relationships are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0037] Embodiment 1

[0038] Please refer to Figure 1 and 2 As shown, the present invention is a two-dimensional coplanar piezoelectric drive platform, including a base 1, a moving platform 2, and a piezoelectric driver located between the base 1 and the moving platform 2. At least one set of sliding components on the base 1 is slidably connected to the moving platform 2 for enabling the moving platform 2 to slide in any direction within the plane.

[0039] Among them, the sliding component includes a slider 104 slidably connected to the base 1. The slider 104 is slidably connected to the base 1 through a guide rail. The slider 104 is fixedly connected to a support block 105, and the support block 105 is slidably connected to the moving platform 2. Moreover, the sliding direction of the moving platform 2 relative to the support block 105 is perpendicular to the sliding direction of the slider 104.

[0040] As shown in the figure, there are two sets of sliding components, and the sliding directions of the sliders 104 in the two sets of sliding components are perpendicular to each other. Or as Figure 8 shown, there are four sets of sliding components, and the four sets of sliding components are arranged in a circular array. The four sets of sliding components enable the moving platform 2 to obtain better support and are convenient for application in scenarios with larger loads.

[0041] As Figures 4 to 7 shown, the piezoelectric driver includes an ultrasonic stator 3 and two inertial stators 4. The ultrasonic stator 3 includes a strip-shaped output block 301. On the upper surface of the strip-shaped output block 301, there are a pair of driving feet 302 that are closely attached to the lower surface of the moving platform 2, and a pair of piezoelectric ceramic sheets 5 are adhered to the other three side surfaces. The strip-shaped output block 301, the flexible hinge 303, and the U-shaped frame 304 are of an integral structure. The structures of the piezoelectric driver, the driving feet 302, and the piezoelectric ceramic sheets 5, as well as the excitation method of the piezoelectric ceramic sheets 5, can refer to the prior art in the background technology.

[0042] Among them, at the middle positions of both side surfaces of the strip-shaped output block 301, flexible hinges 303 are connected, and through the two flexible hinges 303, a U-shaped frame 304 surrounding one end of the strip-shaped output block 301 is connected. The strip-shaped output block 301, the flexible hinge 303, and the U-shaped frame 304 are of an integral structure.

[0043] The inertial stator 4 includes a mounting seat 401. The mounting seat 401 can be directly connected and fixed to the base, and insulation treatment is performed between the two. The mounting seat 401 is provided with a rectangular notch 402. Between the two opposite inner walls of the rectangular notch 402, a W-shaped flexible hinge 403 is connected, and a piezoelectric stack 6 is fixedly connected to the other inner side wall.

[0044] On one side of the middle of the W-shaped flexible hinge 403, there is a connecting block 404 connected to the piezoelectric stack 6. The connecting block 404 and the W-shaped flexible hinge 403 are also connected through a flexible hinge structure. On the other side of the W-shaped flexible hinge 403, it is connected to the side wall of the C-shaped frame 304. The mounting seat 401, the W-shaped flexible hinge 403 and the connecting block 404 are of an integral structure. The W-shaped flexible hinge 403 and the C-shaped frame 304 can also be of an integral structure obtained by wire cutting, or they are fixed by welding or bonding.

[0045] Moreover, the W-shaped flexible hinges 403 of the two inertial stators 4 are respectively connected to the adjacent side walls of the C-shaped frame 304, so that the telescopic driving directions of the piezoelectric stacks 6 in the two inertial stators 4 are perpendicular to each other. By driving the moving platform 2 through the ultrasonic stator 3 and the two inertial stators 4 respectively, the moving platform 2 has both moving speed and displacement accuracy at the same time.

[0046] As Figure 6 and 7 shown, the telescopic driving direction of the piezoelectric stack 6 in one of the inertial stators 4 is parallel to the length direction of the bar-shaped output block 301, and the telescopic driving direction of the piezoelectric stack 6 in the other inertial stator 4 is perpendicular to the length direction of the bar-shaped output block 301.

[0047] Specifically, the driving methods include:

[0048] Resonant driving mode: As Figure 9 shown, by applying an excitation signal to the piezoelectric ceramic sheet 5 of the ultrasonic stator 3, the moving platform 2 is driven by the two driving feet 302 on the bar-shaped output block 301. Thus, under high-frequency ultrasonic excitation, the ultrasonic stator 3 drives the moving platform 2 to move quickly, enabling the moving platform 2 to perform long-distance rapid positioning.

[0049] Quasi-static driving mode: As Figure 10 shown, by applying a sawtooth wave excitation signal to the piezoelectric stacks 6 of the two inertial stators 4, two non-symmetric mechanical vibrations in orthogonal directions are generated in the two inertial stators 4. Through the stick-slip friction coupling of the driving feet 302, the driving of the moving platform 2 has a higher-precision displacement compared with the resonant driving mode, realizing precise control of the displacement of the moving platform 2.

[0050] Static direct driving mode: As Figure 11 shown, that is, an excitation signal with a certain voltage is applied to the inertial stator 4, thereby driving the moving platform 2 for precise positioning.

[0051] In the actual use process, the three modes can be combined. After the system determines the target point and path planning that the moving platform 2 needs to reach, first, through the resonant driving mode, the ultrasonic stator 3 is used to drive the moving platform 2 for long-distance high-speed positioning.

[0052] Secondly, after reaching a certain distance, switch to the quasi-static driving mode and use the inertial stator 4 to drive the moving platform 2, so as to achieve a stable transition of the moving platform 2 from high-speed movement to low-speed movement, and short-distance precise displacement control can be performed.

[0053] Finally, in the static direct drive mode, use the inertial stator 4 to drive the moving platform 2 for high-precision positioning, and the displacement accuracy is 1 nanometer. Thus, through the cross-scale cooperation of the ultrasonic stator 3 and the two inertial stators 4, and through multi-mode driving methods, the piezoelectric driving platform of the present application can reach a stroke of 400 mm × 400 mm, a speed not lower than 300 mm / s, and a resolution of 1 nm, so that the moving platform has the ability of both high-speed movement and high displacement accuracy at the same time.

[0054] Among them, the strip output block 301 can not only drive the moving platform 2 to move alone, but also, when synchronously driving with the inertial stator 4, by controlling the duty cycle or phase difference of the excitation signals of the two, the moving direction of the moving platform 2 can be flexibly controlled, greatly improving the overall adaptability and driving flexibility of the driving platform.

[0055] Embodiment 2

[0056] Based on Embodiment 1, as Figures 3-5 shown, the piezoelectric actuator includes a mounting base 305, and the mounting bases 401 of the two inertial stators 4 are both fixedly connected to the mounting base 305 by screws. The height of the C-shaped frame 304 is greater than the height of the strip output block 301, and the lower surface of the C-shaped frame 304 abuts against the upper surface of the mounting base 305, so as to leave a gap between the strip output block 301 and the mounting base 305 to avoid affecting the deformation of the strip output block 301.

[0057] Moreover, the mounting positions of the mounting base 401 and the mounting base 305 have bosses, so that the W-shaped flexible hinge 403 and the piezoelectric stack 6 in the inertial stator 4 also do not contact the surface of the mounting base 305, thereby reducing the resistance suffered by the W-shaped flexible hinge 403 and the piezoelectric stack 6 during the driving process and avoiding wear with the surface of the mounting base 305.

[0058] At the same time, the base 1 is provided with a mounting groove 101 adapted to the mounting base 305, and the mounting base 305 is installed inside the mounting groove 101. And the lower surface of the base 1 is provided with a threaded hole communicating with the mounting groove 101, and an adjusting screw 102 is connected through the threaded hole, so as to push the mounting base 305 upward by the adjusting screw 102 to make the driving foot 302 closely adhere to the lower surface of the moving platform 2.

[0059] As a more preferred embodiment, a spring 103 is installed in the threaded hole, and the spring 103 is located between the adjusting screw 102 and the mounting seat 305. The upper end of the adjusting screw 102 pushes the spring 103 upward, and the upper end of the spring 103 pushes the lower surface of the mounting seat 305. Pre-pressure is applied to the mounting seat 305 through the upper end of the spring 103, so that the driving foot 302 can maintain close contact with the lower surface of the mobile platform 2.

[0060] By screwing the adjusting screw 102 to move axially, the compression degree of the spring 103 is adjusted, that is, the extrusion force between the driving foot 302 and the surface of the mobile platform 2 is adjusted, so that the driving foot 302 and the mobile platform 2 can maintain good contact, and avoid the situation where the extrusion force between the two is too large, resulting in excessive wear or affecting the driving effect, so that the overall reliability and stability of use are effectively improved.

[0061] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0062] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A two-dimensional coplanar piezoelectric drive platform, comprising a base (1), a moving platform (2), and a piezoelectric driver located between the base (1) and the moving platform (2), characterized in that: At least one set of sliding components of the base (1) is slidably connected to the moving platform (2) for enabling the moving platform (2) to slide in any direction within a plane; The piezoelectric driver includes an ultrasonic stator (3) and two inertial stators (4). The ultrasonic stator (3) includes a strip-shaped output block (301). On the upper surface of the strip-shaped output block (301), there are a pair of driving feet (302) closely attached to the lower surface of the moving platform (2), and a pair of piezoelectric ceramic sheets (5) are covered on the other three side surfaces; Among them, at the middle positions of both side surfaces of the strip-shaped output block (301), flexible hinges (303) are connected, and through the two flexible hinges (303), a U-shaped frame body (304) surrounding one end of the strip-shaped output block (301) is connected; The inertial stator (4) includes a mounting seat (401). The mounting seat (401) is provided with a rectangular notch (402). Between the two opposite inner walls of the rectangular notch (402), a W-shaped flexible hinge (403) is connected, and on the other inner side wall, a piezoelectric stack (6) is fixedly connected; One side of the middle part of the W-shaped flexible hinge (403) is connected with a connection block (404) connected to the piezoelectric stack (6), and the other side is connected to the side wall of the U-shaped frame body (304). The W-shaped flexible hinges (403) of the two inertial stators (4) are respectively connected to the adjacent side walls of the U-shaped frame body (304), so that the driving directions of the two inertial stators (4) are perpendicular. By driving the moving platform (2) through the ultrasonic stator (3) and the two inertial stators (4) respectively, the moving platform (2) simultaneously has both moving speed and displacement accuracy.

2. A two-dimensional coplanar piezoelectric driving platform according to claim 1, characterized in that: The piezoelectric driver includes a mounting seat (305), and the two inertial stators (4) are both connected and fixed to the mounting seat (305).

3. The two-dimensional coplanar piezoelectric driving platform according to claim 2, characterized in that: The height of the U-shaped frame body (304) is greater than the height of the strip-shaped output block (301), and the lower surface of the U-shaped frame body (304) abuts against the upper surface of the mounting seat (305) for leaving a gap between the strip-shaped output block (301) and the mounting seat (305).

4. The two-dimensional coplanar piezoelectric driving platform according to claim 3, characterized in that: The base (1) is provided with a mounting groove (101) adapted to the mounting seat (305), and a threaded hole communicating with the mounting groove (101) is opened on the lower surface of the base (1), and an adjusting screw (102) is connected for pushing the mounting seat (305) upward through the adjusting screw (102) so that the driving feet (302) are closely attached to the lower surface of the moving platform (2).

5. The two-dimensional coplanar piezoelectric driving platform according to claim 4, characterized in that: A spring (103) is installed in the threaded hole, and the spring (103) is located between the adjusting screw (102) and the mounting seat (305), and a pre-pressure is applied to the mounting seat (305) by the upper end of the spring (103).

6. A two-dimensional coplanar piezoelectric driving platform according to claim 1 or 5, characterized in that: The strip-shaped output block (301) and the flexible hinge (303) and the U-shaped frame body (304) are of an integral structure.

7. The two-dimensional coplanar piezoelectric driving platform according to claim 6, characterized in that: The mounting seat (401) and the W-shaped flexible hinge (403) and the connection block (404) are of an integral structure.

8. A two-dimensional coplanar piezoelectric driving platform according to claim 1, 5 or 7, characterized in that: The sliding assembly comprises a slider (104) slidably connected to the base (1); the slider (104) is fixedly connected to a support block (105); the support block (105) is slidably connected to the mobile platform (2); and the sliding direction of the mobile platform (2) relative to the support block (105) is perpendicular to the sliding direction of the slider (104).

9. The two-dimensional coplanar piezoelectric driving platform according to claim 8, characterized in that: The sliding components are divided into two groups, and the sliding directions of the sliders (104) in the two groups of sliding components are perpendicular to each other.

10. The two-dimensional coplanar piezoelectric driving platform according to claim 8, characterized in that: There are four groups of sliding components, and the four groups of sliding components are arranged in a circular array.

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