CN219351560U - Positioning platform - Google Patents

Abstract

The utility model provides a piezoelectric precision positioning platform. The utility model provides a precision positioning platform can include first flexible main body structure and at least one piezoelectricity driving element, first flexible main body structure includes first stiff end, middle end and first expansion end, first stiff end and middle end are connected through first flexible arm mechanism, the middle end with first expansion end is connected through second flexible arm mechanism, first flexible arm mechanism with second flexible arm mechanism is the vertical arrangement in the space, at least one piezoelectricity driving element includes first piezoelectricity driving element, first piezoelectricity driving element connects between first stiff end with the middle end. The positioning platform has compact structure and high rigidity, can realize precise positioning, and can be used in extreme environments such as ultra-high vacuum and the like.

Description

Positioning platform

Technical Field

The utility model relates to the technical field of precision positioning platforms, in particular to a compact piezoelectric precision positioning platform.

Background

The precise positioning table is an ultra-precise motion device capable of realizing micrometer-scale and even nanometer-scale positioning, and is widely applicable to scientific research, in particular to the fields of precise optics, semiconductors, medical treatment and the like. The multi-dimensional precise positioning table is generally realized by a parallel or serial structure, and the parallel structure has the characteristic of good rigidity, but has the advantages of complex structure, high processing difficulty and higher cost. The series structure has the characteristics of simple and compact structure, low cost and simple processing, but has poor overall rigidity, and is easy to cause vibration in the working process.

Disclosure of Invention

The present utility model has been made in view of the above problems. The utility model provides a compact piezoelectric precision positioning table which has high system rigidity and low cost and can realize high-precision positioning control.

According to an exemplary embodiment, a positioning platform is provided, including a first flexible main body structure and at least one piezoelectric driving element, the first flexible main body structure includes a first fixed end, a middle end and a first movable end, the first fixed end and the middle end are connected through a first flexible arm mechanism, the middle end and the first movable end are connected through a second flexible arm mechanism, the first flexible arm mechanism and the second flexible arm mechanism are vertically arranged in space, the at least one piezoelectric driving element includes a first piezoelectric driving element, and the first piezoelectric driving element is connected between the first fixed end and the middle end.

In some embodiments, the first flexible arm mechanism includes a first flexible arm and a second flexible arm arranged in parallel, the first piezoelectric drive element being disposed between the first flexible arm and the second flexible arm.

In some embodiments, the at least one piezoelectric actuation element further comprises a second piezoelectric actuation element connected between the intermediate end and the first movable end.

In some embodiments, the second flexible arm mechanism includes a third flexible arm and a fourth flexible arm arranged in parallel, the second piezoelectric driving element being disposed between the third flexible arm and the fourth flexible arm.

In some embodiments, a fifth flexible arm is disposed on the first fixed end, a sixth flexible arm is disposed on the middle end, and two ends of the first piezoelectric driving element are respectively connected with the fifth flexible arm and the sixth flexible arm.

In some embodiments, the direction of extension and retraction of the first piezoelectric drive element forms an angle θ with the first flexible arm mechanism, the θ being greater than 0 ° and less than 90 °.

In some embodiments, the flexible body structure further comprises a third flexible arm mechanism comprising a seventh flexible arm and an eighth flexible arm connected to each other, the seventh flexible arm and the eighth flexible arm being arranged vertically in space, wherein one end of the seventh flexible arm is connected to the first fixed end and one end of the eighth flexible arm is connected to the first movable end.

In some embodiments, the first flexible arm includes flexible hinges at two ends and a main body arm between the flexible hinges, the flexible hinges are plates with a thickness D and a length L, and the main body arm is a plate with a thickness D, where D > D, l+.4d.

In some embodiments, the positioning platform may further comprise a second flexible body structure located below the first flexible body structure, wherein the second flexible body structure comprises a second fixed end and a second movable end, and the at least one piezoelectric actuation element further comprises a third piezoelectric actuation element, the third piezoelectric actuation element being obliquely connected between the second fixed end and the second movable end.

In some embodiments, the second flexible body structure further comprises a fourth flexible arm mechanism through which the second fixed end and the second movable end are connected, and the fourth flexible arm mechanism comprises a ninth flexible arm and a tenth flexible arm arranged in parallel.

In some embodiments, an eleventh flexible arm is disposed on the second fixed end, a twelfth flexible arm is disposed on the second movable end, and two ends of the third piezoelectric driving element are respectively connected to the eleventh flexible arm and the twelfth flexible arm.

In some embodiments, the at least one piezoelectric driving element further comprises a fourth piezoelectric driving element, the third piezoelectric driving element and the fourth piezoelectric driving element being symmetrically disposed between the second fixed end and the second movable end.

In some embodiments, two ends of the third piezoelectric driving element and the fourth piezoelectric driving element are respectively connected with the eleventh flexible arm and the twelfth flexible arm, a first notch is arranged on the ninth flexible arm and the tenth flexible arm at a position adjacent to the second fixed end and the second movable end, a second notch is arranged on the eleventh flexible arm and the twelfth flexible arm at a position corresponding to the first notch, and the second notch cuts off the eleventh flexible arm and the twelfth flexible arm.

Through the structure and layout design of the piezoelectric driving element and the flexible main body structure, the utility model can fully utilize the space, realize the compact effect and reduce the complexity of the system, and the flexible arm is adopted to connect all the components, so that the rigidity of the system can be improved, and the nano-scale precise positioning control can be realized. The positioning platform of the utility model can also be used in various extreme environments (ultra-high vacuum, strong magnetic field, very low temperature).

The foregoing and other features and advantages of the utility model will be apparent from the following description of exemplary embodiments, as illustrated in the accompanying drawings.

Drawings

FIG. 1 shows a schematic structural view of a positioning platform according to an embodiment of the utility model;

FIGS. 2A-2B illustrate a motion schematic of a positioning stage according to an embodiment of the utility model;

FIG. 3 shows another schematic structural view of a positioning platform according to an embodiment of the utility model;

FIG. 4 shows a schematic front view of a positioning platform according to an embodiment of the utility model;

FIG. 5 shows a schematic top view of a second flexible body structure of a positioning platform according to an embodiment of the utility model;

fig. 6 shows a schematic top view of a second flexible body structure of a positioning platform according to an embodiment of the utility model.

Detailed Description

Exemplary embodiments of the present utility model are described below with reference to the accompanying drawings. In the drawings, like reference numerals generally refer to like parts. It should be understood that the dimensions and sizes of the components shown in the drawings are not necessarily drawn to scale and they may differ from those shown in the embodiments for implementation herein. Furthermore, some embodiments may incorporate any suitable combination of features from two or more drawings.

Fig. 1 shows a schematic structure of a positioning platform according to an embodiment of the utility model. As shown in fig. 1, the positioning stage system mainly comprises two parts: the flexible body structure 100 and at least one piezoelectric driving element (two piezoelectric driving elements 201 and 202 are shown in fig. 1), the piezoelectric driving elements 201 and 202 can generate telescopic deformation under the excitation of voltage, and the flexible body structure 100 amplifies the deformation to realize the precise movement of a load thereon.

The flexible main structure 100 may include a first fixed end 101, a middle end 102 and a first movable end 103, where the first fixed end 101 and the middle end 102 are connected by a first flexible arm mechanism, and the middle end 102 and the first movable end 103 are connected by a second flexible arm mechanism, and the first flexible arm mechanism and the second flexible arm mechanism are vertically arranged in space. In this way, the internal structure of the flexible main structure 100 is substantially mirror-symmetrical, so that the space can be maximally utilized, the effect of compactness is achieved, and the overall size of the precision positioning platform can be reduced. In an embodiment, the fixed end 101, the middle section 102 and the movable end 103 of the flexible main structure 100 may be integrally formed with the first flexible arm mechanism and the second flexible arm mechanism for improving the rigidity of the system.

The cross section of the fixed end 101 and the movable end 103 is basically long, and the two ends are connected through a flexible arm structure. The fixed end 101 may be provided with a threaded hole or the like to fix the positioning platform to a fixing device such as a base (not shown), and the movable end 103 may be provided with a threaded hole to cooperate with fixing/bearing a load. It will be appreciated that other fastening means may be used to secure or bear the load. The intermediate end 102 is generally square in cross-section and connects the fixed and movable ends 101, 103 and the piezoelectric driving elements 201, 202 by a flexible arm structure, which will be described in detail later.

In an example, the fixed end 101, the middle end 102, the movable end 103 and the flexible arm structure connected thereto may be made of pure titanium, titanium alloy, aluminum alloy, beryllium copper alloy, or the like, so that the positioning platform may be applied to extreme environments such as high vacuum, extremely low temperature, or strong magnetic field.

A piezoelectric driving element 201 is connected between the fixed end 101 and the intermediate end 102, and a piezoelectric driving element 202 is connected between the intermediate end 102 and the movable end 103. The piezoelectric driving elements 201, 202 may be piezoelectric ceramic stacks, which may be formed by stacking piezoelectric ceramic sheets. The piezoelectric ceramic can convert mechanical energy and electric energy into each other, has sensitive characteristics, and can generate telescopic deformation when being excited by voltage, so as to drive the movable end 103 to move. In an embodiment, the piezoelectric driving element 201 is arranged to be connected between the fixed end 101 and the intermediate end 102, and/or the intermediate end 102 and the movable end 103 in an inclined manner, so that the flexible body structure 100 can amplify the deformation of the piezoelectric ceramic stack.

Fig. 2A and 2B show a schematic motion diagram of the positioning platform according to an embodiment of the present utility model, as shown in fig. 2A, after the piezoelectric driving element 201 is energized, it will generate a telescopic deformation (adjustable by the magnitude of the applied voltage) in the direction indicated by the arrow, which will drive the movable end 103 to perform actuation in the Y-axis direction. As shown in fig. 2B, upon energizing the piezoelectric driving element 202, it will undergo a telescopic deformation in the direction indicated by the arrow, which will bring about actuation of the movable end 103 in the X-axis direction. When the piezoelectric driving element 201 and the piezoelectric driving element 202 are simultaneously electrified, the two-dimensional precise movement of the positioning platform can be realized. Wherein, as an example, the X-axis is defined herein as the extension direction of flexible arm 104, the Z-axis is positioned as the extension direction of flexible arm 110, and the Z-axis is positioned in a direction perpendicular to the X-axis, the Y-axis.

Returning to fig. 1, the first flexible arm mechanism connecting the fixed end 101 and the intermediate end 102 may include a first flexible arm 104 and a second flexible arm 105, the first flexible arm 104 and the second flexible arm 105 being arranged in parallel, and the piezoelectric driving element 201 being disposed between the first flexible arm 104 and the second flexible arm 105, i.e., the fixed end 101, the first flexible arm 104, the intermediate end 102, and the second flexible arm 105 are sequentially connected to form a hollow cavity, and the piezoelectric driving element 201 being disposed in the cavity.

To achieve a flexible connection between the fixed end 101 and the intermediate end 102, both ends of the flexible arms 104 and 105 may be provided with flexible hinges, e.g. a flexible hinge structure being a sheet metal. The flexible arms, hinges, and the like may be made of titanium, aluminum, beryllium copper, etc. as well as the fixed end 101 and the intermediate end 102 to be compatible with extreme environments. The intermediate body arm portion of the flexible arm 104 has a thickness D and the flexible hinge structure has a thickness D, where D may be greater than D, preferably D is greater than 2 times D; meanwhile, the length of the flexible hinge structure in the extending direction of the flexible arm is L, preferably L is 4 times or more d, which can improve the system rigidity.

In one embodiment, grooves are provided on opposite sides of the fixed end 101 and the intermediate end 102, flexible arms 106 are provided on the fixed end 101, flexible arms 107 are provided on the intermediate end 102, and both ends of the piezoelectric driving element 201 (e.g., a piezoelectric ceramic stack) are connected (e.g., bonded) to the flexible arms 106 and the flexible arms 107, respectively. The extending direction of the flexible arms 106 and 107 is arranged in the same direction as the extending and contracting direction of the piezoelectric driving element 201. The direction of extension and retraction of the piezoelectric driving element 201 (i.e., the direction of connection of the flexible arm 106 to the flexible arm 107) forms an angle θ with the flexible arms 104, 105, which is greater than 0 ° and less than 90 °. The acute angle setting can enable the flexible main body structure to amplify the telescopic deformation of the piezoelectric driving element 201 in a preset direction, so that the actual driving requirement is met.

In order to achieve the connection of the piezo-electric drive element 201, one end of the flexible arm 106, 107 may be provided with a flexible hinge structure, which may likewise be a sheet metal, the thickness of which is given as d, the length of the flexible hinge structure in the extension direction of the flexible arm being given as L, preferably L is 4 times d or more.

Similar to the first flexible arm structure, the second flexible arm mechanism connecting the middle end 102 and the movable end 103 may include a third flexible arm 110 and a fourth flexible arm 111, the third flexible arm 110 and the fourth flexible arm 111 being arranged in parallel, and the piezoelectric driving element 202 being disposed between the third flexible arm 110 and the fourth flexible arm 111, i.e., the middle end 102, the third flexible arm 110, the movable end 103 and the fourth flexible arm 111 are sequentially connected to form a hollow cavity, and the piezoelectric driving element 202 being disposed in the cavity. In one embodiment, the second flexible arm mechanism is spatially disposed perpendicular to the first flexible arm mechanism, i.e., the third flexible arm 110/fourth flexible arm 111 and the first flexible arm 104/second flexible arm 105 are at a 90 ° angle.

In an embodiment, grooves are disposed on opposite sides of the middle end 102 and the movable end 103, and flexible arm structures are disposed in the grooves, and two ends of the piezoelectric driving element 202 (for example, a piezoelectric ceramic stack) are respectively connected to the flexible arms, and the related connection structure and manner are similar to those of the piezoelectric driving element 201, which are not described herein. The extension and contraction direction of the piezoelectric driving element 202 and the flexible arms 110 and 111 also form an included angle θ (greater than 0 ° and less than 90 °), so that the flexible main body structure amplifies the extension and contraction deformation of the piezoelectric driving element 202 in a predetermined direction (X-axis direction), and the actual driving requirement is satisfied. It can be seen that in this embodiment the piezo- electric drive elements 201, 202 and the flexible arm structure are arranged in a square mirror symmetry, which enables maximum space utilization, making the positioning platform overall compact and robust.

In an embodiment, the flexible body structure 100 may further comprise a third flexible arm mechanism comprising a seventh flexible arm 108 and an eighth flexible arm 109 connected to each other, wherein the flexible arm 108 and the flexible arm 109 are spatially arranged vertically and parallel to the two actuation directions, respectively, i.e. the flexible arm 108 may be parallel to the first flexible arm mechanism and the flexible arm 109 may be parallel to the second flexible arm mechanism. One end of flexible arm 108 is connected to movable end 103, which may be adjacent flexible arm 110, one end of flexible arm 109 is connected to fixed end 101, and which may be adjacent flexible arm 105. The flexible arms 108 and 109 are interconnected at the abutment of the fixed end 101 and the movable end 103, which may promote the system rigidity of the positioning platform, in particular in torsional modes.

Similar to the structure of the flexible arm 104, the flexible arms 108, 109 may be provided at both ends with a flexible hinge structure, which may be a thin metal plate, having a thickness d, and a length L of the flexible hinge structure in the extending direction of the flexible arm, preferably L is 4 times d or more. The thickness D of the intermediate portion of flexible arm 104 may be greater than D, preferably D is greater than 2 times D, which may increase system rigidity.

FIG. 3 is a schematic view showing another structure of a positioning stage according to an embodiment of the present utility model, which can be added with a third actuation direction (Z-axis direction) on the basis of the two-dimensional actuation shown in FIG. 2, thereby realizing three-dimensional precision motion. As shown in fig. 3, the positioning platform may further comprise a second flexible body structure, based on the flexible body structure 100 shown in fig. 1-2, which is located below the flexible body structure 100 described above. The second flexible body structure includes a movable end 301 and a fixed end 302, wherein the movable end 301 is located below the fixed end 101 and the fixed end 302 may be located below the intermediate end 102. In one embodiment, the fixed end 301 and the movable end 302 may be integrally connected by a flexible arm structure. For example, the flexible arm structure may include a flexible arm 303 and a flexible arm 304 arranged in parallel, the structure of the flexible arms 303, 304 being similar to the structure of the flexible arms 104, 105. In an embodiment, the dimension of the flexible arm 303 in the width direction (perpendicular to the extension direction and the third actuation direction) is not less than 1/2, preferably not less than 2/3, of the extension length of the flexible body 101, 301 in the same direction, more preferably the same extension length as the flexible body 101, which may increase the system stiffness, in particular the stiffness of the torsion mode. Furthermore, both ends of the flexible arms 303, 304 may be provided with flexible hinge structures, which are similar to the structures of the flexible arms 104, 105 and will not be described here again.

In order to achieve a movement in the third actuation direction, an actuation means, such as a driving element, for example a piezo-ceramic stack, may be arranged between the movable end 301 and the fixed end 302. Fig. 4 shows a schematic front view of the positioning platform of this embodiment, in which a piezo-electric driving element 401 may be connected between the movable end 301 and the fixed end 302 at an inclination angle (i.e. the angle between the piezo-electric driving element 401 and the flexible arm 304) may be larger than 0 ° and smaller than 90 °. After the piezoelectric driving element 401 is energized, it will produce a telescopic deformation in the direction indicated by the arrow, which will drive the movable end 301 to perform actuation in the Z-axis direction, and thus drive the movable end 103 to perform Z-direction movement. The two ends of the piezoelectric driving element 401 may be connected to the movable end 301 and the fixed end 302 by flexible arm structures 305, 306, respectively, which are similar to the structures of the flexible arms 106, 107 and will not be described here again.

In an embodiment, only one piezoelectric driving element may be provided to implement the actuation in the third direction, fig. 5 shows a schematic top view of the second flexible main structure of the positioning platform according to an embodiment, as shown in fig. 5, the piezoelectric driving element 401 may be disposed in a central position of the second flexible main structure, that is, the piezoelectric driving element 401 may be connected in a central position between the movable end 301 and the fixed end 302 through a flexible arm structure, so as to improve the stability of the system.

Alternatively, two or more piezoelectric driving elements may be provided to achieve actuation in the third direction, which may increase system rigidity as well as driving force. FIG. 6 shows a schematic cross-sectional top view of a second flexible body structure of a positioning stage according to an embodiment of the utility model. As shown, two piezoceramic stacks 401 and 402 may be disposed between the movable end 301 and the fixed end 302 symmetrically, for example, the piezoceramic stack 401 is located on the head side of the movable end 301 along the length extending direction of the movable end 301, and the piezoceramic stack 402 is located on the tail side of the movable end 301, and the structure and spatial arrangement of the two piezoceramic stacks 401 and 402 may be the same to improve the system stability.

As previously described, the two ends of the piezoceramic stacks 401 and 402 may be connected to the second flexible body by flexible arms 305, 306, and the flexible arms 305, 306 may extend along the length of the movable end 301 and the fixed end 302, respectively. In one embodiment, the flexible arms 305, 306 may be truncated to increase the driving efficiency of the piezoceramic stacks 401, 402. As shown in fig. 6, opposite notches 307 (for example, 4) are provided at both ends of the flexible arm 303 and/or the flexible arm 304, that is, at positions adjacent to the movable end 301 and the fixed end 302 by wire cutting or the like, and the notches will penetrate the flexible arms 305, 306 during processing, so that notches will also be formed on the flexible arms 305, 306 at positions corresponding to the notches on the aforementioned flexible arms 303, 304, the notches will cut the flexible arms 305, 306 into three sections, and the piezoelectric ceramic stacks 401, 402 are connected to the first and last sections of the cut flexible arms 305, 306, which can improve the driving efficiency of the piezoelectric ceramic stacks 401, 402 to drive the deformation of the second flexible body.

The foregoing description of embodiments of the utility model has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many combinations, modifications, and alterations will become apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims (13)

1. The utility model provides a location platform, its characterized in that includes first flexible main body structure and at least one piezoelectricity driving element, first flexible main body structure includes first stiff end, middle end and first expansion end, first stiff end and middle end are connected through first flexible arm mechanism, the middle end with first expansion end is connected through second flexible arm mechanism, first flexible arm mechanism with second flexible arm mechanism is the vertical arrangement in the space, at least one piezoelectricity driving element includes first piezoelectricity driving element, first piezoelectricity driving element connects between the stiff end with the middle end.

2. The positioning platform of claim 1, wherein the first flexible arm mechanism comprises first and second flexible arms arranged in parallel, the first piezoelectric drive element being disposed between the first and second flexible arms.

3. The positioning platform of claim 1 or 2, wherein the at least one piezoelectric actuation element further comprises a second piezoelectric actuation element connected between the intermediate end and the first movable end.

4. A positioning platform as claimed in claim 3 wherein the second flexible arm mechanism comprises third and fourth flexible arms arranged in parallel, the second piezoelectric drive element being disposed between the third and fourth flexible arms.

5. A positioning platform according to claim 1 or 2, wherein a fifth flexible arm is provided on the first fixed end, a sixth flexible arm is provided on the intermediate end, and both ends of the first piezoelectric driving element are connected to the fifth flexible arm and the sixth flexible arm, respectively.

6. The positioning platform of claim 1 or 2, wherein the direction of extension and retraction of the first piezoelectric actuation element forms an angle θ with the first flexible arm mechanism, the θ being greater than 0 ° and less than 90 °.

7. The positioning platform of claim 1 or 2, wherein the flexible body structure further comprises a third flexible arm mechanism comprising a seventh flexible arm and an eighth flexible arm interconnected, the seventh flexible arm and the eighth flexible arm being arranged vertically in space, wherein one end of the seventh flexible arm is connected to the first fixed end and one end of the eighth flexible arm is connected to the first movable end.

8. The positioning platform of claim 2 wherein the first flexible arm comprises flexible hinges at both ends and a body arm between the flexible hinges, the flexible hinges being a sheet of thickness D and length L, the body arm being a sheet of thickness D, wherein D > D, L > 4D.

9. The positioning platform of claim 1 or 2, further comprising a second flexible body structure positioned below the first flexible body structure, wherein the second flexible body structure comprises a second fixed end and a second movable end, and wherein the at least one piezoelectric actuation element further comprises a third piezoelectric actuation element that is obliquely connected between the second fixed end and the second movable end.

10. The positioning platform of claim 9, wherein the second flexible body structure further comprises a fourth flexible arm mechanism, the second fixed end and the second movable end being connected by the fourth flexible arm mechanism, and the fourth flexible arm mechanism comprising a ninth flexible arm and a tenth flexible arm arranged in parallel.

11. The positioning platform of claim 10 wherein an eleventh flexible arm is provided on said second fixed end, a twelfth flexible arm is provided on said second movable end, and both ends of said third piezoelectric driving element are connected to said eleventh flexible arm and said twelfth flexible arm, respectively.

12. The positioning platform of claim 11 wherein said at least one piezoelectric actuation element further comprises a fourth piezoelectric actuation element, said third piezoelectric actuation element and said fourth piezoelectric actuation element being symmetrically disposed between said second fixed end and said second movable end.

13. The positioning platform of claim 12, wherein both ends of the third piezoelectric driving element and the fourth piezoelectric driving element are respectively connected to the eleventh flexible arm and the twelfth flexible arm, and wherein a first notch is provided on the ninth flexible arm and/or the tenth flexible arm at a position adjacent to the second fixed end and the second movable end, and a second notch is provided on the eleventh flexible arm and the twelfth flexible arm at a position corresponding to the first notch, and the second notch intercepts the eleventh flexible arm and the twelfth flexible arm.

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