A two-degree-of-freedom uncoupled parallel motion platform

Abstract

A two-degree-of-freedom uncoupled parallel motion platform comprises a bottom platform, a base, a rectangular cymbal mechanism, an output platform, and a guide rail mechanism; the bottom platform is mounted on the base, a piezoelectric fiber sheet is attached to each side of a rectangular cymbal mechanism, and a driver is formed thereon; two drivers are arranged on the bottom platform; a central block is connected to the base platform via passive flexible hinges on all sides; an active flexible hinge mechanism is fixed to the base and connected to the passive flexible hinge; two adjacent sets of active flexible hinge mechanisms are each driven by a driver to achieve lateral or longitudinal motion of the central block; the output platform vertically presses against the central block, forming static friction therebetween; the output platform is slidably arranged on the guide rail mechanism in the lateral and longitudinal directions; the guide rail mechanism is fixed to the bottom platform. The present invention has the advantages of high frequency and low stress, easy control at high frequency, and long fatigue life under low stress.

Description

Technical Field

[0001] The present invention belongs to the field of piezoelectric precision drive, and specifically relates to a two-degree-of-freedom uncoupled parallel motion platform. It can be widely used in high-precision machining, ultra-precision displacement control and other precision positioning output fields. Background Art

[0002] Micro-motion platform systems are widely used in many precision micro-manipulation tasks, such as atomic force microscopy, photolithography, scanning probe microscopy, and nanomanipulation. To improve work quality and efficiency, micro-motion platforms increasingly require more precise actuators. Among various actuators, piezoelectric actuators use the inverse piezoelectric effect of piezoelectric materials to convert electrical energy into mechanical energy or mechanical motion. They have many advantages such as high resolution, fast response speed, and good dynamic characteristics, making them suitable for driving micro-motion platforms. In the field of micro-assembly technology, micro-motion platforms are often required to perform micron- to millimeter-level movements. Therefore, micro-motion platforms should have a large travel range. Existing micro-motion platforms have low frequency, high stress, and low motion accuracy. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides a two-degree-of-freedom uncoupled parallel motion platform, which can improve motion accuracy and has the characteristics of easy control, stable operation and flexibility.

[0004] A two-degree-of-freedom uncoupled parallel motion platform comprises a bottom platform, a base, a rectangular cymbal mechanism, an output platform and a guide rail mechanism; the bottom platform is mounted on the base, a piezoelectric fiber sheet is adhered to both sides of a rectangular cymbal mechanism and forms a driver, two drivers are arranged on the bottom platform, a central block is connected to the base platform via passive flexible hinges on all sides, an active flexible hinge mechanism is fixed to the base and connected to the passive flexible hinge, two adjacent sets of active flexible hinge mechanisms are driven by a driver respectively to achieve lateral or longitudinal movement of the central block, the output platform is vertically pressed against the central block and static friction is formed between the two, the output platform is slidably arranged on the guide rail mechanism in the lateral and longitudinal directions, and the guide rail mechanism is fixed to the bottom platform.

[0005] Furthermore, the rectangular cymbal-shaped mechanism includes a rod, four groups of flexible hinges A and a frame; four groups of flexible hinges A connected to the rod and the frame are arranged between the rod and the frame, and the four groups of flexible hinges A are evenly distributed around the rod, and piezoelectric fiber sheets are respectively attached to the relative outer sides of the frame.

[0006] Furthermore, each group of the active flexible hinge mechanism includes a fixed block, a movable block and two groups of flexible hinges B; the fixed block is fixed on the base, and two groups of flexible hinges B connected to the fixed block and the movable block are arranged between the fixed block and the movable block. The movable block is connected to the central block and the base platform respectively through passive flexible hinges, and the two sides of the cymbal-shaped mechanism rest on the fixed block and the movable block.

[0007] The beneficial effects of the present invention compared to the prior art are:

[0008] The present invention utilizes a rectangular cymbal-shaped mechanism bonded to a piezoelectric fiber sheet for output control, improving motion precision, reducing control difficulty, and minimizing errors. Flexible hinges are incorporated into both the rectangular cymbal-shaped mechanism and the base platform, enabling frictionless, noiseless, and wear-free movement of the base platform's central block, while offering high motion sensitivity, ease of control, and stable operation. Furthermore, the flexible hinge is integrally formed, requiring no assembly and offering low weight, making it suitable for use in micro-motion platforms.

[0009] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments: BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the three-dimensional structure of the two-degree-of-freedom uncoupled parallel motion platform of the present invention;

[0011] Figure 2 Exploded view of the two-degree-of-freedom uncoupled parallel motion platform of the present invention;

[0012] Figure 3 It is a structural diagram of the rectangular cymbal mechanism;

[0013] Figure 4 is a top view of the base platform;

[0014] Figure 5 is a three-dimensional diagram of the base platform;

[0015] Figure 6 is a schematic diagram of the guide rail mechanism;

[0016] Figure 7 A stereogram of the output platform;

[0017] Figure 8 A three-dimensional image of the output platform viewed from the bottom up.

[0018] Among them: 1. Bottom platform, 2. Base, 3. Rectangular cymbal mechanism, 3-1. Rod, 3-2. Flexible hinge A, 3-3. Frame, 4. Piezoelectric fiber sheet, 5. Active flexible hinge mechanism, 5-1. Fixed block, 5-2. Movable block, 5-3. Flexible hinge B, 6. Center block, 7. Guide rail mechanism, 7-1. Slide rail, 7-2. Fixed rail, 7-3. Connector, 8. Output platform, 8-1. Hollow slot, 8-2. Deformable beam, 10. Screw 2, 11. Screw 1, 14. Passive flexible hinge, b. Elastic arc sheet. DETAILED DESCRIPTION

[0019] The embodiments of the technical solution of the present invention will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0020] Example 1, as Figure 1-Figure 2 As shown, a two-degree-of-freedom uncoupled parallel motion platform comprises a bottom platform 1, a base 2, a rectangular cymbal mechanism 3, an output platform 8 and a guide rail mechanism 7; the bottom platform 1 is mounted on the base 2;

[0021] A piezoelectric fiber sheet 4 is attached to both sides of a rectangular cymbal-shaped mechanism 3 to form a driver. The two drivers are arranged on the bottom platform 1. The center block 6 is connected to the base platform 1 through passive flexible hinges 14 on all sides. The active flexible hinge mechanism 5 is fixed on the base 2 and connected to the passive flexible hinge 14. The two adjacent groups of active flexible hinge mechanisms 5 are driven by a driver respectively to realize the horizontal or vertical movement of the center block 6. The output platform 8 is vertically pressed on the center block 6 and static friction is formed between the two. The output platform 8 is slidably arranged on the guide rail mechanism 7 in the horizontal and vertical directions. The guide rail mechanism 7 is fixed on the bottom platform 1.

[0022] In this embodiment, Figure 1 As shown, the transverse direction is defined as the x-direction, and the longitudinal direction is defined as the y-direction. When voltage is applied to the piezoelectric fiber sheet 4, the cymbal mechanism 3 generates an output, and the active flexible hinge mechanism 5 deforms, driving the passive flexible hinge 14, which in turn drives the central block 6 to produce a transverse or longitudinal displacement. Under the action of static friction, the central block 6 drives the output platform 8 to move in the x-direction or y-direction. The guide rail motion mechanism 7 reduces the coupling ratio of the output platform 8 and corrects its direction of motion.

[0023] In this embodiment, two sets of active flexible hinge mechanisms 5 are adjacently positioned, one in the x-direction and the other in the y-direction, ensuring that the central block 6 can perform micro-displacement motion with two degrees of freedom. The motion platform of this embodiment utilizes the stick-slip principle, offering advantages such as high frequency and low stress, easy control at high frequencies, and a long fatigue life due to low stress.

[0024] Example 2, as Figure 3 As shown, the rectangular cymbal mechanism 3 includes a rod 3-1, four groups of flexible hinges A3-2 and a frame 3-3; four groups of flexible hinges A3-2 connected to the rod 3-1 and the frame 3-3 are arranged between the rod 3-1 and the frame 3-3, and the four groups of flexible hinges A3-2 are evenly distributed around the rod 3-1 in the circumferential direction, and piezoelectric fiber sheets 4 are respectively attached to the relative outer sides of the frame 3-3.

[0025] The specific operation of this embodiment is that when voltage is applied to the piezoelectric fiber sheet 4, it stretches, drives the frame 3-3 and drives the flexible hinge A3-2 to stretch along the length direction, and the top plate on the frame 3-3 drives the passive flexible hinge 14, thereby driving the center block 6 to move in the x or y direction.

[0026] Optionally, the flexible hinge A3-2 is a bionic flexible hinge, comprising two elastic arc-shaped pieces made in one piece, the inner arc surfaces of the two elastic arc-shaped pieces are arranged facing each other, one end of the two elastic arc-shaped pieces is fixed on the corresponding inner arc surface of the elastic arc-shaped pieces, and the other ends of the two elastic arc-shaped pieces are respectively connected to the rod 3-1 and the frame 3-3.

[0027] Example 3: Based on the above example, Figure 4 and Figure 5 As shown, this embodiment defines that each set of the active flexible hinge mechanism 5 includes a fixed block 5-1, a movable block 5-2 and two sets of flexible hinges B5-3;

[0028] The fixed block 5-1 is fixed to the base 2. Two sets of flexible hinges B5-3 are arranged between the fixed block 5-1 and the movable block 5-2, connecting the two. The movable block 5-2 is connected to the center block 6 and the base platform 1 respectively through a passive flexible hinge 14. The two sides of the cymbal-shaped mechanism 3 are against the fixed block 5-1 and the movable block 5-2. Each movable block 5-2 is connected to the bottom platform 1 and the center block 6 respectively using a passive flexible hinge 14. When voltage is applied to the piezoelectric fiber sheet 4, the cymbal-shaped mechanism 3 presses against the movable block 5-2 to generate output, and the passive flexible hinge 14 deforms, driving the center block 6 to move. By adjusting the voltage of the piezoelectric fiber sheets 4 on the two cymbal-shaped mechanisms 3, the center block 6 can move in two degrees of freedom in the x and y directions. The output platform 8 is pre-tightened on the center block 6 by screw 11, and the movement of the center block 6 can drive the output platform to move.

[0029] Further, if Figure 4 As shown, the passive flexible hinge 14 is a bionic flexible hinge comprising two integrally formed elastic arc-shaped pieces b, the inner arc surfaces of the two elastic arc-shaped pieces b facing each other, one end of each elastic arc-shaped piece b being fixed to the inner arc surface of the corresponding elastic arc-shaped piece, and the other ends of each elastic arc-shaped piece b being connected to the central block 6 and the movable block 5-2, respectively. Furthermore, the other ends of each elastic arc-shaped piece 6 are connected to the movable block 5-2 and the base platform 1, respectively.

[0030] like Figure 4 As shown, the flexible hinge B5-3 is a bionic flexible hinge, which includes two elastic arc-shaped pieces b made in one piece, the inner arc surfaces of the two elastic arc-shaped pieces b are arranged facing each other, one end of the two elastic arc-shaped pieces b is fixed on the corresponding inner arc surface of the elastic arc-shaped piece, and the other end of the two elastic arc-shaped pieces b is respectively connected to the fixed block 5-1 and the movable block 5-2.

[0031] This type of bionic flexible hinge is designed in both the rectangular cymbal mechanism 3 and the bottom platform 1, so that the movement of the central block 6 of the bottom platform 1 has many advantages such as no friction, no noise, no wear, high motion sensitivity, easy control, stable operation, etc., and this type of flexible hinge is integrally formed (cut on the base platform 1 using wire cutting), does not require assembly, is light in weight, and is suitable for use in micro-motion platforms.

[0032] Example 4: Figure 6 As shown, the guide rail mechanism 7 includes a slide rail 7-1, a fixed rail 7-2 and a connecting member 7-3;

[0033] Two slide rails 7-1 are fixed on the output platform 8 in the horizontal and vertical directions respectively, and two fixed rails 7-2 are installed on the bottom platform 1 in the horizontal and vertical directions respectively. The four slide rails 7-1 are connected to the fixed rails 7-2 through connectors 7-3 and can drive the output platform 8 to move horizontally or vertically.

[0034] During operation of this embodiment, each connecting member 7-3 is further provided with a slide rail 7-1, which is slidably mounted on the track of the fixed rail 7-2. Furthermore, the connecting member 7-3 is further provided with the track of the fixed rail 7-2. The slide rail 7-1 on the output platform 8 is slidably mounted on the track of the fixed rail 7-2. In this arrangement, the slide rail 7-1 on the output platform 8 slides on the track of the connecting member 7-3, and the slide rail 7-1 on the connecting member 7-3 slides on the track of the fixed rail 7-2, ultimately resulting in movement in the x-direction or y-direction. Preferably, each connecting member 7-3 is formed into an L-shaped plate, with the track mounted on one plate and the slide rail mounted on the other plate.

[0035] The bottom platform 1 is integrally formed by wire cutting. The bottom platform formed in this way does not require assembly, has no gaps or friction, and has high guiding precision. The rest is the same as in Examples 1-3.

[0036] Example 5: Further, based on any of the above examples 1 to 4, as Figure 7 and Figure 8As shown, the output platform 8 comprises a hollow groove 8-1 and a deformable beam 8-2. The hollow groove 8-1 is inverted, and the deformable beam 8-2 is arranged vertically within the hollow groove 8-1, forming a single connection. Screw 11 is screwed into the hollow groove 8-1 and pre-tightens the deformable beam 8-2, causing it to press against the upper surface of the center block 6. A piezoelectric fiber sheet 4 is attached to each side of the cymbal-shaped mechanism 3 or movable block 3-2 and pre-tightened to the bottom platform 1 via screw 2 10. The lower end of the deformable beam 8-2 is connected by a hollow double hinge structure. Screw 11 is screwed onto the bottom plate of the deformable beam 8-2, causing deformation and squeezing of the center block 6, generating static friction. Under the action of the piezoelectric fiber sheet 4, the two achieve synchronous movement, achieving pre-tight connection between the output platform 8 and the center block 6 of the bottom platform 1, and enabling uncoupled, high-precision motion within the constraints of the four guide rail mechanisms 7.

[0037] The present invention has been disclosed above with reference to preferred embodiments, but this is not intended to limit the present invention. Any person skilled in the art who, without departing from the scope of the technical solution of the present invention, can make slight changes or modifications to the above-disclosed structures and technical contents to produce equivalent embodiments with equivalent changes, all of which still fall within the scope of the technical solution of the present invention.

Claims

1. A two-degree-of-freedom uncoupled parallel motion platform, characterized by: The invention comprises a bottom platform (1), a base (2), a rectangular cymbal-shaped mechanism (3), an output platform (8) and a guide rail mechanism (7); the bottom platform (1) is mounted on the base (2); a piezoelectric fiber sheet (4) is attached to both sides of a rectangular cymbal-shaped mechanism (3) to form a driver, and two drivers are arranged on the bottom platform (1); the central block (6) is connected to the bottom platform (1) via a passive flexible hinge (14) on all sides; the active flexible hinge mechanism (5) is fixed on the base (2) and connected to the passive flexible hinge (14); two adjacent groups of active flexible hinge mechanisms (5) are driven by a driver respectively to realize the horizontal or vertical movement of the central block (6); the output platform (8) is vertically pressed on the central block (6) and static friction is formed between the two; the output platform (8) is slidably arranged on the guide rail mechanism (7) in the horizontal and vertical directions; the guide rail mechanism (7) is fixed on the bottom platform (1); The rectangular cymbal-shaped mechanism (3) comprises a rod (3-1), four groups of flexible hinges A (3-2) and a frame (3-3); four groups of flexible hinges A (3-2) connected to the rod (3-1) and the frame (3-3) are arranged between the rod (3-1) and the frame (3-3); the four groups of flexible hinges A (3-2) are evenly distributed around the rod (3-1) in the circumferential direction, and piezoelectric fiber sheets (4) are respectively attached to the opposite outer sides of the frame (3-3); Each set of the active flexible hinge mechanisms (5) comprises a fixed block (5-1), a movable block (5-2) and two sets of flexible hinges B (5-3); The flexible hinge B (5-3) is a bionic flexible hinge, comprising two elastic arc-shaped pieces (b) manufactured in one piece, wherein the inner arc surfaces of the two elastic arc-shaped pieces (b) are arranged facing each other, one end of the two elastic arc-shaped pieces (b) is fixed to the inner arc surface of the corresponding elastic arc-shaped piece, and the other end of the two elastic arc-shaped pieces (b) is respectively connected to the fixed block (5-1) and the movable block (5-2).

2. The two-degree-of-freedom uncoupled parallel motion platform according to claim 1, characterized in that: The fixed block (5-1) is fixed on the base (2); two groups of flexible hinges B (5-3) connected to the fixed block (5-1) and the movable block (5-2) are arranged between the fixed block (5-1) and the movable block (5-2); the movable block (5-2) is respectively connected to the central block (6) and the bottom platform (1) via a passive flexible hinge (14); and both sides of the rectangular cymbal mechanism (3) are against the fixed block (5-1) and the movable block (5-2).

3. The two-degree-of-freedom uncoupled parallel motion platform according to claim 1, characterized in that: The guide rail mechanism (7) comprises a slide rail (7-1), a fixed rail (7-2) and a connecting piece (7-3); Two slide rails (7-1) are fixed on the output platform (8) in the horizontal direction and the vertical direction respectively, and two fixed rails (7-2) are installed on the bottom platform (1) in the horizontal direction and the vertical direction respectively. The four slide rails (7-1) are connected to the fixed rails (7-2) through connecting pieces (7-3) and can drive the output platform (8) to move in the horizontal direction or the vertical direction.

4. The two-degree-of-freedom uncoupled parallel motion platform according to claim 1 or 2, characterized in that: The passive flexible hinge (14) is a bionic flexible hinge comprising two elastic arc-shaped pieces (b) formed in one piece, wherein the inner arc surfaces of the two elastic arc-shaped pieces (b) are arranged facing each other, one end of the two elastic arc-shaped pieces (b) is fixed to the inner arc surface of the corresponding elastic arc-shaped piece, and the other ends of the two elastic arc-shaped pieces (b) are respectively connected to the central block (6) and the movable block (5-2).

5. The two-degree-of-freedom uncoupled parallel motion platform according to claim 1, characterized in that: The output platform (8) comprises a hollow groove (8-1) and a deformable beam (8-2); the hollow groove (8-1) is inverted, and the deformable beam (8-2) is vertically arranged in the hollow groove (8-1) and connected as a whole; a screw (11) is screwed into the hollow groove (8-1) and pre-tightens the deformable beam (8-2), so that the deformable beam (8-2) is pressed on the upper surface of the center block (6).

6. The two-degree-of-freedom uncoupled parallel motion platform according to claim 1, characterized in that: The bottom platform (1) is integrally formed by wire cutting.

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