A four-stable two-dimensional micro-motion platform

Abstract

The present invention provides a four-stable two-dimensional micro-motion platform, which can solve the problem that the existing micro-motion platforms cannot stay at multiple stable positions without external force input. It includes a base, a moving platform, stacked piezoelectric actuators, and a three-section fully compliant bistable mechanism. A set of transmission beam assemblies are respectively connected to both ends of the moving platform in the X-axis direction and both ends in the Y-axis direction. Each set of transmission beam assemblies is respectively connected to the base through a set of three-section fully compliant bistable mechanisms. The distances a from the two sets of three-section fully compliant bistable mechanisms located on the same axis to the center point O of the moving platform are the same and the two sets of three-section fully compliant bistable mechanisms are parallel to each other. Each set of fully compliant bistable mechanisms is respectively arranged opposite to a stacked piezoelectric actuator, and the stacked piezoelectric actuator is fixedly installed on the base.

Description

Technical Field

[0001] The present invention relates to the field of micro-motion platform structures, and particularly to a four-stable-state two-dimensional micro-motion platform. Background Art

[0002] A micro-motion platform is a micro-positioning mechanism that transmits force and displacement through the elastic deformation of a flexible structure. Since it is integrally processed, it does not require assembly and there are no gaps, friction, or wear. In addition, since it is usually driven by a piezoelectric actuator, the micro-motion platform has a high displacement resolution, large stiffness, small volume, and strong load-bearing capacity, and is widely used in micro-nano positioning systems. Currently, in precision mechanical assembly or positioning, it is usually necessary for the micro-motion platform to stay at multiple points in order to complete corresponding operations. Designing the required operation points as stable positions can enable the platform to stay at the corresponding points without the need for additional force (or energy); at the same time, the closer the operation point is to the stable position, the less energy is required to move to that point; and a micro-motion platform with multiple stable positions can also save the energy required for work to a certain extent. Chinese invention patents with publication numbers CN103225728B and CN105551836B respectively disclose a two-dimensional parallel micro-motion platform driven by piezoelectric ceramics and a two-dimensional micro-motion platform device. Although they both have high positioning accuracy, such mechanisms cannot achieve staying at multiple stable positions without external force input. Summary of the Invention

[0003] In view of the above problems, the present invention provides a four-stable-state two-dimensional micro-motion platform, which can solve the problem that the existing micro-motion platform cannot achieve staying at multiple stable positions without external force input.

[0004] The technical solution is as follows: A four-stable-state two-dimensional micro-motion platform includes a base, a moving platform, and a stacked piezoelectric actuator. It is characterized in that: it further includes a three-section fully compliant bistable mechanism. At both ends of the X-axis and both ends of the Y-axis of the moving platform, a set of transmission beam assemblies are respectively connected. Each set of transmission beam assemblies is respectively connected to the base through a set of the three-section fully compliant bistable mechanisms. The distances a from the two sets of three-section fully compliant bistable mechanisms located on the same axis to the center point O of the moving platform are the same and the two sets of three-section fully compliant bistable mechanisms are parallel to each other. Each set of fully compliant bistable mechanisms is respectively arranged opposite to a stacked piezoelectric actuator, and the stacked piezoelectric actuator is fixedly installed on the base.

[0005] Further, each set of transmission beam assemblies includes two parallel transmission beams. Among them, the two sets of transmission beam assemblies located at both ends of the X-axis of the moving platform are both arranged parallel to the X-axis, and the two sets of transmission beam assemblies located at both ends of the Y-axis of the moving platform are both arranged parallel to the Y-axis.

[0006] Further, both ends of each of the transmission beams are respectively connected to the moving platform and the three-stage fully compliant bistable mechanism through a shallow-cut elliptical flexible hinge.

[0007] Further, each set of the three-stage fully compliant bistable mechanisms respectively includes a shuttle and four sets of connecting beam assemblies. The side surface of the shuttle facing the moving platform is the moving-platform connection surface. The moving-platform connection surface is connected to the moving platform through the set of transmission beam assemblies. Two opposite end faces of the shuttle that face the base and are adjacent to the moving-platform connection surface are respectively connected to the base through two sets of the connecting beam assemblies.

[0008] Further, each set of the connecting beam assemblies respectively includes a rigid beam and two flexible beams. The two flexible beams are respectively a shuttle-end flexible beam and a base-end flexible beam. Axial two ends of the rigid beam are respectively connected to one ends of the shuttle-end flexible beam and the base-end flexible beam. And the other end of the shuttle-end flexible beam is connected to the shuttle, and the other end of the base-end flexible beam is connected to the base.

[0009] Further, the connection angle formed by the shuttle-end flexible beam and the shuttle is not a right angle.

[0010] Further, the base is of a cuboid structure, and a set of opposite faces of the base are square faces.

[0011] Further, through hollow slots in a cross shape are formed on a pair of opposite square faces of the base. The moving platform is located within the cross-shaped hollow slots. Piezoelectric stack actuators are respectively fixedly installed at the central positions of the four slot bottom surfaces of the cross-shaped hollow slots.

[0012] Further, the moving platform is of a cuboid structure and a pair of opposite faces thereof are square faces. The pair of square faces of the moving platform are arranged parallel to the pair of square faces of the base. The base-end flexible beams in the three-stage fully compliant bistable mechanisms respectively connected to the two ends in the X axis direction and the two ends in the Y axis direction of the cuboid-structured moving platform are fixedly connected to the side slot walls of the cross-shaped hollow slots of the base.

[0013] Further, the base, the moving platform, the three-stage fully compliant bistable mechanism, the shallow-cut elliptical flexible hinge, and the transmission beam are of an integral structure.

[0014] The beneficial effects of the present invention are as follows: The base and the moving platform are connected by four groups of three-section fully compliant bistable mechanisms at both ends in the X-axis direction and both ends in the Y-axis direction. And the distances from the two groups of three-section fully compliant bistable mechanisms located on the same axis to the center point of the moving platform are the same and the two groups of three-section fully compliant bistable mechanisms are parallel to each other. Thus, the moving platform can stay at four stable positions without external force input. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a three-dimensional schematic diagram of a four-stable two-dimensional micro-motion platform of the present invention;

[0016] Figure 2 is a front view structural schematic diagram of a four-stable two-dimensional micro-motion platform of the present invention.

[0017] Reference numerals: 10 - base, 11 - hollow groove, 11a - bottom surface of the groove, 11b - side groove wall, 20 - moving platform, 30 - stacked piezoelectric actuator, 40 - three-section fully compliant bistable mechanism, 41 - shuttle, 421 - rigid beam, 422 - shuttle-end flexible beam, 423 - base-end flexible beam, 50 - transmission beam assembly, 51 - transmission beam, 52 - transmission beam, 60 - shallow-cut elliptical flexible hinge. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] See Figure 1 and Figure 2 A four-stable two-dimensional micro-motion platform of the present invention includes a base 10, a moving platform 20, a stacked piezoelectric actuator 30, and a three-section fully compliant bistable mechanism 40. At both ends in the X-axis direction and both ends in the Y-axis direction of the moving platform, a set of transmission beam assemblies 50 are respectively connected. Each set of transmission beam assemblies is respectively connected to the base 10 through a set of three-section fully compliant bistable mechanisms 40. The distances a from the two groups of three-section fully compliant bistable mechanisms 40 located on the same axis to the center point O of the moving platform 20 are the same and the two groups of three-section fully compliant bistable mechanisms are parallel to each other. That is, in the present embodiment Figure 2 the left and right two groups of three-section fully compliant bistable mechanisms located in the X-axis direction are parallel to each other, and the upper and lower two groups of three-section fully compliant bistable mechanisms located in the Y-axis direction are parallel to each other; each set of fully compliant bistable mechanisms 40 is respectively arranged opposite to a stacked piezoelectric actuator 50.

[0019] Each set of transmission beam assemblies 50 includes two parallel transmission beams 51, 52. Among them, the two sets of transmission beam assemblies 50 located at both ends in the X-axis direction of the moving platform 20 are all arranged parallel to the X-axis direction, and the two sets of transmission beam assemblies 50 located at both ends in the Y-axis direction of the moving platform 20 are all arranged parallel to the Y-axis direction.

[0020] Both ends of the transmission beams 51 and 52 are respectively connected to the moving platform 20 and the three - segment fully compliant bistable mechanism through a shallow - cut elliptical flexible hinge 60.

[0021] Each set of three - segment fully compliant bistable mechanisms 40 respectively includes a shuttle 41 and four sets of connecting beam assemblies. One side of the shuttle 41 facing the moving platform 20 is the moving - platform connection surface. The moving - platform connection surface is connected to the moving platform 20 through a set of transmission beam assemblies 50. Two opposite end faces of the shuttle 41 that face the base 10 and are adjacent to the moving - platform connection surface are respectively connected to the base 10 through two sets of connecting beam assemblies; each set of connecting beam assemblies respectively includes a rigid beam 421 and two flexible beams. The two flexible beams are respectively the shuttle - end flexible beam 422 and the base - end flexible beam 423. Axial ends of the rigid beam 421 are respectively connected to one end of the shuttle - end flexible beam 422 and one end of the base - end flexible beam 423. And the other end of the shuttle - end flexible beam 422 is connected to the shuttle 41, and the other end of the base - end flexible beam 423 is connected to the base 10; and the included angle formed by the shuttle - end flexible beam 422 and the shuttle 41 is non - right - angled.

[0022] The base 10 is a cuboid structure, and a pair of opposite faces of the base 10 are square faces. In this embodiment, the top surface and the bottom surface of the base 10 are square faces; on a pair of opposite square faces of the base 10, there are through - cut cross - shaped hollow grooves 11. The cross - shaped hollow groove 11 has four cross - connected rectangular through - grooves. Each rectangular through - groove respectively has a groove bottom surface 11a and side groove walls 11b on both sides of the groove bottom surface 11a; the moving platform 20 is located within the through - cut cross - shaped hollow groove 11, and stack piezoelectric actuators 30 are respectively fixedly installed at the central positions of the four groove bottom surfaces 11a of the cross - shaped hollow groove.

[0023] The moving platform 20 is a cuboid structure and a pair of opposite faces of it are square faces. In this embodiment, the top surface and the bottom surface of the moving platform 20 are square faces. A pair of square faces of the moving platform 20 are arranged parallel to a pair of square faces of the base. The base - end flexible beams 423 in the three - segment fully compliant bistable mechanisms respectively connected to the X - axis two ends and Y - axis two ends of the cuboid - structured moving platform 20 are fixedly connected to the side groove walls 11b of the cross - shaped hollow groove 11 of the base 10.

[0024] The base 10, the moving platform 20, the three - segment fully compliant bistable mechanism 40, the shallow - cut elliptical flexible hinge 60, and the transmission beam assemblies are an integral structure and can be integrally formed by methods such as wire - cutting, 3D printing, or casting.

[0025] In the present invention, the shallow-notch elliptical flexible hinge 60 is a common and well-known structural component in the technical field. For details, please refer to: (1) Smith S T, Badan I V G, Dale J S, et al. Elliptial flexure hingles [J]. Review of Scientific Instruments, 1997, 68(3): 1474-1483; (2) Chen Guimin, Liu Xiaoyuan, Jia Jianyuan. Flexibility calculation of elliptical flexible hinges [J]. Chinese Journal of Mechanical Engineering, 2006, 42: 111-115.

[0026] The steady-state position is the static equilibrium point. The three-stage fully compliant bistable mechanism 40 in the present invention has two steady-state positions. When an external force is applied to the shuttle 41 in this bistable mechanism, each flexible component will undergo bending deformation. That is, at this time, the shuttle-end flexible beam 422 and the base-end flexible beam 423 in the connecting beam assembly connected to the shuttle 41 will both undergo bending deformation, so that the shuttle 41 and each component in the connecting beam assembly connected to it are not in the same horizontal plane. As a result, a notch will appear between the shuttle 41 and the connecting beam assembly connected to it, and the shuttle 41 is located at the bottom of the notch. When the force reaches the critical jump force, the orientation of the notch will change, and at the same time, the mechanism will reach the second steady-state point. The moving platform 20 is provided with two groups of three-stage fully compliant bistable mechanisms 40 in the two axial directions of the X-axis and the Y-axis respectively. Therefore, there are two steady-state points corresponding to each axis. Combining the steady-state positions on the two axes, it can be obtained that the moving platform 20 of the present invention has four steady-state positions.

[0027] The above has described the specific implementation of the present invention in detail, but the content is only a preferred implementation of the present invention, and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A four-stable two-dimensional micro-motion platform, which comprises a base, a moving platform and a stacked piezoelectric actuator, and is characterized in that: It further includes a three - stage fully compliant bistable mechanism. At both ends of the moving platform in the X - axis direction and both ends in the Y - axis direction, a set of transmission beam assemblies are respectively connected. Each set of the transmission beam assemblies is respectively connected to the base through a set of the three - stage fully compliant bistable mechanisms. The distances from the two sets of the three - stage fully compliant bistable mechanisms located on the same axis to the center point of the moving platform are the same and the two sets of the three - stage fully compliant bistable mechanisms are parallel to each other. Each set of the fully compliant bistable mechanisms is respectively arranged opposite to a stack piezoelectric actuator, and the stack piezoelectric actuator is fixedly installed on the base; Each set of the three - stage fully compliant bistable mechanisms respectively includes a shuttle and four sets of connecting beam assemblies. The side surface of the shuttle facing the moving platform is the moving - platform connection surface. The moving - platform connection surface is connected to the moving platform through the set of transmission beam assemblies. The two opposite end faces of the shuttle, which are respectively facing the base and adjacent to the moving - platform connection surface, are respectively connected to the base through two sets of the connecting beam assemblies; Each set of the connecting beam assemblies respectively includes a rigid beam and two flexible beams. The two flexible beams are respectively a shuttle - end flexible beam and a base - end flexible beam. The two axial ends of the rigid beam are respectively connected to one ends of the shuttle - end flexible beam and the base - end flexible beam, and the other end of the shuttle - end flexible beam is connected to the shuttle, and the other end of the base - end flexible beam is connected to the base.

2. The four-stable two-dimensional micro-motion platform according to claim 1, characterized in that: Each set of the transmission beam assemblies includes two parallel - arranged transmission beams. Among them, the two sets of transmission beam assemblies located at both ends of the moving platform in the X - axis direction are all parallel - arranged along the X - axis direction, and the two sets of transmission beam assemblies located at both ends of the moving platform in the Y - axis direction are all parallel - arranged along the Y - axis direction.

3. The four-stable two-dimensional micro-motion platform according to claim 2, characterized in that: Both ends of each transmission beam are respectively connected to the moving platform and the three - stage fully compliant bistable mechanism through a shallow - cut elliptical flexible hinge.

4. A four-stable two-dimensional micro-motion platform according to claim 1, characterized in that: The connection angle formed by the shuttle - end flexible beam and the shuttle is not a right angle.

5. A four-stable two-dimensional micro-motion platform according to claim 4, characterized in that: The base is a cuboid structure, and a set of opposite faces of the base are square faces.

6. A four-stable two-dimensional micro-motion platform according to claim 5, characterized in that: On a pair of opposite square faces of the base, there are through - cut cross - shaped hollow grooves. The moving platform is located within the cross - shaped hollow grooves, and a stack piezoelectric actuator is fixedly installed at the central position of the four groove bottom surfaces of the cross - shaped hollow grooves respectively.

7. A four-stable two-dimensional micro-motion platform according to claim 5 or 6, characterized in that: The moving platform is a cuboid structure and a pair of opposite faces of it are square faces. The pair of square faces of the moving platform are parallel to the pair of square faces of the base. The base - end flexible beams in the three - stage fully compliant bistable mechanisms respectively connected to both ends of the moving platform in the X - axis direction and both ends in the Y - axis direction of the cuboid - structured moving platform are fixedly connected to the side groove walls of the cross - shaped hollow grooves of the base.

8. A four-stable two-dimensional micro-motion platform according to claim 3, characterized in that: The base, the moving platform, the three - stage fully compliant bistable mechanism, the shallow - cut elliptical flexible hinge, and the transmission beam are of an integral structure.

Images