A helically coupled driven clamping twisting synchronous piezoelectric micromanipulator

Abstract

This invention proposes a helically coupled piezoelectric micromanipulator for synchronous clamping and twisting, belonging to the field of piezoelectric precision micro-nano manipulation technology. It includes a multi-finger clamping and twisting flexible mechanism, a threaded drive shaft, a threaded preload mechanism, a piezoelectric drive assembly, and a fixed base. The piezoelectric drive assembly drives the threaded drive shaft to generate helical coupling motion, which in turn drives the multi-finger clamping and twisting flexible mechanism to synchronously generate clamping and twisting motions. In inertial drive mode, the object is clamped and twisted during the adhesive motion phase, and the fingers are opened during the sliding motion phase to increase the output force and reduce the return displacement, achieving large-stroke twisting. This invention utilizes a single piezoelectric unit and helical coupling transmission to achieve synchronous clamping and twisting, solving the problems of complex overall structure and large size caused by the need for multiple sets of piezoelectric units in transmission-based piezoelectric micromanipulators for clamping and twisting. It is suitable for the twisting and assembly of micro-shaft parts.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric precision micro-nano manipulation technology, specifically, it relates to a helically coupled driven clamping and twisting synchronous piezoelectric micromanipulator. Background Technology

[0002] As the manipulated objects in fields such as precision manufacturing, biomedicine, and aerospace continue to extend to the micro- and nano-scale, the demand for precise and flexible manipulation of these objects is becoming increasingly urgent. As the end-effectors of micro- and nano-manipulation systems, the output performance and structural integration of micromanipulators directly determine the efficiency and quality of micromanipulation. Benefiting from the advantages of piezoelectric actuation—high precision, rapid response, and absence of electromagnetic interference—various piezoelectric micromanipulators are widely researched and applied.

[0003] Current mainstream piezoelectric micromanipulators mostly utilize the telescopic motion of piezoelectric stacks, amplifying the end-effector displacement and changing the direction of motion through flexible hinge amplification mechanisms. A single piezoelectric element can only achieve clamping and opening / closing functions. However, in practical micromanipulation scenarios, such as the screwing and assembly of micro-shaft parts and the orientation adjustment of single cells, not only is stable clamping of the manipulated object required, but also synchronous or independent twisting motion. To achieve multi-dimensional micromanipulation, existing technologies mostly adopt a scheme of multiple sets of piezoelectric units working together. However, the discrete layout of multiple sets of piezoelectric units leads to a complex overall structure, large size, and low integration, making it difficult to adapt to the needs of use in confined operating spaces. The motion output form of threaded transmission is linear-rotational coupling. This invention utilizes a linear and rotational coupled helical drive, through a multi-finger flexible mechanism, to achieve synchronous clamping and twisting motion of the piezoelectric micromanipulator, thereby improving the efficiency of micro-nano screwing and assembly. Summary of the Invention

[0004] In order to solve the problem that existing piezoelectric micromanipulators require multiple piezoelectric units to achieve clamping and twisting, resulting in a complex structure, this invention proposes a synchronous piezoelectric micromanipulator for clamping and twisting driven by helical coupling.

[0005] This invention is achieved through the following technical solution: A helically coupled, driven, clamping, twisting, synchronous piezoelectric micromanipulator: The piezoelectric micromanipulator includes: a multi-finger gripping and twisting flexible mechanism, a threaded drive shaft, a threaded preload mechanism, a piezoelectric drive assembly, and a fixed base; The multi-finger gripping and twisting flexible mechanism consists of gripping fingers, an angle adjustment unit, a flexible hinge, a spiral connector, and a precision threaded sleeve. The spiral connector of the multi-finger gripping and twisting flexible mechanism is fixedly connected to the upper end of the threaded drive shaft. The threaded drive shaft is threadedly engaged with the precision threaded sleeve. The precision threaded sleeve is fixedly installed on the upper end of the piezoelectric drive assembly, and the piezoelectric drive assembly is fixedly installed on the upper end of the fixed base; The piezoelectric drive assembly is driven to the threaded drive shaft and is used to drive the threaded drive shaft to rotate around its own axis. The thread preload mechanism is sleeved on the outside of the threaded drive shaft, with its lower end abutting against the fixed base and its upper end abutting against the shoulder end face of the threaded drive shaft, and is used to eliminate the meshing gap between the threaded drive shaft and the precision threaded sleeve.

[0006] Furthermore, the number of clamping fingers is greater than or equal to 2, and they are evenly distributed in a circumferential direction; The flexible hinge is a multi-axis rotary pair flexible hinge; The spiral connector is connected in parallel with each clamping finger via a flexible hinge, so as to simultaneously realize the opening and closing clamping action of the clamping finger and the circumferential posture adjustment of the clamped object. The ratio between the opening and closing stroke of the gripping finger and the twisting angle is adjusted by the displacement of the flexible hinge arrangement.

[0007] Furthermore, the angle adjustment unit has an angle attitude locking function, which enables stepless angle adjustment; The initial opening angle of the gripping finger is adjusted by the angle adjustment unit.

[0008] Furthermore, the piezoelectric drive assembly achieves rotational drive of the threaded drive shaft through the shearing mode, longitudinal-torsional motion conversion mode, and tangential linear drive mode of the piezoelectric unit.

[0009] Furthermore, the threaded drive shaft is used to achieve precise linear and rotary coupling of helical transmission within the forward and reverse strokes; The threaded drive shaft adopts a self-locking thread profile design, and the equivalent friction angle of the self-locking thread profile is greater than the thread helix angle, realizing a mechanical self-locking structure when power is off.

[0010] A control method for a helically coupled driven synchronous piezoelectric micromanipulator for clamping and twisting; The method includes the following steps: S1. The piezoelectric drive assembly applies a drive signal to drive the threaded drive shaft to rotate around its own axis. S2. The threaded drive shaft converts rotational motion into helical motion coupled with linear rotation through threaded engagement with a precision threaded sleeve. S3. The spiral connector moves synchronously with the threaded drive shaft, and drives all the gripping fingers to move synchronously through the flexible hinge, so as to realize the gripping or twisting operation of the manipulated object.

[0011] Furthermore, the upward linear motion of the threaded drive shaft will drive the gripping fingers to perform a synchronous opening motion through the helical connector; The downward linear motion of the threaded drive shaft will drive the gripping fingers to perform a synchronous closing motion through the helical connector. The helical motion of the threaded drive shaft will drive the gripping fingers to rotate synchronously and in the same direction through the helical connector. Furthermore, the piezoelectric drive assembly applies a sawtooth wave drive signal; During the adhesive motion phase, the threaded drive shaft drives the gripping fingers to perform a synchronous closing motion, increasing the gripping force between the gripping fingers and the manipulated object, and increasing the output force of the inertial motion during the adhesive motion phase. During the sliding motion phase, the threaded drive shaft drives the gripping fingers to perform a synchronous opening motion, reducing the gripping force between the gripping fingers and the manipulated object, and reducing the backward displacement of inertial motion during the sliding motion phase.

[0012] Furthermore, by adjusting the direction of the threaded engagement between the precision threaded sleeve and the threaded drive shaft, the coupling form between the clockwise and counterclockwise rotational motion direction and the up-down linear motion direction of the threaded drive shaft can be controlled. The clockwise and counterclockwise rotation angles and vertical linear motion stroke of the threaded drive shaft are adjusted by the thread pitch of the precision threaded sleeve and the threaded drive shaft.

[0013] Furthermore, the piezoelectric drive component applies a periodic sawtooth wave signal to drive the multi-finger gripping and twisting flexible mechanism to achieve continuous large-stroke twisting motion on the manipulated object; The piezoelectric drive component applies a tiny DC signal, which drives the multi-finger gripping and twisting flexible mechanism to achieve precise twisting and adjustment of the manipulated object.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention provides a helical coupling driven synchronous piezoelectric micromanipulator for clamping and twisting, which realizes the synchronization of clamping opening and closing and circumferential twisting motion through helical coupling drive, and solves the complex structure of traditional micromanipulators that require multiple sets of drive units for separate drive and control for clamping and twisting compound operation. 2. The helical coupling driven clamping and twisting synchronous piezoelectric micromanipulator of the present invention increases the clamping force in the inertial drive viscous motion stage and decreases the clamping force in the sliding motion stage, thereby increasing the output force of the inertial viscous-sliding drive and reducing the back displacement. 3. The helical coupling driven synchronous piezoelectric micromanipulator described in this invention can be adapted to objects with different outer diameters and different specifications through the angle adjustment unit, so as to realize the clamping and twisting operation of the objects to be manipulated; 4. The helical coupling driven synchronous piezoelectric micromanipulator for clamping and twisting, as described in this invention, can flexibly match the clamping stroke, clamping force threshold, and twisting rotation angle range under different application scenarios through the parameterized adjustable design of threaded transmission and flexible hinge. Attached Figure Description

[0015] Figure 1 A three-dimensional structural schematic diagram of a helically coupled, driven, clamping, twisting, synchronous piezoelectric micromanipulator; Figure 2 A three-dimensional structural diagram of a multi-finger gripping and twisting flexible mechanism; Figure 3 This is a schematic diagram showing the angle adjustment of a multi-finger gripping and twisting flexible mechanism; Figure 4 This is a schematic diagram of a rotation actuation scheme for a piezoelectric drive component, where (a) is a schematic diagram of the deformation of the piezoelectric unit in shear mode, and (b) is a schematic diagram of the deformation of the longitudinal-torsional motion conversion mode. Figure 5 A schematic diagram showing the inertial stick-slip actuation excitation signal and rotation angle; Figure 6 The action sequence of the inertial stick-slip actuated multi-finger gripping and twisting flexible mechanism; 1-Multi-finger gripping and twisting flexible mechanism; 1-1-Gripping finger; 1-2-Angle adjustment unit; 1-3-Flexible hinge; 1-4-Spiral connector; 1-5-Precision threaded sleeve; 2-Threaded drive shaft; 3-Threaded preload mechanism; 4-Piezoelectric drive assembly; 5-Fixed base. Detailed Implementation

[0016] The following will refer to the appendices in the embodiments of the present invention. Figures 1 to 6 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0018] Example 1: A helically coupled driven clamping and twisting synchronous piezoelectric micromanipulator: The piezoelectric micromanipulator includes: a multi-finger gripping and twisting flexible mechanism 1, a threaded drive shaft 2, a threaded preload mechanism 3, a piezoelectric drive assembly 4, and a fixed base 5; The multi-finger gripping and twisting flexible mechanism 1 consists of a gripping finger 1-1, an angle adjustment unit 1-2, a flexible hinge 1-3, a spiral connector 1-4, and a precision threaded sleeve 1-5. The spiral connector 1-4 of the multi-finger gripping and twisting flexible mechanism is fixedly connected to the threaded drive shaft 2. The precision threaded sleeves 1-5, the piezoelectric drive assembly 4, and the fixed base 5 are fixedly connected.

[0019] The number of the clamping fingers 1-1 is greater than or equal to 2, and they are evenly distributed around the circumference. Preferably, there are 3 clamping fingers 1-1 to achieve three-point positioning clamping. The flexible hinges 1-3 of the multi-finger gripping and twisting flexible mechanism 1 are multi-axis rotating pair flexible hinges, which can be circular, elliptical, leaf-shaped, etc.

[0020] The spiral connector 1-4 is connected in parallel with each clamping finger 1-1 via a flexible hinge 1-3, so as to simultaneously realize the opening and closing clamping action of the clamping finger 1-1 and the circumferential posture adjustment of the clamped object. The ratio between the opening and closing stroke of the clamping finger 1-1 and the twisting angle is adjusted by the arrangement and displacement of the flexible hinge 1-3. The two ends of the thread preload mechanism 3 abut against the shoulder end face of the fixed base 5 and the thread drive shaft 2 respectively, in order to eliminate the meshing gap between the thread drive shaft 2 and the precision thread sleeve 1-5, and ensure the accuracy of the screw drive and the accuracy of the return repeatability positioning.

[0021] The initial opening angle of the gripping fingers 1-1 of the multi-finger gripping and twisting flexible mechanism can be precisely adjusted by the angle adjustment unit 1-2 to adapt to objects with different outer diameters and different sizes, so as to realize the gripping and twisting operation of the objects to be manipulated. The angle adjustment unit 1-2 can achieve stepless angle adjustment and has an angle attitude locking function; The piezoelectric drive assembly 4 can achieve rotational drive of the threaded drive shaft 2 through the shearing mode, longitudinal-torsional motion conversion mode, and tangential linear drive mode of the piezoelectric unit; The threaded drive shaft 2 is used to realize a helical drive with precise linear and rotary coupling within the forward and reverse strokes; The threaded drive shaft 2 adopts a self-locking thread profile design. The equivalent friction angle of the self-locking thread profile is greater than the thread helix angle, realizing a mechanical self-locking structure when power is off. Example 2: A control method for a helically coupled driven clamping and twisting synchronous piezoelectric micromanipulator; The piezoelectric drive assembly 4 drives the threaded drive shaft 2 to perform a linear and rotationally coupled helical motion by applying a sawtooth wave drive signal. The upward linear motion of the threaded drive shaft 2 will drive the gripping fingers 1-1 to open synchronously through the helical connector 1-4; The downward linear motion of the threaded drive shaft 2 will drive the clamping fingers 1-1 to perform a synchronous closing motion through the helical connector 1-4; The rotational motion of the threaded drive shaft 2 will drive the gripping fingers 1-1 to rotate synchronously and in the same direction through the helical connector 1-4; The coupling between the clockwise and counterclockwise rotational motion direction and the up-down linear motion direction of the threaded drive shaft 2 is controlled by the threaded engagement between the precision threaded sleeve 1-5 and the threaded drive shaft 2. The clockwise and counterclockwise rotation angles and the vertical linear motion strokes of the threaded drive shaft 2 are adjusted by the thread pitch of the threaded fit between the precision threaded sleeve 1-5 and the threaded drive shaft 2. The piezoelectric drive assembly 4 applies a sawtooth wave drive signal. During the adhesive motion phase, the threaded drive shaft 2 drives the gripping fingers 1-1 to perform a synchronous closing motion, increasing the gripping force between the gripping fingers 1-1 and the manipulated object, thereby increasing the output force of the inertial motion during the adhesive motion phase. The piezoelectric drive assembly 4 applies a sawtooth wave drive signal. During the sliding motion phase, the threaded drive shaft 2 drives the clamping fingers 1-1 to perform synchronous opening motion, reducing the clamping force between the clamping fingers 1-1 and the manipulated object, thereby reducing the backward displacement of the inertial motion during the sliding motion phase. The piezoelectric drive component 4 applies a periodic sawtooth wave signal, which drives the multi-finger gripping and twisting flexible mechanism 1 to achieve continuous large-stroke twisting motion on the manipulated object. The piezoelectric drive component 4 applies a tiny DC signal to drive the multi-finger gripping and twisting flexible mechanism 1 to achieve precise twisting and adjustment of the manipulated object. like Figure 6 The action sequence of the inertial stick-slip actuated multi-finger gripping and twisting flexible mechanism; Initial stage: The initial opening angle of the gripping fingers of the multi-finger gripping and twisting flexible mechanism is precisely adjusted by the angle adjustment unit to adapt to objects with different outer diameters and different sizes. Adhesive motion stage: The gripping fingers perform synchronous closing movements, increasing the gripping force between the gripping fingers and the manipulated object, and the friction drives the manipulated object to generate rotational motion; During the sliding motion phase: the gripping fingers perform a synchronized opening and closing motion, reducing the gripping force between the gripping fingers and the manipulated object, and the friction drives the manipulated object to produce a retracting rotational motion.

[0022] The foregoing has provided a detailed description of the helical coupling driven clamping and twisting synchronous piezoelectric micromanipulator proposed in this invention, and has elucidated the principle and implementation of this invention. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this invention; at the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A helically coupled driven clamping and twisting synchronous piezoelectric micromanipulator, characterized in that: The piezoelectric micromanipulator includes: a multi-finger gripping and twisting flexible mechanism (1), a threaded drive shaft (2), a threaded preload mechanism (3), a piezoelectric drive assembly (4), and a fixed base (5). The multi-finger gripping and twisting flexible mechanism (1) consists of gripping fingers (1-1), an angle adjustment unit (1-2), a flexible hinge (1-3), a spiral connector (1-4), and a precision threaded sleeve (1-5); The spiral connector (1-4) of the multi-finger gripping and twisting flexible mechanism is fixedly connected to the upper end of the threaded drive shaft (2); The threaded drive shaft (2) is threadedly engaged with the precision threaded sleeve (1-5); The precision threaded sleeve (1-5) is fixedly installed on the upper end of the piezoelectric drive assembly (4), and the piezoelectric drive assembly (4) is fixedly installed on the upper end of the fixed base (5); The piezoelectric drive assembly (4) is driven to connect with the threaded drive shaft (2) and is used to drive the threaded drive shaft (2) to rotate around its own axis; The thread preload mechanism (3) is sleeved on the outside of the thread drive shaft (2), with its lower end abutting against the fixed base (5) and its upper end abutting against the shoulder end face of the thread drive shaft (2), and is used to eliminate the meshing gap between the thread drive shaft (2) and the precision threaded sleeve (1-5).

2. The piezoelectric micromanipulator according to claim 1, characterized in that: The number of the clamping fingers (1-1) is greater than or equal to 2, and they are evenly distributed in the circumferential direction; The flexible hinge (1-3) is a multi-axis rotary pair flexible hinge; The spiral connector (1-4) is connected in parallel with each clamping finger (1-1) via a flexible hinge (1-3), so as to simultaneously realize the opening and closing clamping action of the clamping finger (1-1) and the circumferential posture adjustment of the clamped object; The ratio between the opening and closing stroke of the gripping finger (1-1) and the twisting angle is adjusted by the arrangement and displacement of the flexible hinge (1-3).

3. The piezoelectric micromanipulator according to claim 2, characterized in that: The angle adjustment unit (1-2) has an angle attitude locking function, which enables stepless angle adjustment; The initial opening angle of the gripping finger (1-1) is adjusted by the angle adjustment unit (1-2).

4. The piezoelectric micromanipulator according to claim 3, characterized in that: The piezoelectric drive assembly (4) achieves rotational drive of the threaded drive shaft (2) through the shearing mode, longitudinal-torsional motion conversion mode, and tangential linear drive mode of the piezoelectric unit.

5. The piezoelectric micromanipulator according to claim 4, characterized in that: The threaded drive shaft (2) is used to realize a helical drive with precise linear and rotary coupling in both forward and reverse strokes; The threaded drive shaft (2) adopts a self-locking thread profile design. The equivalent friction angle of the self-locking thread profile is greater than the thread helix angle, thus realizing a mechanical self-locking structure when the power is off.

6. A control method of a clamping-twist-synchronous piezoelectric micro-manipulator driven by a screw coupling, characterized in that: The method is based on the helical coupling driven clamping twisting synchronous piezoelectric micromanipulator as described in any one of claims 1 to 5; The method includes the following steps: S1. The piezoelectric drive assembly (4) applies a drive signal to drive the threaded drive shaft (2) to rotate around its own axis. S2, the threaded drive shaft (2) converts the rotational motion into a linear-rotational coupled helical motion by engaging with the threaded sleeve (1-5); S3, the spiral connector (1-4) moves synchronously with the threaded drive shaft (2), and drives all the gripping fingers (1-1) to move synchronously through the flexible hinge (1-3) to realize the gripping or twisting operation of the manipulated object.

7. The control method according to claim 6, characterized in that: When the threaded drive shaft (2) moves upward in a straight line, it drives the gripping fingers (1-1) to open synchronously through the helical connector (1-4); When the threaded drive shaft (2) moves downward in a straight line, it drives the gripping fingers (1-1) to perform a synchronous closing motion through the helical connector (1-4); When the threaded drive shaft (2) moves in a spiral motion, it drives the gripping fingers (1-1) to rotate synchronously and in the same direction through the spiral connector (1-4).

8. The control method according to claim 7, characterized in that: The piezoelectric drive component (4) applies a sawtooth wave drive signal, and the drive process is divided into two stages; During the adhesive motion phase, the threaded drive shaft (2) drives the clamping fingers (1-1) to perform synchronous closing motion, increasing the clamping force between the clamping fingers (1-1) and the manipulated object, and increasing the output force of the inertial motion during the adhesive motion phase. During the sliding motion phase, the threaded drive shaft (2) drives the clamping fingers (1-1) to perform synchronous opening motion, reducing the clamping force between the clamping fingers (1-1) and the manipulated object, and reducing the backward displacement of inertial motion during the sliding motion phase.

9. The control method according to claim 8, characterized in that: By adjusting the direction of the threaded engagement between the precision threaded sleeve (1-5) and the threaded drive shaft (2), the clockwise and counterclockwise rotational motion and the up-down linear motion of the threaded drive shaft (2) can be controlled. The clockwise and counterclockwise rotation angles and vertical linear motion strokes of the threaded drive shaft (2) are adjusted by the thread pitch of the precision threaded sleeve (1-5) and the threaded drive shaft (2).

10. The control method according to claim 1, characterized in that: The piezoelectric drive component (4) applies a periodic sawtooth wave signal to drive the multi-finger gripping and twisting flexible mechanism (1) to achieve continuous large-stroke twisting motion on the manipulated object; The piezoelectric drive component (4) applies a tiny DC signal to drive the multi-finger gripping and twisting flexible mechanism (1) to achieve precise twisting and adjustment of the manipulated object.

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