Opening and closing type single-drive piezoelectric micro clamp and using method thereof

Abstract

The invention discloses an open-close type single-drive piezoelectric micro-clamp and a using method thereof, and belongs to the technical field of micro-operation. The left side and the right side of the composite rhombus amplifying mechanism are sequentially and symmetrically arranged from inside to outside and connected with the lever amplifying mechanisms and the parallelogram mechanisms, and the output ends of the two parallelogram mechanisms are symmetrically connected with the two clamping parts of the jaw respectively. The composite rhombus amplification mechanism, the lever amplification mechanisms and the parallelogram mechanism are all installed on the base through fixing bolts, the fulcrum positions of the two lever amplification mechanisms are each externally connected with a mode conversion block capable of being detachably connected with the base, and the mode conversion blocks can be detachably connected with the base by changing the connecting state of the mode conversion blocks and the base. And the micro clamp is a two-stage amplification mechanism or a three-stage amplification mechanism, so that the jaw completes the clamping or opening action. According to the invention, by mounting and dismounting the specified fixing bolt, the magnification stage number of the micro-clamp and the change of the movement direction of the jaw can be realized, and the problem that the jaw of the micro-clamp cannot be opened and closed at the initial position under the driving of a single piezoelectric actuator is solved.

Description

Technical Field

[0001] This invention belongs to the field of micromanipulation technology, specifically relating to an openable single-drive piezoelectric microgripper and its usage method. Background Technology

[0002] With the rapid development of high-tech such as micro- and nanotechnology, new challenges have been posed to the motion, positioning, and control of micrometer-level precision. Traditional precision rigid transmission mechanisms can no longer meet practical work requirements, while compliant mechanisms, with their advantages of high motion accuracy, light weight, frictionless operation, lubrication-free operation, and compact structure, have become an important form of realization for micro-operating systems. Microgrippers, as the end effector of micro-operating systems, play a decisive role in the success of micro-manipulation tasks. Microgrippers are widely used in cutting-edge scientific and technological fields such as special machining, grating splicing, biological and genetic engineering, materials science, minimally invasive surgery, and aerospace.

[0003] Piezoelectric actuators are widely used in micro clamps due to their fast response and high sensitivity. However, on the one hand, piezoelectric actuators have relatively small deformation, so micro clamps require displacement amplification mechanisms to achieve a larger operating range; on the other hand, when a piezoelectric actuator is energized, it can only apply thrust to the connected mechanism. Therefore, traditional mechanisms have limitations in jaw movement, initially only able to open or close, making it difficult to simultaneously achieve both jaw opening and closing.

[0004] For example, the following five patents: 1. Invention patent with patent number 202211652822.9 discloses a micro-gripper for micromanipulation and its adjustment method. The invention patent provides a two-stage amplified single-drive piezoelectric micro gripper that can only achieve the closing action of the jaws.

[0005] 2. Invention patent with patent number 202510447240.4 discloses a micro gripper based on a flexible crank-slider mechanism. This invention patent is based on a single-drive piezoelectric micro gripper designed with a flexible crank-slider mechanism. It has a single amplification stage and can only realize the opening action of the jaws.

[0006] 3. Invention patent with patent number 202210664527.9 discloses a piezoelectrically driven three-jaw micro gripper. The invention patent reports a single-drive piezoelectric micro gripper with a two-stage amplification and a three-jaw gripping mechanism, but it can only achieve the closing action of the jaws.

[0007] 4. Invention patent with patent number 202210713379.5 discloses a parallel output piezoelectric driven micro gripper. The invention patent reports a single-drive piezoelectric micro gripper with a single amplification stage. The final amplification mechanism adopts a parallelogram mechanism, which can only realize the closing action of the jaws.

[0008] 5. Invention patent with patent number 202410291633.6 discloses a constant force flexible micro-clamp. The invention patent reports a single-drive piezoelectric micro gripper with a two-stage amplification level, capable of constant force output within a specific range, and only able to achieve the closing action of the jaws. Summary of the Invention

[0009] In order to solve the problems of the current single-drive piezoelectric micro clamps, which have a single direction of motion and a limited range of motion, this invention provides an opening and closing single-drive piezoelectric micro clamp and its usage method.

[0010] The technical solution adopted in this invention is: A single-drive piezoelectric microgripper with opening and closing mechanism includes a composite rhomboid amplification mechanism, a lever amplification mechanism, a parallelogram mechanism, and a mode conversion block. The composite rhomboid amplification mechanism is symmetrically arranged and connected to the lever amplification mechanism and the parallelogram mechanism from the inside to the outside on both sides. The output ends of the two parallelogram mechanisms are symmetrically connected to the two clamping parts of the jaws. The composite rhomboid amplification mechanism, the lever amplification mechanism, and the parallelogram mechanism are all mounted on a base by fixing bolts. A mode conversion block that can be detachably connected to the base is externally connected to the fulcrum position of each of the two lever amplification mechanisms. By changing the connection state between the mode conversion block and the base, the microgripper can be a two-stage amplification mechanism or a three-stage amplification mechanism, thereby enabling the jaws to perform clamping or opening actions.

[0011] Furthermore, the composite rhomboid amplification mechanism includes a movable end, a fixed end, and two amplification units; the two amplification units are symmetrically connected between the movable end and the fixed end, and the fixed end is mounted on the base by fixing bolts.

[0012] Furthermore, each of the amplification units includes an output rod and four amplification rods; the four amplification rods are divided into two groups, with the output rod located in the middle of the two groups of amplification rods, one end of each amplification rod being connected to the output rod, and the other end of each amplification rod being connected to the corresponding moving end or fixed end.

[0013] Furthermore, a piezoelectric actuator is placed between the two amplification units of the composite rhombic amplification mechanism. The piezoelectric actuator is fixed to the fixed end of the composite rhombic amplification mechanism by a pre-tightening bolt, and the output end of the piezoelectric actuator is connected to the moving end of the composite rhombic amplification mechanism.

[0014] Furthermore, the main body of the lever amplification mechanism adopts a rod-shaped structure, the input end of the lever amplification mechanism is flexibly connected to the middle of the amplification unit of the composite rhombic amplification mechanism, the output end of the lever amplification mechanism is flexibly connected to the parallelogram mechanism, and the fulcrum position of the lever amplification mechanism is flexibly connected to the mode conversion block.

[0015] Furthermore, the mode conversion block has threaded holes and is detachably connected to the base by fixing bolts.

[0016] Furthermore, the two clamping parts of the jaws are symmetrically arranged on the left and right, and the two clamping parts are flexibly connected to the output end of the corresponding parallelogram mechanism.

[0017] A method for using an openable single-drive piezoelectric micro clamp includes the following steps: a pre-tightening bolt fixes the piezoelectric actuator inside the composite rhomboid amplification mechanism, a fixing bolt fixes the piezoelectric micro clamp on the base, and the piezoelectric actuator generates a vertical thrust after being energized. When the mode conversion block is not installed with the fixing bolt, the micro clamp is a two-stage amplification mechanism. The compound rhomboid amplification mechanism directly drives the parallelogram mechanism to move, thereby completing the clamping action of the jaws. When the mode conversion block is installed with the fixing bolts, the micro clamp is a three-stage amplification mechanism. The compound rhomboid amplification mechanism drives the lever amplification mechanism to move, and the lever amplification mechanism drives the parallelogram mechanism to move, thereby completing the opening action of the jaws.

[0018] Compared with the prior art, the present invention has the following advantages: This invention enables the microgripper to change its magnification level and jaw movement direction by installing and removing specified fixing bolts, thus solving the problem that microgrippers cannot open and close their jaws at the initial position when driven by a single piezoelectric actuator. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall installation of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention; Figure 3 This is a schematic diagram of the composite rhomboid amplification mechanism of the present invention; Figure 4 This is a schematic diagram of the lever amplification mechanism of the present invention; Figure 5 This is a schematic diagram of the parallelogram mechanism structure of the present invention; Figure 6 This is a force analysis diagram of the clamping state of the present invention; Figure 7 This is a force analysis diagram of the open state of this invention; Figure 8This is the finite element analysis model of the amplification performance under the second amplification stage of this invention; Figure 9 This is the finite element analysis model of the amplification performance under three amplification stages of this invention; The components are: 1. Base; 2. Preload bolt; 3. Piezoelectric actuator; 4. Composite rhomboid amplification mechanism; 401. Moving end; 402. Amplification unit; 4021. Output rod; 4022. Amplification rod; 403. Fixed end; 5. Lever amplification mechanism; 6. Parallelogram mechanism; 7. Fixing bolt; 8. Mode conversion block; 9. Jaw. Detailed Implementation

[0020] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0021] When the piezoelectric actuator is powered on, it extends longitudinally. When the power is turned off, it returns to its initial state. The micro clamp can open and close during operation, but in the initial state, it can only perform a single action, opening or closing.

[0022] For a microgripper to open and close in its initial state, the piezoelectric actuator must generate both pushing and pulling forces. However, when the microgripper is energized, the piezoelectric actuator can only produce longitudinal pushing force. Specifically, assuming the initial jaw position is 100μm, with a traditional microgripper, energizing the piezoelectric actuator causes the jaw spacing to change from 100μm to 0μm, and then return to 100μm after de-energizing (it can be said that opening and closing actions are achieved, but compared to the initial position, only closing, or clamping, action is performed). With a traditional microgripper that opens, energizing causes the jaw spacing to change from 100μm to 200μm, and de-energizing causes it to return to 100μm; compared to the initial position, only opening action is performed. In this invention, the micro clamp can open and close its jaws in the initial state, regardless of whether the bolt is installed or not, breaking the limitation of traditional micro clamps where the jaws can only perform a single action in the initial state.

[0023] like Figure 1 , Figure 2As shown, this invention provides an openable single-drive piezoelectric microgripper, comprising a composite rhomboid amplification mechanism 4, a lever amplification mechanism 5, a parallelogram mechanism 6, and a mode conversion block 8. The composite rhomboid amplification mechanism 4 is symmetrically arranged and connected to the lever amplification mechanism 5 and the parallelogram mechanism 6 from the inside to the outside on both sides. The output ends of the two parallelogram mechanisms 6 are symmetrically connected to the two clamping parts of the jaws 9. The composite rhomboid amplification mechanism 4, the lever amplification mechanism 5, and the parallelogram mechanism 6 are all mounted on the base 1 by fixing bolts 7. A mode conversion block 8 that can be detachably connected to the base 1 is externally connected to the fulcrum position of each of the two lever amplification mechanisms 5. By changing the connection state between the mode conversion block 8 and the base 1, the microgripper can be a two-stage amplification mechanism or a three-stage amplification mechanism, thereby enabling the jaws 9 to perform clamping or opening actions.

[0024] like Figure 3 As shown, the composite rhomboid amplification mechanism 4 includes a movable end 401, a fixed end 403, and two amplification units 402; the two amplification units 402 are symmetrically connected between the movable end 401 and the fixed end 403, and the fixed end 403 is mounted on the base 1 by fixing bolts 7.

[0025] like Figure 3 As shown, each amplification unit 402 includes an output rod 4021 and four amplification rods 4022; the four amplification rods 4022 are divided into two groups, the output rod 4021 is disposed in the middle of the two groups of amplification rods 4022, one end of each amplification rod 4022 is connected to the output rod 4021, and the other end of each amplification rod 4022 is connected to the corresponding moving end 401 or fixed end 403 respectively.

[0026] like Figure 3 As shown, a piezoelectric actuator 3 is placed between the two amplification units 402 of the composite rhombic amplification mechanism 4. The piezoelectric actuator 3 is fixed to the fixed end 403 of the composite rhombic amplification mechanism 4 by a pre-tightening bolt 2, and the output end of the piezoelectric actuator 3 is connected to the moving end 401 of the composite rhombic amplification mechanism 4.

[0027] like Figure 5 As shown, the main body of the lever amplification mechanism 5 adopts a rod-shaped structure. The input end of the lever amplification mechanism 5 is flexibly connected to the middle of the amplification unit 402 of the composite rhomboid amplification mechanism 4. The output end of the lever amplification mechanism 5 is flexibly connected to the parallelogram mechanism 6. The fulcrum position of the lever amplification mechanism 5 is flexibly connected to the mode conversion block 8.

[0028] like Figure 4 As shown, the mode conversion block 8 has a threaded hole and is detachably connected to the base 1 by a fixing bolt 7.

[0029] like Figure 1 , Figure 2 , Figure 5 As shown, the two clamping parts of the jaw 9 are symmetrically arranged on the left and right, and the two clamping parts are flexibly connected to the output end of the corresponding parallelogram mechanism 6.

[0030] The present invention provides a method for using an openable single-drive piezoelectric micro clamp, comprising the following steps: a pre-tightening bolt 2 fixes a piezoelectric actuator 3 inside a composite rhomboid amplification mechanism 4, a fixing bolt 7 fixes the piezoelectric micro clamp on a base 1, and the piezoelectric actuator 3 generates a vertical thrust after being energized. When the mode conversion block 8 is not installed with the fixing bolt 7, the micro clamp is a two-stage amplification mechanism. The lever amplification mechanism 5 only plays the role of force transmission. The compound rhomboid amplification mechanism 4 directly drives the parallelogram mechanism 6 to move, thereby completing the clamping action of the jaw 9. When the mode conversion block 8 is installed with the fixing bolt 7, the micro clamp is a three-stage amplification mechanism. The compound rhomboid amplification mechanism 4 drives the lever amplification mechanism 5 to move, and the lever amplification mechanism 5 drives the parallelogram mechanism 6 to move, thereby completing the opening action of the jaws 9.

[0031] Fix the microgripper to the base 1 and tighten all the bolts. At this time, it is a three-stage amplification mechanism. After the piezoelectric actuator 3 is energized, the microgripper jaws 9 close from the initial position. Loosen the fixing bolts 7 at the fulcrum position of the lever amplification mechanism 5. At this time, it is a two-stage amplification mechanism. After the piezoelectric actuator 3 is energized, the microgripper jaws 9 open from the initial position.

[0032] The opening and closing piezoelectric micro clamp of the present invention can operate micro parts with dimensions larger than or smaller than the jaw spacing 9, increasing the operating range and applicability of the micro clamp.

[0033] The initial gap distance of jaws 9 is typically the size of the micro clamp's closed operation. When the micro-part size is smaller than the gap distance of jaws 9, tightening all bolts will allow the micro clamp jaws 9 to hold the micro-part. When the micro-part size is larger than the gap distance of jaws 9, the bolts at the fulcrum of the lever amplification mechanism 5 can be loosened to allow the micro clamp to open its jaws 9. Afterward, the voltage can be reduced to complete the clamping action.

[0034] Figure 6 and Figure 7 The diagram shows the force analysis of the micro clamp in two different configurations. Figure 6 Without fixing bolt 7 installed at the fulcrum of the lever amplification mechanism 5, the piezoelectric actuator 3 applies a horizontal upward force, and the left output end of the compound rhomboid amplification mechanism 4 generates a rightward force. At this time, both the input and output ends of the lever amplification mechanism 5 generate a rightward force, which in turn drives the parallelogram mechanism 6 to generate a horizontal rightward force (the parallelogram mechanism has parallel clamping characteristics), and the jaws 9 complete the clamping action.

[0035] Figure 7A fixing bolt 7 is installed at the fulcrum of the lever amplification mechanism 5. The piezoelectric actuator 3 applies a horizontal upward force, and the output end of the compound rhomboid amplification mechanism 4 generates a rightward force. At this time, the input end of the lever amplification mechanism 5 generates a rightward force, and the output end generates a leftward force, which in turn drives the parallelogram mechanism 6 to generate a horizontal leftward force (the parallelogram mechanism has parallel clamping characteristics), and the jaws 9 complete the opening action.

[0036] This invention mentions finite element analysis models of the amplification performance of microclamps under two amplification levels, as follows: Figure 8 and Figure 9 As shown. An input displacement of 10 μm is applied to the input end of the microclamp. Figure 8 Without fixing bolt 7 installed at the fulcrum, jaw 9 achieves clamping action, and the total displacement amplification ratio is 20.7; Figure 9 A fixing bolt 7 is installed at the fulcrum, and the jaws 9 open, achieving a total displacement amplification ratio of 11.6. Simulation results show that the single-drive piezoelectric micro-gripper simultaneously achieves both jaw opening and closing actions, verifying the rationality of the invention.

[0037] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A single-drive piezoelectric micro clamp with an opening and closing mechanism, characterized in that: It includes a composite rhomboid amplification mechanism (4), a lever amplification mechanism (5), a parallelogram mechanism (6), and a mode conversion block (8). The composite rhomboid amplification mechanism (4) is symmetrically arranged and connected to the lever amplification mechanism (5) and the parallelogram mechanism (6) from the inside to the outside on the left and right sides. The output ends of the two parallelogram mechanisms (6) are symmetrically connected to the two clamping parts of the jaws (9). The composite rhomboid amplification mechanism (4), the lever amplification mechanism (5), and the parallelogram mechanism (6) are all installed on the base (1) by fixing bolts (7). The fulcrum of the two lever amplification mechanisms (5) is externally connected to a mode conversion block (8) that can be detachably connected to the base (1). By changing the connection state between the mode conversion block (8) and the base (1), the micro clamp can be a two-stage amplification mechanism or a three-stage amplification mechanism, and then the jaws (9) can complete the clamping or opening action.

2. The opening and closing single-drive piezoelectric micro clamp according to claim 1, characterized in that: The composite rhomboid amplification mechanism (4) includes a movable end (401), a fixed end (403) and two amplification units (402); the two amplification units (402) are symmetrically connected between the movable end (401) and the fixed end (403), and the fixed end (403) is installed on the base (1) by fixing bolts (7).

3. The opening and closing single-drive piezoelectric micro clamp according to claim 2, characterized in that: Each of the amplification units (402) includes an output rod (4021) and four amplification rods (4022); the four amplification rods (4022) are divided into two groups, the output rods (4021) are located in the middle of the two groups of amplification rods (4022), one end of each amplification rod (4022) is connected to the output rod (4021), and the other end of each amplification rod (4022) is connected to the corresponding moving end (401) or fixed end (403).

4. The opening and closing single-drive piezoelectric micro clamp according to claim 3, characterized in that: The piezoelectric actuator (3) is placed between the two amplification units (402) of the composite rhombic amplification mechanism (4). The piezoelectric actuator (3) is fixed to the fixed end (403) of the composite rhombic amplification mechanism (4) by a pre-tightening bolt (2). The output end of the piezoelectric actuator (3) is connected to the moving end (401) of the composite rhombic amplification mechanism (4).

5. The opening and closing single-drive piezoelectric micro clamp according to claim 1, characterized in that: The main body of the lever amplification mechanism (5) adopts a rod-shaped structure. The input end of the lever amplification mechanism (5) is flexibly connected to the middle of the amplification unit (402) of the composite rhomboid amplification mechanism (4). The output end of the lever amplification mechanism (5) is flexibly connected to the parallelogram mechanism (6). The fulcrum position of the lever amplification mechanism (5) is flexibly connected to the mode conversion block (8).

6. The opening and closing single-drive piezoelectric micro clamp according to claim 1, characterized in that: The mode conversion block (8) has a threaded hole and is detachably connected to the base (1) by a fixing bolt (7).

7. The opening and closing single-drive piezoelectric micro clamp according to claim 1, characterized in that: The two clamping parts of the jaws (9) are symmetrically arranged on the left and right, and the two clamping parts are flexibly connected to the output end of the corresponding parallelogram mechanism (6).

8. A method of using an openable single-drive piezoelectric micro clamp, characterized in that: Includes the following steps: The pre-tightening bolt (2) fixes the piezoelectric actuator (3) inside the composite rhomboid amplification mechanism (4), and the fixing bolt (7) fixes the piezoelectric micro clamp on the base (1). After the piezoelectric actuator (3) is energized, it generates a vertical thrust. When the mode conversion block (8) is not installed with the fixing bolt (7), the micro clamp is a secondary amplification mechanism. The composite rhomboid amplification mechanism (4) directly drives the parallelogram mechanism (6) to move, thereby completing the clamping action of the jaws (9). When the mode conversion block (8) is installed with the fixing bolt (7), the micro clamp is a three-stage amplification mechanism. The composite rhomboid amplification mechanism (4) drives the lever amplification mechanism (5) to move, and the lever amplification mechanism (5) drives the parallelogram mechanism (6) to move, thereby completing the opening action of the jaws (9).

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