A multi-layer inchworm drive for cross-scale high-speed nanomotion

Abstract

The application provides a multi-layer inchworm driver for cross-scale high-speed nanometer movement, and a multi-layer flexible clamping switching unit is arranged; by controlling a clamping piezoelectric ceramic and a driving piezoelectric ceramic, symmetrical switching of normally closed and normally open clamping can be realized, incomplete clamping switching caused by uneven stress of a clamping foot is avoided, and therefore the single-step effective displacement amount is improved, and the speed is improved; and a single clamping piezoelectric ceramic can drive the symmetrical flexible clamping mechanism to realize clamping switching, the number of piezoelectric ceramics used and the structural complexity are reduced, and the cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric precision drive technology, and in particular relates to a multilayer inchworm actuator for high-speed nano-motion across scales. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the continuous development of integrated circuit equipment, silicon photonics, and micromanipulation, the requirements for cross-scale nanoscale motion platforms are becoming increasingly stringent. In particular, higher demands are being placed on the resolution, speed, and load capacity of cross-scale motion.

[0004] Positioning platforms with cross-scale motion range and nanometer-level resolution are generally piezoelectric driven, and can be classified into three types according to their driving principle: piezoelectric ultrasonic drive, piezoelectric stick-slip drive, and piezoelectric inchworm drive. Piezoelectric ultrasonic drive utilizes the inverse piezoelectric effect of piezoelectric ceramic elements to excite ultrasonic vibrations of the stator, and uses the friction between the stator and mover to convert the micro-amplitude vibration of the stator into macroscopic motion of the mover or directly drive the load. It has advantages such as large driving force and high speed, but its low driving resolution and difficulty in speed adjustment limit its application in high-precision positioning. Piezoelectric stick-slip drive is based on the law of conservation of momentum. By applying a special voltage signal, such as a sawtooth wave, to a stack of piezoelectric elements or two piezoelectric crystals, relative sliding displacement is generated between two mass blocks of different weights, thereby achieving stepping motion. The biggest advantage of stick-slip piezoelectric actuators is their relatively simple structure. As a single-input single-output system, their control logic is also relatively simple. However, they suffer from drawbacks in high-load and tracking control due to low load and motion backlash.

[0005] Piezoelectric inchworm actuators are designed by mimicking the stepping and peristaltic movement principle of inchworms in nature. They can achieve large stroke, high resolution and high load motion output. However, the designs mentioned so far are all complex in terms of drive structure and control logic, and the drive speed is limited due to incomplete clamping switching. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a multi-layer inchworm actuator for high-speed nano-motion across scales. The present invention achieves symmetrical switching between normally closed and normally open clamping positions by setting up a multi-layer flexible clamping switching unit, avoiding incomplete clamping switching caused by uneven force on the clamping feet, thereby increasing the effective displacement per step and achieving the purpose of increasing speed.

[0007] To achieve the above objectives, a first aspect of the present invention provides a multilayer inchworm actuator for high-speed nanomotion across scales, comprising: a multilayer flexible clamping switching unit, a composite flexible driving unit, and a moving guiding unit;

[0008] The multi-layer flexible clamping switching unit includes a symmetrical flexible clamping mechanism, a multi-layer symmetrical active clamping mechanism disposed within the symmetrical flexible clamping mechanism, and a clamping piezoelectric ceramic disposed on the active clamping mechanism; the input terminal of the clamping piezoelectric ceramic has a first voltage signal for controlling the left and right movement of the symmetrical flexible clamping mechanism.

[0009] The composite flexible driving unit includes a driving piezoelectric ceramic and an amplification mechanism; the driving piezoelectric ceramic is disposed inside the amplification mechanism, and the amplification mechanism is disposed above the symmetrical flexible clamping mechanism; the input terminal of the driving piezoelectric ceramic has a second voltage signal for controlling the up and down movement of the amplification mechanism;

[0010] The movable guide unit and the symmetrical flexible clamping mechanism can switch contact.

[0011] The above one or more technical solutions have the following beneficial effects:

[0012] In this invention, the multi-layer flexible clamping switching unit, by controlling the clamping piezoelectric ceramic and driving the piezoelectric ceramic, can achieve symmetrical switching between normally closed and normally open clamping, avoiding incomplete clamping switching caused by uneven force on the clamping feet, thereby increasing the effective displacement per step and achieving the purpose of increasing speed; moreover, a single clamping piezoelectric ceramic can drive the symmetrical flexible clamping mechanism to achieve clamping switching, reducing the number of piezoelectric ceramics used and the structural complexity, and reducing costs.

[0013] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0015] Figure 1 This is a schematic diagram of the overall system of the multi-layer inchworm actuator in Embodiment 1 of the present invention;

[0016] Figure 2 This is a schematic diagram of the symmetrical flexible clamping mechanism of the multi-layer inchworm actuator in Embodiment 1 of the present invention;

[0017] Figure 3 This is a schematic diagram of the active clamping mechanism of the multilayer inchworm actuator in Embodiment 1 of the present invention;

[0018] Figure 4 This is a schematic diagram of the lever amplification mechanism of the multi-layer inchworm actuator in Embodiment 1 of the present invention;

[0019] Figure 5 This is a schematic diagram of the triangular amplification mechanism of the multilayer inchworm actuator in Embodiment 1 of the present invention;

[0020] Figure 6 This is a schematic diagram of the flexible guide plate of the multilayer inchworm actuator in Embodiment 1 of the present invention;

[0021] Figure 7 This is a schematic diagram of the driving principle of the multilayer inchworm actuator in Embodiment 1 of the present invention;

[0022] In the diagram, 1. Drive piezoelectric ceramic; 2. Lever amplification mechanism; 201. M2 threaded countersunk hole; 202. Arc-shaped notch hinge; 203. Lever arm; 204. T-shaped notch groove; 3. Symmetrical flexible clamping mechanism; 301. Symmetrical clamping foot; 302. Guide leaf spring; 303. Fixed base; 304. Symmetrical moving frame; 305. Positioning groove; 306. Fixed countersunk hole; 307. M2 threaded hole; 4. Precision fine-tuning unit; 5. Micrometer head; 6. Active clamping mechanism; 601. Bridge-type positioning end face; 602. Bridge-type moving end; 603. Preloaded threaded hole; 6 04. Active clamping foot; 605. Bridge connecting block; 606. Connecting bridge arm; 607. First rectangular notch hinge; 608. First guide plate fixing and positioning groove; 7. Cross roller guide rail; 8. Triangular amplification mechanism; 801. Triangular amplification output end; 802. Rectangular clearance groove; 803. Second guide plate fixing and positioning groove; 804. T-shaped positioning pin; 805. Second rectangular notch hinge; 806. Triangular connecting arm; 9. Flexible guide plate; 901. Thin spring; 902. Positioning circular hole; 10. Stator base plate; 11. Clamping piezoelectric ceramic; 12. Mover base plate. Detailed Implementation

[0023] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0025] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0026] Example 1

[0027] This embodiment discloses a multilayer inchworm actuator for high-speed nanomotion across scales, comprising: a multilayer flexible clamping switching unit, a composite flexible driving unit, and a moving guiding unit;

[0028] The multi-layer flexible clamping switching unit includes a symmetrical flexible clamping mechanism, a multi-layer symmetrical active clamping mechanism disposed within the symmetrical flexible clamping mechanism, and a clamping piezoelectric ceramic disposed on the active clamping mechanism; the input terminal of the clamping piezoelectric ceramic has a first voltage signal for controlling the left and right movement of the symmetrical flexible clamping mechanism.

[0029] The composite flexible driving unit includes a driving piezoelectric ceramic and an amplification mechanism; the driving piezoelectric ceramic is disposed inside the amplification mechanism, and the amplification mechanism is disposed above the symmetrical flexible clamping mechanism; the input terminal of the driving piezoelectric ceramic has a second voltage signal for controlling the up and down movement of the amplification mechanism;

[0030] The movable guide unit and the symmetrical flexible clamping mechanism can switch contact.

[0031] like Figure 1 As shown, this embodiment of a multi-layer inchworm actuator for high-speed nano-motion across scales includes, from top to bottom and from right to left, a driving piezoelectric ceramic 1, a lever amplification mechanism 2, a symmetrical flexible clamping mechanism 3, a precision fine-tuning unit 4, a differential head 5, an active clamping mechanism 6, a cross roller guide 7, a triangular amplification mechanism 8, a flexible guide plate 9, a stator substrate 10, a clamping piezoelectric ceramic 11, and a mover substrate 12.

[0032] The multi-layer flexible clamping switching unit includes a symmetrical flexible clamping mechanism 3, an active clamping mechanism 6, and a clamping piezoelectric ceramic 11; the composite flexible driving unit includes a driving piezoelectric ceramic 1, a lever amplification mechanism 2, a triangular amplification mechanism 8, and a flexible guide plate 9; the moving guide unit includes a moving substrate 12, a stator substrate 10, and a cross roller guide rail 7.

[0033] In the moving guide unit, the moving base plate 12 is connected to the stator base plate 10 through the cross roller guide 7. The cross roller guide 7 is fixed to the moving base plate 12 and the stator base plate 10 respectively using hexagon socket screws. The upper surface of the moving base plate 12 is bonded with a wear-resistant ceramic base plate through high-strength epoxy adhesive, and switches to contact with the clamping foot. The clamping foot is made of wear-resistant ceramic material.

[0034] like Figure 2 As shown, in the multi-layer flexible clamping switching unit, the symmetrical flexible clamping mechanism 3 includes a fixed base 303, which is U-shaped. A double-layer guide structure is set inside the fixed base 303, and a positioning groove 305 is set between the double-layer guide structure. Two screw fixing through holes are evenly distributed in the middle of the positioning groove 305 for connecting and fastening the active clamping mechanism 6.

[0035] Specifically, the two layers of the double-layer guide structure are symmetrically equipped with four guide leaf springs 302. One end of the guide leaf spring 302 is connected to the symmetrical moving frame 304, and the symmetrical moving frames 304 are linked together. The other end of the guide leaf spring 302 is connected to the fixed base 303. A symmetrical clamping foot 301 is provided at the front end of the symmetrical moving frame 304. The fixed base 303 is provided with four fixed countersunk through holes 306 and M2 threaded holes 307 along the edge. The fixed countersunk through holes 306 and M2 threaded holes 307 are used to connect the precision fine-tuning unit 4 and the lever amplification mechanism 2, respectively.

[0036] The design of the double-layer symmetrical structure can achieve symmetrical application of clamping force, avoiding incomplete switching caused by uneven force during clamping switching.

[0037] In this embodiment, the driver body is mounted on the precision fine-tuning unit 4. The function of the precision fine-tuning unit 4 is to make minute adjustments to the clamping foot spacing, which is specifically achieved by a micro head in conjunction with the moving platform.

[0038] like Figure 3 As shown, the active clamping mechanism 6 is designed as a bridge-type enlarged structure. The active clamping mechanism 6 is inserted in the middle of the symmetrical flexible clamping mechanism 3. The bottom of the active clamping mechanism 6 is provided with a bridge-type positioning end face 601. The bridge-type positioning end face 601 is connected to the positioning groove 305 of the symmetrical flexible clamping mechanism 3 by screw positioning. The front part of the active clamping mechanism 6 is provided with a bridge-type moving end 602. The bridge-type moving end 602 is connected to the active clamping foot 604 in the form of a flexible plate. The active clamping foot 604 is provided with a first guide plate fixing positioning groove 608. The right end of the bridge-type moving end 602 is provided with a pre-tightening threaded hole 603. The pre-tightening threaded hole 603 is used to pre-tighten the clamping piezoelectric ceramic 11. The left end of the bridge-type moving end 602 is provided with a bridge-type connecting block 605. The bridge connecting block 605 is used to fix the clamping piezoelectric ceramic 11.

[0039] Specifically, connecting bridge arms 606 are respectively provided between the bridge connecting block 605 and the bridge moving end 602, and between the bridge connecting block 605 and the bridge positioning end face 601. One end of the connecting bridge arm 606 is connected to a first rectangular notch hinge 607. The connecting bridge arm 606 is connected to the bridge connecting block 605 through the first rectangular notch hinge 607. The other end of the connecting bridge arm 606 is connected to the bridge moving end 602 or the bridge positioning end face 601, thereby forming a structural closed loop.

[0040] The active clamping mechanism 6 utilizes a bridge-type flexible amplification mechanism in conjunction with the clamping piezoelectric ceramic 11 to achieve the displacement output of the active clamping foot 604, thereby completing the switching between normally closed and normally open clamping feet. When voltage is applied to the clamping piezoelectric ceramic 11, it extends, driving the bridge-type moving end 602 of the bridge-type flexible amplification mechanism to output displacement, further pushing the active clamping foot 604 to contact the moving substrate 12, and generating a reaction force to push the symmetrical moving frame 304 to move in the opposite direction, causing the symmetrical clamping foot 301 to separate from the moving substrate 12, thus completing the switching between normally closed and normally open clamping feet.

[0041] like Figure 4 As shown, the lever amplification mechanism 2 is designed with a symmetrical structure, including a first arm and lever arms 203 symmetrically arranged at both ends of the first arm. Four M2 threaded countersunk holes 201 are evenly arranged on the first arm. The first arm is connected to the lever arms 203 via an arc-shaped notch hinge 202. A T-shaped notch 204 is provided at the top of the lever arms 203. The driving piezoelectric ceramic 1 is installed between the symmetrical lever arms 203, approximately one-third of the way from the first arm.

[0042] The lever amplification mechanism 2 utilizes two symmetrical sets of lever mechanisms in conjunction with piezoelectric ceramics to achieve the first-stage displacement amplification of the composite flexible drive unit.

[0043] like Figure 5 As shown, the triangular amplification mechanism 8 is designed with a symmetrical structure. It is the second-stage amplification mechanism of the composite flexible drive unit and is installed in series at the end of the lever amplification mechanism. Specifically, the triangular amplification mechanism 8 includes a triangular amplification output end 801 located in the middle, and T-shaped positioning pins 804 are symmetrically arranged at both ends of the triangular amplification mechanism 8. The T-shaped positioning pins 804 are fitted into the T-shaped notch 204 in the lever amplification mechanism 2.

[0044] Specifically, a second rectangular notch hinge 805 and a triangular connecting arm 806 are provided between the triangular amplifier output end 801 and the T-shaped positioning pin 804. One end of the triangular connecting arm 806 is provided with the second rectangular notch hinge 805, and the triangular connecting arm 806 is connected to the T-shaped positioning pin 804 through the second rectangular notch hinge 805. The other end of the triangular connecting arm 806 is connected to the triangular amplifier output end 801. A rectangular clearance groove 802 is provided on one side of the middle of the triangular amplifier output end 801. Second guide plate fixing and positioning grooves 803 are symmetrically arranged on both sides of the rectangular clearance groove 802. The second guide plate fixing and positioning grooves 803 are connected to the flexible guide plate 9 to ensure its positional accuracy.

[0045] The rectangular clearance groove 802 serves to provide clearance for the symmetrical clamping feet 301 of the symmetrical flexible clamping mechanism 3. To achieve a symmetrical and centered arrangement of the multi-layer compact structure and the clamping feet, the symmetrical clamping feet 301 of the symmetrical flexible clamping mechanism 3 are arranged in the middle of the rectangular clearance groove 802, and flexible guide plates 9 are arranged on both sides.

[0046] Among them, such as Figure 6 As shown, the flexible guide plate 9 is a leaf spring structure with a thin spring plate 901 in the middle and positioning circular holes 902 at both ends. The flexible guide plate 9 consists of two symmetrically installed plates. The upper end of the flexible guide plate 9 is connected to the second guide plate fixing and positioning groove 803 at the output end of the triangular amplification mechanism, and the lower end of the flexible guide plate 9 is connected to the first guide plate fixing and positioning groove 608 of the active clamping mechanism 6. The plates are fastened with cross-head screws.

[0047] The delta amplification mechanism 8 and the lever amplification mechanism 2 are connected in series at a spatial angle of 90°. Positioning and fastening are achieved by inserting the T-shaped positioning pin 804 of the delta amplification mechanism 8 into the T-shaped notch 204 of the lever amplification mechanism 2. When a voltage is applied to the piezoelectric ceramic, it elongates, causing the T-shaped notch 204 of the lever amplification mechanism 2 to shift position. This displacement simultaneously pushes the T-shaped positioning pin 804 of the delta amplification mechanism 8, which then outputs displacement at the delta amplification output end 801. This displacement drives the active clamping foot 604 to move, and the movement is transmitted to the moving substrate 12 via friction, achieving single-step displacement drive.

[0048] In this embodiment, as Figure 7 As shown, the designed multi-layer inchworm actuator can achieve single-axis forward and reverse cross-scale nanometer-level motion. First, based on the connection and fixing relationships of each component, the mechanical components are installed and the piezoelectric ceramic is pre-tightened. By adjusting the differential head 5 of the precision fine-tuning unit, the symmetrical clamping foot 301 contacts the moving substrate 12 and is in a suitable pre-tightened state. The actuation can be achieved by following these steps:

[0049] Step 1: As Figure 7 As shown in Figure (1), from time t0 to t1, a ramp voltage is applied to the clamping piezoelectric ceramic 11, the clamping piezoelectric ceramic 11 elongates, and the active clamping mechanism 6 pushes the active clamping foot 604 to contact the moving substrate 12 and applies pressure, thereby pushing the symmetrical clamping foot 301 of the symmetrical flexible clamping mechanism 3 to separate from the moving substrate 12, and realizing the clamping foot switching.

[0050] Step 2: As Figure 7 As shown in Figure (2), from time t2 to t3, the clamping piezoelectric ceramic 11 maintains voltage Vmax, the active clamping foot 604 maintains clamping state, and a ramp voltage is applied to the driving piezoelectric ceramic 1 to drive the piezoelectric ceramic 1 to extend. In conjunction with the lever amplification mechanism and the triangular amplification mechanism, the active clamping foot 604 drives the moving sub-substrate 12 to move downward by a displacement Δx.

[0051] Step 3: As Figure 7As shown in Figure (3), from time t4 to t5, the driving piezoelectric ceramic 1 maintains a high voltage Vmax, the voltage applied to the clamping piezoelectric ceramic 11 decreases to 0V, the clamping piezoelectric ceramic 11 shrinks to its original length, the active clamping foot 604 separates, and the symmetrical clamping foot 301 closes, realizing the switching of the clamping foot.

[0052] Step 4: Figure 7 As shown in Figure (4), from time t6 to t7, the clamping switch is completed, the voltage applied to the driving piezoelectric ceramic 1 is reduced to 0V, the driving piezoelectric ceramic 1 retracts to its original length, and drives the active clamping foot 604 back to its initial position.

[0053] Based on the aforementioned driving principle, the multi-layer structure design effectively avoids asymmetry in clamping switching during steps 1 and 3, achieving rapid clamping switching. These four steps complete the single-step displacement Δx of the stacked inchworm actuator; repeating these steps enables long-stroke motion. The reverse driving principle is similar to the forward driving principle; rapid switching between forward and reverse motion can be achieved by changing the timing of the input voltage signal, and will not be elaborated further.

[0054] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0055] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A multilayer inchworm actuator for high-speed nanomotion across scales, characterized in that, include: Multi-layer flexible clamping switching unit, composite flexible drive unit and moving guide unit; The multi-layer flexible clamping switching unit includes a symmetrical flexible clamping mechanism, a multi-layer symmetrical active clamping mechanism disposed within the symmetrical flexible clamping mechanism, and a clamping piezoelectric ceramic disposed on the active clamping mechanism; the input terminal of the clamping piezoelectric ceramic has a first voltage signal for controlling the left and right movement of the symmetrical flexible clamping mechanism. The symmetrical flexible clamping mechanism includes a fixed base and a symmetrical moving frame. The symmetrical moving frame is arranged in layers within the fixed base, and a guide leaf spring is provided between the symmetrical moving frame and the fixed base. The active clamping mechanism is connected in the positioning groove formed by the symmetrical moving frame, the fixed base, and the guide leaf spring. The active clamping mechanism is a bridge-type amplified structure. A bridge-type positioning end face for connecting the symmetrical flexible clamping mechanism is provided at the bottom of the active clamping mechanism. A bridge-type moving end for connecting the active clamping foot is provided at the front end of the active clamping mechanism. Bridge-type connecting blocks for fixing the clamping piezoelectric ceramic are symmetrically arranged on both sides of the active clamping mechanism. The bridge-type connecting blocks are connected to connecting bridge arms via rectangular notch hinges, and the connecting bridge arms are connected to the bridge-type moving end or the bridge-type positioning end face. A first guide plate fixing and positioning groove is provided on the active clamping foot, and the first guide plate fixing and positioning groove is connected to the active clamping mechanism through a flexible guide plate; The composite flexible driving unit includes a driving piezoelectric ceramic and an amplification mechanism; the driving piezoelectric ceramic is disposed inside the amplification mechanism, and the amplification mechanism is disposed above the symmetrical flexible clamping mechanism; the input terminal of the driving piezoelectric ceramic has a second voltage signal for controlling the up and down movement of the amplification mechanism; The movable guide unit and the symmetrical flexible clamping mechanism can switch contact.

2. The multilayer inchworm actuator for high-speed nanomotion across scales as described in claim 1, characterized in that, A symmetrical clamping foot is provided at the front end of the symmetrical moving frame. The symmetrical clamping foot switches clamping position with the moving guide unit under the action of clamping piezoelectric ceramic.

3. The multilayer inchworm actuator for high-speed nanomotion across scales as described in claim 1, characterized in that, The amplification mechanism includes a lever amplification mechanism and a triangular amplification mechanism; the lever amplification mechanism includes symmetrical lever arms, the driving piezoelectric ceramic is installed between the symmetrical lever arms, and the end of the lever arm is provided with a T-shaped notch.

4. The multilayer inchworm actuator for high-speed nanomotion across scales as described in claim 3, characterized in that, The triangular amplification mechanism includes a triangular amplification output end and a T-shaped positioning pin. The T-shaped positioning pin is installed in conjunction with the T-shaped notch. One end of a triangular connecting arm is symmetrically connected to both sides of the triangular amplification output end. The other end of the triangular connecting arm is connected to one end of a rectangular notch hinge. The other end of the rectangular notch hinge is connected to the T-shaped positioning pin. A rectangular clearance groove is provided in the middle of the triangular amplification output end. Second guide plate fixing and positioning grooves are symmetrically provided on both sides of the rectangular clearance groove. The second guide plate fixing and positioning grooves are connected to the first guide plate fixing and positioning grooves through flexible guide plates.

5. The multilayer inchworm actuator for high-speed nanomotion across scales as described in claim 4, characterized in that, The flexible guide sheet includes a thin spring sheet and positioning circular holes disposed at both ends of the thin spring sheet.

6. The multilayer inchworm actuator for high-speed nanomotion across scales as described in claim 1, characterized in that, The active clamping foot is disposed in a rectangular clearance groove.

7. A multilayer inchworm actuator for high-speed nanomotion across scales as described in claim 1, characterized in that, The moving guide unit includes a moving base plate and a stator base plate, and the stator base plate and the moving base plate are connected by a cross roller guide rail.

Images