Asymmetric bridge amplification mechanism and stick-slip driver

Abstract

The utility model discloses an asymmetric bridge type amplification mechanism and stick -slip driver, asymmetric bridge type amplification mechanism includes input end head, output end head and hinge component, hinge component is located between input end head and output end head, including array distribution's first hinge unit, second hinge unit, third hinge unit and fourth hinge unit, first hinge unit and second hinge unit are spaced apart distribution along the second direction, and are connected with output end head respectively, first hinge unit includes two leaf type flexible hinges spaced apart distribution along the second direction, and second hinge unit includes a first arc shape flexible hinge, third hinge unit is located in the one end of first hinge unit away from output end head, and is connected with input end head, including a second arc shape flexible hinge, fourth hinge unit is located in the one end of second hinge unit away from output end head, and is connected with input end head, including a third arc shape flexible hinge, like this, has the stiffness difference of left and right asymmetry, improves the amplification ratio.

Description

Technical Field

[0001] This utility model relates to the field of micro precision drive technology, specifically to an asymmetric bridge amplification mechanism and a stick-slip actuator. Background Technology

[0002] With the continuous advancement of micro- and nano-manipulation and precision positioning technologies, the demand for high-performance drive devices in fields such as microelectromechanical systems (MEMS), biomedical engineering, optical alignment, and semiconductor manufacturing is becoming increasingly prominent. Stick-slip actuators, as a driving method combining high resolution and a large range of motion, have become one of the key technologies for achieving nanoscale positioning. Their performance directly determines the positioning accuracy, response speed, and motion stability of precision equipment. Currently, domestic and international research focuses on innovation in drive structures, optimization of control strategies, and improvement of friction interface characteristics, aiming to further enhance the output performance of actuators and their ability to adapt to complex working conditions.

[0003] In the structural design of drive devices, bridge amplifiers are widely used due to their compact structure and high displacement amplification ratio to enhance the output displacement and force of piezoelectric ceramics. From the traditional symmetrical bridge mechanism, various improved bridge configurations have gradually developed, and different structural forms have a significant impact on the stepping performance, stiffness, and dynamic response of the driver. However, bridge amplifiers with flexible hinges have an amplification limit due to their inherent characteristics; that is, for specific structural parameters, the amplification factor of a bridge amplifier is limited. This drawback greatly restricts the application range of bridge amplifiers. Utility Model Content

[0004] The main objective of this invention is to propose an asymmetric bridge amplification mechanism and a stick-slip actuator, which aims to solve the aforementioned problems.

[0005] To achieve the above objectives, this utility model proposes an asymmetric bridge amplification mechanism for use in a stick-slip actuator, comprising: The input terminal is used for connection to the piezoelectric ceramic drive of the stick-slip actuator; An output terminal is provided for connection to the drive foot of the stick-slip actuator and is spaced apart from the input terminal in a first direction; and, A hinge assembly, disposed between the input end and the output end, includes an array of first hinge units, second hinge units, third hinge units, and fourth hinge units. The first hinge units and the second hinge units are spaced apart along a second direction and are respectively connected to the output end. The first hinge unit includes two leaf-shaped flexible hinges spaced apart along the second direction. The second hinge unit includes a first arc-shaped flexible hinge. The third hinge unit is disposed at the end of the first hinge unit away from the output end and is connected to the input end, including a second arc-shaped flexible hinge. The fourth hinge unit is disposed at the end of the second hinge unit away from the output end and is connected to the input end, including a third arc-shaped flexible hinge. Wherein, the first direction and the second direction are perpendicular to each other in the horizontal plane.

[0006] Optionally, the first, second, and third arc-shaped flexible hinges each include a central rigid block and two hinge heads. The two hinge heads are located at both ends of the central rigid block in the first direction. Each hinge head has a groove on one side wall in the second direction, and the inner wall of the groove is elliptical. The groove openings of the two hinge heads of each arc-shaped flexible hinge are arranged opposite each other.

[0007] Optionally, the second arc-shaped flexible hinge and the third arc-shaped flexible hinge are symmetrically arranged along a first line of symmetry, which extends along the first direction; The first arc-shaped flexible hinge and the third arc-shaped flexible hinge are symmetrically arranged along the second line of symmetry, and the first line of symmetry extends along the second direction.

[0008] Optionally, the first hinge unit, the second hinge unit, and the third hinge unit are connected in series and in parallel with the fourth hinge unit.

[0009] This utility model also provides a stick-slip actuator, comprising: Motion; Two asymmetric bridge amplifier mechanisms are disposed on one side of the mover in the first direction, and are spaced apart along the second direction, and symmetrically arranged along a third line of symmetry extending along the first direction. The output end of each asymmetric bridge amplifier mechanism is connected to the mover; and... Two piezoelectric ceramics are disposed at the end of the asymmetric bridge amplification mechanism away from the mover. The two piezoelectric ceramics are driven and connected one-to-one with the output terminals of the two asymmetric bridge amplification mechanisms to drive the asymmetric bridge amplification mechanisms to move the mover. The asymmetric bridge amplification mechanism includes: The input terminal is used for connection to the piezoelectric ceramic drive of the stick-slip actuator; An output terminal is provided for connection to the drive foot of the stick-slip actuator and is spaced apart from the input terminal in a first direction; and, A hinge assembly, disposed between the input end and the output end, includes an array of first hinge units, second hinge units, third hinge units, and fourth hinge units. The first hinge units and the second hinge units are spaced apart along a second direction and are respectively connected to the output end. The first hinge unit includes two leaf-shaped flexible hinges spaced apart along the second direction. The second hinge unit includes a first arc-shaped flexible hinge. The third hinge unit is disposed at the end of the first hinge unit away from the output end and is connected to the input end, including a second arc-shaped flexible hinge. The fourth hinge unit is disposed at the end of the second hinge unit away from the output end and is connected to the input end, including a third arc-shaped flexible hinge. Wherein, the first direction and the second direction are perpendicular to each other in the horizontal plane.

[0010] Optionally, the moving element is a double-row crossed roller guide, including a fixed guide rail and a movable guide rail, wherein the movable guide rail can move relative to the fixed guide rail in the second direction; The output end of the asymmetric bridge amplification mechanism is connected to the movable guide rail via a driving foot.

[0011] Optionally, the stick-slip actuator further includes an outer frame on which the piezoelectric ceramic is mounted and connected to the asymmetric bridge amplification mechanism.

[0012] Optionally, the outer frame is made of aluminum alloy.

[0013] Optionally, the outer frame is manufactured using wire electrical discharge machining (EDM).

[0014] In the technical solution of this utility model, among the four hinge units, only the first hinge unit has two leaf-shaped flexible hinges, while the other hinge units, namely the second hinge unit, the third hinge unit, and the fourth hinge unit, each have an arc-shaped flexible hinge. This increases the longitudinal stiffness at the first hinge unit and helps to reduce the longitudinal stiffness at the other hinge units, so that the asymmetric bridge amplification mechanism has an asymmetric stiffness difference between the left and right sides, thereby improving the amplification ratio. It can provide a larger single-step stroke with a smaller amplification ratio, thus enabling the stick-slip actuator using this asymmetric bridge amplification mechanism to obtain a larger output displacement and accuracy. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 A top view of an embodiment of the asymmetric bridge amplification mechanism provided by this utility model; Figure 2 for Figure 1 A schematic diagram of the first arc-shaped flexible hinge in the middle; Figure 3 for Figure 1 A top view of an embodiment of a stick-slip actuator; Figure 4 for Figure 3 A partial structural diagram of a medium-speed stick-slip actuator; Figure 5 for Figure 3 Simulation diagram of a medium-speed stick-slip actuator; Figure 6 This is a schematic diagram of a traditional symmetrical bridge amplification mechanism. Figure 7 for Figure 6 A schematic diagram of a medium-flexible hinge.

[0017] Explanation of icon numbers:

[0018] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0022] In the structural design of drive devices, bridge amplifiers are widely used due to their compact structure and high displacement amplification ratio to enhance the output displacement and force of piezoelectric ceramics. From the traditional symmetrical bridge mechanism, various improved bridge configurations have gradually developed, and different structural forms have a significant impact on the stepping performance, stiffness, and dynamic response of the driver. However, bridge amplifiers with flexible hinges have an amplification limit due to their inherent characteristics; that is, for specific structural parameters, the amplification factor of a bridge amplifier is limited. This drawback greatly restricts the application range of bridge amplifiers.

[0023] In view of this, the present invention provides an asymmetric bridge amplification mechanism 100 for use in a stick-slip actuator 1000. Figure 1 and Figure 2 An embodiment of the asymmetric bridge amplification mechanism 100 provided by this utility model.

[0024] Please see Figure 1The asymmetric bridge amplification mechanism 100 includes an input terminal 1, an output terminal 2, and a hinge assembly. The input terminal 1 is used for driving connection with the piezoelectric ceramic 300 of the stick-slip actuator 1000; the output terminal 2 is used for connecting with the driving foot of the stick-slip actuator 1000 and is spaced apart from the input terminal 1 in a first direction; the hinge assembly is disposed between the input terminal 1 and the output terminal 2, and includes an array of first hinge units, second hinge units, third hinge units, and fourth hinge units, the first hinge units and the second hinge units being spaced apart along a second direction, and... The first hinge unit, which is connected to the output end 2, includes two leaf-shaped flexible hinges 3 spaced apart along the second direction. The second hinge unit includes a first arc-shaped flexible hinge 4. The third hinge unit is located at the end of the first hinge unit away from the output end 2 and is connected to the input end 1. It includes a second arc-shaped flexible hinge 5. The fourth hinge unit is located at the end of the second hinge unit away from the output end 2 and is connected to the input end 1. It includes a third arc-shaped flexible hinge 6. The first direction and the second direction are perpendicular to each other in the horizontal plane.

[0025] In this utility model's technical solution, among the four hinge units, only the first hinge unit has two leaf-shaped flexible hinges 3, while the other hinge units, namely the second, third, and fourth hinge units, each have one arc-shaped flexible hinge. This increases the longitudinal stiffness at the first hinge unit and helps reduce the longitudinal stiffness at the other hinge units, giving the asymmetric bridge amplification mechanism 100 an asymmetric stiffness difference, thereby increasing the amplification ratio. It can provide a larger single-step stroke with a smaller amplification ratio, thus enabling the stick-slip actuator 1000 using this asymmetric bridge amplification mechanism 100 to achieve greater output displacement and accuracy compared to traditional symmetrical bridge amplification mechanisms (such as...). Figure 6 and Figure 7 (As shown) is more in line with the characteristics and requirements of the stick-slip actuator 1000.

[0026] For further details, please refer to Figure 1 and Figure 2 The first arc-shaped flexible hinge 4, the second arc-shaped flexible hinge 5, and the third arc-shaped flexible hinge 6 each include a central rigid block 41 and two hinge heads 42. The two hinge heads 42 are located at both ends of the central rigid block 41 in the first direction. Each hinge head 42 has a groove 421 on one side wall in the second direction, and the inner wall of the groove 421 is elliptical. The groove openings of the grooves 421 of the two hinge heads 42 of each arc-shaped flexible hinge are arranged opposite each other.

[0027] Thus, the inner wall of the groove 421 is set in an elliptical arc shape, which can reduce the stiffness of the rigid block 41 in the middle of the flexible hinge, increase the force it can bear, reduce the force on the hinge heads 42 at both ends of the flexible hinge, reduce stress concentration to a certain extent, and further improve the stiffness difference between the two ends of the asymmetric bridge amplification mechanism 100 in the second direction, thereby improving the lateral displacement output of the driving foot of the stick-slip actuator 1000 to a certain extent.

[0028] For details, please refer to Figure 1 The second arc-shaped flexible hinge 5 and the third arc-shaped flexible hinge 6 are symmetrically arranged along a first line of symmetry, which extends along the first direction; the first arc-shaped flexible hinge 4 and the third arc-shaped flexible hinge 6 are symmetrically arranged along a second line of symmetry, which extends along the second direction.

[0029] Specifically, the first hinge unit, the second hinge unit, and the third hinge unit are connected in series and in parallel with the fourth hinge unit.

[0030] For details, please refer to Figure 1 In one embodiment of this utility model, both the input terminal 1 and the output terminal 2 are arranged in a strip shape.

[0031] This utility model also provides a stick-slip actuator 1000, please refer to [link / reference]. Figure 3 and Figure 4 The stick-slip actuator 1000 includes a mover 200, two asymmetric bridge amplification mechanisms 100, and two piezoelectric ceramics 300. The two asymmetric bridge amplification mechanisms 100 are located on one side of the mover 200 in the first direction and are spaced apart along the second direction, and are symmetrically arranged along a third symmetry line, which extends along the first direction. The output terminal 2 of each asymmetric bridge amplification mechanism 100 is connected to the mover 200. The two piezoelectric ceramics 300 are located at the end of the asymmetric bridge amplification mechanism 100 away from the mover 200, and are driven to drive the asymmetric bridge amplification mechanism 100 to move the mover 200.

[0032] In this utility model's technical solution, by inputting voltage signals to the two piezoelectric ceramics 300, expansion occurs based on the piezoelectric effect. The piezoelectric ceramics 300 drive the mover 200 to generate displacement through the asymmetric bridge mechanism. Utilizing the asymmetric stiffness of the asymmetric bridge mechanism, and by adjusting the position of the piezoelectric ceramics from inside the bridge amplification mechanism to outside it, the advantage of the asymmetric stiffness of the asymmetric bridge mechanism can be maximized. This results in the output displacement and amplification ratio being highly concentrated in the second direction (i.e., the X-axis direction). Furthermore, when the asymmetric bridge mechanism drives the mover 200, it can provide a large single-step stroke with a small amplification ratio, thereby enabling the stick-slip actuator 1000 to obtain a large output displacement and accuracy. Moreover, the two asymmetric bridge amplification mechanisms 100 are symmetrically arranged, enabling the stick-slip actuator 1000 to achieve single-degree-of-freedom bidirectional displacement.

[0033] It should be noted that the above-mentioned stick-slip actuator 1000 adopts the asymmetric bridge amplification mechanism 100 as described above. That is, the stick-slip actuator 1000 has all the technical features of all embodiments of the above-mentioned asymmetric bridge amplification mechanism 100, and thus has all the technical effects brought about by all the above-mentioned technical features. They will not be described in detail here.

[0034] For further details, please refer to Figure 3 and Figure 4 The mover 200 is a double-row crossed roller guide rail, including a fixed guide rail 210 and a movable guide rail 220. The movable guide rail 220 can move relative to the fixed guide rail 210 in the second direction. The output end 2 of the asymmetric bridge amplification mechanism 100 is connected to the movable guide rail 220 via a driving foot. That is, the mover 200 is the moving end of the stick-slip actuator 1000, the movable guide rail 220 is used to connect to the target drive platform, and the fixed guide rail 210 is threadedly connected to the vibration isolation platform.

[0035] For details, please refer to Figure 3 and Figure 4 The stick-slip actuator 1000 also includes an outer frame 400 on which the piezoelectric ceramic 300 is mounted and connected to the asymmetric bridge amplification mechanism 100. In other words, the outer frame 400 serves as the fixed end of the stick-slip actuator 1000. More specifically, the outer frame 400 has multiple threaded holes for fixing it to the vibration isolation platform using screws.

[0036] Furthermore, the outer frame 400 is made of aluminum alloy. More specifically, in one embodiment of this utility model, the outer frame 400 is made of AL7075-T6 material.

[0037] Specifically, the outer frame 400 is manufactured using wire electrical discharge machining (EDM). It should be noted that wire electrical discharge machining is an existing processing technology and will not be described in detail here.

[0038] Specifically, the outer frame 400 is provided with pre-tightening bolts corresponding to the piezoelectric ceramic 300 for pre-tightening the piezoelectric ceramic 300.

[0039] It should be noted that in this invention, a single piezoelectric ceramic 300 drives the actuator 200 to move in a single degree of freedom, i.e., unidirectional motion in the second direction (X-axis direction). For details, please refer to [link to relevant documentation]. Figure 5 Driving the left piezoelectric ceramic 300 will cause the mover 200 to move in the positive X-axis direction, and driving the right piezoelectric ceramic 300 will cause the mover 200 to move in the negative X-axis direction.

[0040] For details, please refer to Figure 5 The motion mechanism of the stick-slip actuator 1000 (taking the movement of the mover 200 in the positive X-axis direction as an example) is as follows: In the initial state, the two drive feet on the left side are in contact with the mover 200 with an initial clamping force due to the pre-tightening bolt.

[0041] A slowly increasing voltage signal is applied to the left piezoelectric ceramic 300, causing it to slowly elongate. The stick-slip actuator 1000 is in a driving state, and the driving foot drives the mover 200 to move slowly in the positive direction of the X-axis through static friction. When the voltage signal reaches its maximum value, the driving foot reaches its maximum parasitic displacement, i.e., the step stroke.

[0042] In the retracted state, the voltage signal rapidly drops from its maximum value to zero, causing the piezoelectric ceramic 300 and the entire mechanism to quickly retract to their initial state. Due to the inertia of the mover 200, sliding friction along the negative X-axis acts on the mover 200, resulting in retracted displacement. The drive foot releases the mover 200 as the piezoelectric ceramic 300 retracts, which helps reduce sliding friction and thus suppresses retracted movement.

[0043] The above steps constitute a cycle, and the large stroke drive of the X-axis is achieved by continuously alternating between the viscous phase of slow forward motion and the sliding phase of rapid backward motion. This is the coarse motion mode of the stick-slip actuator 1000.

[0044] After approximate positioning in coarse motion mode, precise positioning can be achieved in fine motion mode. In fine motion mode, the stick-slip actuator 1000 is always in the driving state, accurately positioning within the maximum step range, thus achieving high precision and resolution.

[0045] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. An asymmetric bridge amplification mechanism used in a stick-slip actuator, characterized in that, The asymmetric bridge amplification mechanism includes: The input terminal is used for connection to the piezoelectric ceramic drive of the stick-slip actuator; An output terminal is provided for connection to the drive foot of the stick-slip actuator and is spaced apart from the input terminal in a first direction; and, A hinge assembly, disposed between the input end and the output end, includes an array of first hinge units, second hinge units, third hinge units, and fourth hinge units. The first hinge units and the second hinge units are spaced apart along a second direction and are respectively connected to the output end. The first hinge unit includes two leaf-shaped flexible hinges spaced apart along the second direction. The second hinge unit includes a first arc-shaped flexible hinge. The third hinge unit is disposed at the end of the first hinge unit away from the output end and is connected to the input end, including a second arc-shaped flexible hinge. The fourth hinge unit is disposed at the end of the second hinge unit away from the output end and is connected to the input end, including a third arc-shaped flexible hinge. Wherein, the first direction and the second direction are perpendicular to each other in the horizontal plane.

2. The asymmetric bridge amplification mechanism as described in claim 1, characterized in that, The first, second, and third arc-shaped flexible hinges each include a central rigid block and two hinge heads. The two hinge heads are located at both ends of the central rigid block in the first direction. Each hinge head has a groove on one side wall in the second direction, and the inner wall of the groove is elliptical. The groove openings of the two hinge heads of each arc-shaped flexible hinge are arranged opposite each other.

3. The asymmetric bridge amplification mechanism as described in claim 1, characterized in that, The second arc-shaped flexible hinge and the third arc-shaped flexible hinge are symmetrically arranged along a first line of symmetry, which extends along the first direction. The first arc-shaped flexible hinge and the third arc-shaped flexible hinge are symmetrically arranged along the second line of symmetry, and the first line of symmetry extends along the second direction.

4. The asymmetric bridge amplification mechanism as described in claim 1, characterized in that, The first hinge unit, the second hinge unit, and the third hinge unit are connected in series and in parallel with the fourth hinge unit.

5. A stick-slip actuator, characterized in that, The stick-slip actuator includes: Motion; Two asymmetric bridge amplifier mechanisms as described in any one of claims 1-4 are disposed on one side of the mover in the first direction, and are spaced apart along the second direction, and are symmetrically arranged along a third line of symmetry extending along the first direction; the output end of each of the asymmetric bridge amplifier mechanisms is connected to the mover; and, Two piezoelectric ceramics are disposed at the end of the asymmetric bridge amplification mechanism away from the mover. The two piezoelectric ceramics are connected to the output terminals of the two asymmetric bridge amplification mechanisms in a one-to-one driving manner, so as to drive the asymmetric bridge amplification mechanism to move the mover.

6. The stick-slip actuator as described in claim 5, characterized in that, The moving element is a double-row crossed roller guide rail, including a fixed guide rail and a movable guide rail, wherein the movable guide rail can move relative to the fixed guide rail in the second direction; The output end of the asymmetric bridge amplification mechanism is connected to the movable guide rail via a driving foot.

7. The stick-slip actuator as described in claim 5, characterized in that, The stick-slip actuator also includes an outer frame on which the piezoelectric ceramic is mounted and connected to the asymmetric bridge amplification mechanism.

8. The stick-slip actuator as claimed in claim 7, characterized in that, The outer frame is made of aluminum alloy.

9. The stick-slip actuator as claimed in claim 7, characterized in that, The outer frame is manufactured using wire electrical discharge machining (EDM).

Images