Piezoelectric stick-slip driver

Abstract

The piezoelectric stick-slip driver comprises a support assembly, a mover assembly and a stator assembly, the stator assembly comprises a connecting base, an asymmetric triangular hinge and a piezoelectric stack, the connecting base is connected with the support assembly through a connecting piece, the asymmetric triangular hinge is arranged between a moving piece and the connecting base, and the piezoelectric stack is arranged between the connecting piece and the connecting base. The gravity center position of the asymmetric triangular hinge is connected with the support assembly through a torsion hinge, one corner of the asymmetric triangular hinge faces the movable part and is provided with a driving foot, the driving foot is used for being connected with the movable part in a stick-slip mode, and the side edge of one edge of the asymmetric triangular hinge faces the connecting base and is connected with the connecting base through a stress hinge. And the piezoelectric stack applies thrust towards the positive direction of the Z axis to the stress hinge. The asymmetric triangular hinge accumulates force in the forward torsion process, so that the asymmetric triangular hinge can rapidly return in the reverse torsion process, the return distance of the movable part in the stick-slip motion process is reduced, and the effective displacement of the movable part is improved.

Description

Technical Field

[0001] The invention relates to the field of drive technology, in particular to a piezoelectric stick-slip drive. Background Art

[0002] Piezoelectric drive uses the inverse piezoelectric effect of piezoelectric materials to achieve nano-level motion control. It has the advantages of fast response, high precision, no electromagnetic interference, high vibration frequency and high force density. It has been widely used in various systems with nano-level positioning capabilities. Applying piezoelectric drive technology in the field of ultra-precision machining to ensure and improve the accuracy of ultra-precision machining has also become a core research direction of ultra-precision machining technology.

[0003] Stick-slip piezoelectric actuators are usually driven by asymmetric waveforms such as sawtooth waves, which produce stepping motion under the action of friction and inertia, and achieve a large working stroke through the stepping motion of the rotor / slider. Although the motion displacement of each step is relatively small, the accumulated displacement is theoretically infinite. In recent years, a large number of scientific research institutions at home and abroad have optimized the design of stick-slip piezoelectric actuators. However, the driving principle of the stick-slip actuator leads to an inherent backlash phenomenon, which greatly reduces the motion speed and accuracy. This limits the application of stick-slip actuators, thereby greatly limiting the application scope of stick-slip piezoelectric actuators. Summary of the invention

[0004] To this end, the present invention provides a piezoelectric stick-slip actuator, which can better solve the problem that the current stick-slip actuator has a large inherent retraction during the driving process and the problem that the structural deformation recovers slowly during the retraction process.

[0005] In order to solve the above technical problems, the present invention provides a piezoelectric stick-slip actuator, comprising: Bracket assembly, A movable member assembly comprises a guide member and a movable member, wherein the guide member is connected to the bracket assembly, the movable member is connected to the guide member, and the movable member moves under the guidance of the guide member; A stator assembly, comprising a connecting seat, an asymmetric triangular hinge and a piezoelectric stack, wherein the connecting seat is connected to the support assembly via a connecting piece, the asymmetric triangular hinge is arranged between the movable part and the connecting seat, the center of gravity of the asymmetric triangular hinge is connected to the support assembly via a torsion hinge, one of the corners of the asymmetric triangular hinge faces the movable part and is provided with a driving foot, the driving foot is used for a stick-slip connection with the movable part, one of the side edges of the asymmetric triangular hinge faces the connecting seat and is connected to the connecting seat via a force-bearing hinge, and the piezoelectric stack applies a thrust toward the positive direction of the Z axis to the force-bearing hinge; Wherein, when the piezoelectric stack is extended, the asymmetric triangular hinge can overcome the elastic force to perform positive twisting, and the driving foot is adhered to the movable part and drives the movable part to move; When the piezoelectric stack is shortened, the asymmetric triangular hinge is rapidly reversely twisted and reset under the drive of the elastic force, and the driving foot slides relative to the movable member.

[0006] Furthermore, the asymmetric triangular hinge includes a triangular frame, a torsion center portion and a support portion, the torsion center portion is located at the center of gravity of the triangular frame and is connected to the border of the triangular frame through the support portion, and the torsion center portion is connected to the bracket assembly through the torsion hinge.

[0007] Furthermore, the triangular frame includes a first frame, a second frame and a third frame which are connected end to end in sequence, the driving foot is arranged at the intersection of the first frame and the second frame, the first frame and the second frame are connected to the third frame through a flexible hinge part, and the support part is connected to the torsion center part through a flexible intersection part.

[0008] Furthermore, the torsion hinge is a rigid connector or an elastic connector.

[0009] Furthermore, the connecting seat is in a concave shape, including a groove bottom, two groove wall portions and a groove enclosed by the groove bottom and the groove wall portions, the two groove wall portions are arranged at a distance along the Y-axis direction and connected to the Z-axis positive direction side of the groove wall portions, the force-bearing hinge connects the notch positions of the two groove wall portions, and the piezoelectric stack is arranged in the groove.

[0010] Furthermore, the force-bearing hinge includes a first force-bearing part and a second force-bearing part, the first force-bearing part is connected to the asymmetric triangular hinge through a flexible hinge, the first force-bearing part is connected to the groove wall part through a flexible hinge, the second force-bearing part is connected to the first force-bearing part through a flexible hinge, the second force-bearing part moves under the guidance of the two groove wall parts, and the second force-bearing part bears the thrust of the piezoelectric stack.

[0011] Furthermore, the groove wall portion is connected to the groove bottom portion via a flexible hinge portion.

[0012] Furthermore, a pre-tightening gasket is provided between the piezoelectric stack and the bottom of the groove, and a pre-tightening bolt is connected to the bottom of the groove.

[0013] Furthermore, a friction layer is provided on the driving foot to enhance its friction force.

[0014] Furthermore, the guide member is a fixed guide rail, the movable member is a movable guide rail, and the fixed guide rail guides the movable guide rail to translate along the Y-axis direction.

[0015] The above technical solution of the present invention has the following advantages over the prior art: the piezoelectric stick-slip actuator of the present invention connects the center of gravity of the asymmetric triangular hinge with the bracket assembly, so that the asymmetric triangular hinge can store force during the forward torsion process, so that the asymmetric triangular hinge can quickly retreat during the reverse torsion, reducing the retreat distance of the moving part during the stick-slip motion process and increasing the effective displacement of the moving part. Compared with the prior art, the output speed of the present invention is greatly improved, the output efficiency is improved by 30%, and the displacement retreat rate is reduced by more than 80%. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] Figure 1 is an external schematic diagram of the piezoelectric stick-slip actuator of the present invention; Figure 2 It is a schematic diagram of the interior of the piezoelectric stick-slip actuator in the present invention; Figure 3 It is a structural schematic diagram of the bracket assembly in the present invention; Figure 4 It is a structural schematic diagram of the stator assembly in the present invention; Figure 5 It is a schematic diagram of the initial stage of the driving process of the piezoelectric stick-slip actuator in the present invention; Figure 6 It is a schematic diagram of the voltage rising stage of the driving process of the piezoelectric stick-slip actuator in the present invention; Figure 7 It is a schematic diagram of the separation stage of the driving process of the piezoelectric stick-slip actuator in the present invention; Figure 8 It is a schematic diagram of the voltage drop stage of the driving process of the piezoelectric stick-slip actuator in the present invention.

[0018] Description of the reference numerals in the specification: 1, bracket assembly; 11, housing; 111, support platform; 112, avoidance opening; 113, support column; 12, upper cover; 13, fixed connecting piece; 131, long groove; 2. mover assembly; 21. guide member; 22. movable member; 23. cross roller; 3. Stator assembly; 31. Connecting seat; 311. Slot bottom; 312. Slot wall; 32. Asymmetric triangular hinge; 321. Driving foot; 322. Triangular frame; 323. Torsion center; 324. Support; 33. Piezoelectric stack; 35. Connector; 36. Torsion hinge; 37. Force hinge; 371. First force-bearing part; 372. Second force-bearing part; 38. Preload gasket; 39. Preload bolt. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0020] See also Figures 1 to 4 As shown, one embodiment of the piezoelectric stick-slip actuator provided by the present invention.

[0021] Piezoelectric stick-slip actuators, including: Bracket assembly 1; The movable member assembly comprises a guide member 21 and a movable member 22, wherein the guide member 21 is connected to the bracket assembly 1, and the movable member 22 is connected to the guide member 21 and moves under the guidance of the guide member 21; A stator assembly, comprising a connection seat 31, an asymmetric triangular hinge 32 and a piezoelectric stack 33, wherein the connection seat 31 is connected to the bracket assembly 1 via a connecting member 35, the asymmetric triangular hinge 32 is arranged between the movable member 22 and the connection seat 31, the center of gravity of the asymmetric triangular hinge 32 is connected to the bracket assembly 1 via a torsion hinge 36, one of the corners of the asymmetric triangular hinge 32 faces the movable member 22 and is provided with a driving foot 321, one of the sides of the asymmetric triangular hinge 32 faces the connection seat 31 and is connected to the connection seat 31 via a force-bearing hinge 37, and the piezoelectric stack 33 is arranged on the negative Z-axis side of the asymmetric triangular hinge 32 and applies a thrust toward the positive Z-axis direction to the force-bearing hinge 37; When the piezoelectric stack 33 is extended, the asymmetric triangular hinge 32 can overcome the elastic force to perform positive twisting, the driving foot 321 is adhered to the movable member 22, and the driving foot 321 drives the movable member 22 to move; When the piezoelectric stack 33 is shortened, the asymmetric triangular hinge 32 is rapidly reversely twisted and reset under the drive of the elastic force, and the driving foot 321 slides relative to the movable member 22 .

[0022] The positive projection of the asymmetric triangular hinge 32 in the plane perpendicular to the X-axis direction is an asymmetric triangle. Due to the asymmetric characteristics, the stiffness distribution is non-uniform during the torsion process. According to the rotation characteristics of the asymmetric triangular hinge, this design structure can convert the Z-axis compression deformation of the piezoelectric stack 33 into torsion deformation to generate displacement in other directions, and drive the movable part 22 to move through the stick-slip characteristics. The asymmetric triangular hinge 32 is easy to strengthen rigidity, support and provide mechanical strength, and the hinge structure designed inside can distribute the applied force, thereby achieving torsion.

[0023] The connecting seat 31 is relatively fixed to the bracket assembly 1 , and the torsion hinge 36 cannot completely limit the torsion of the asymmetric triangular hinge 32 , but will form a resistance.

[0024] Specifically, the asymmetric triangular hinge 32 is provided with the driving foot 321 near the maximum inner angle, and the asymmetric triangular hinge 32 is connected to the connecting seat 31 near the minimum inner angle. The three inner angles of the asymmetric triangular hinge 32 are 90 degrees, 60 degrees and 30 degrees respectively.

[0025] When working, a sawtooth wave voltage signal with a period of T is used as the input voltage waveform, the excitation voltage amplitude is V, and the symmetry is D. The piezoelectric stack 33 is deformed in the Z-axis direction by applying a sawtooth wave signal and an isosceles triangle wave signal to both ends of the piezoelectric stack 33, and the deformation acts on the driving structure part. Based on the characteristics of the rotation of the asymmetric triangle hinge, the movable part 22 is driven to move by the stick-slip principle. Among them, T ranges from 0.001 to 1s, V ranges from 60 to 120 V, and the symmetry D can be 50 to 99.999%.

[0026] In this embodiment, the asymmetric triangular hinge 32 includes a triangular frame 322, a torsion center portion 323 and a support portion 324. The torsion center portion 323 is arranged at the center of gravity of the triangular frame 322. The support portion 324 connects the torsion center portion 323 and the border of the triangular frame 322. The torsion center portion 323 is connected to the bracket assembly 1 through the torsion hinge 36.

[0027] In this embodiment, the asymmetric triangular hinge 32 includes two supporting parts 324, one end of the two supporting parts 324 is respectively connected to the two frames of the triangular frame vertically, and the other end of the two supporting parts 324 is connected to the torsion center 323. In other embodiments, the asymmetric triangular hinge includes three supporting parts, one end of the three supporting parts is respectively connected to the three frames of the triangular frame vertically, and the other end of the three supporting parts is connected to the torsion center.

[0028] In this embodiment, the above-mentioned triangular frame 322 includes a first frame, a second frame and a third frame which are connected in sequence end to end, the above-mentioned driving foot 321 is arranged at the intersection of the above-mentioned first frame and the above-mentioned second frame, the above-mentioned first frame and the above-mentioned second frame are connected to the above-mentioned third frame through a flexible hinge part, and the above-mentioned support part 324 is connected to the above-mentioned torsion center part 323 through a flexible hinge part.

[0029] By providing the above-mentioned flexible hinge part, different frames of the triangular frame 322 can achieve a certain degree of twisting after overcoming a certain elastic force, and the support part 324 and the twisting center part 323 can achieve a certain degree of twisting after overcoming a certain elastic force, which is conducive to the twisting and resetting of the asymmetric triangular hinge 32. Specifically, the above-mentioned asymmetric triangular hinge 32 is an integrated structure, and the above-mentioned flexible hinge part is actually a thinning part, and arc-shaped grooves are provided on the first frame and the second frame.

[0030] In this embodiment, the torsion hinge 36 is a rigid connector or an elastic connector.

[0031] When the torsion hinge 36 is a rigid connector, the asymmetric triangular hinge 32 overcomes its own elastic force to twist. When the torsion hinge 36 is an elastic connector, the asymmetric triangular hinge 32 overcomes its own elastic force or the torsion hinge 36 to twist.

[0032] In this embodiment, the torsion hinge 36 is a stud.

[0033] The bracket assembly 1 and the asymmetric triangular hinge 32 are connected by studs, which is easy to connect and separate.

[0034] In the present embodiment, the connecting seat 31 is in a concave shape, including a groove bottom 311, two groove wall portions 312 and a groove enclosed by the groove bottom 311 and the groove wall portions 312. The two groove wall portions 312 are arranged on the positive direction side of the Z-axis of the groove bottom 311 and are arranged at a distance along the Y-axis direction. The force hinge 37 connects the groove positions of the two groove wall portions 312, and the piezoelectric stack 33 is arranged in the groove.

[0035] The piezoelectric stack 33 is disposed between the groove bottom 311 , the two groove walls 312 and the force-bearing hinge 37 , and the groove wall 312 can guide the piezoelectric stack 33 to move.

[0036] In this embodiment, the above-mentioned force-bearing hinge 37 includes a first force-bearing portion 371 and a second force-bearing portion 372. The above-mentioned first force-bearing portion 371 is connected to the above-mentioned asymmetric triangular hinge 32 through a flexible hinge portion, the above-mentioned first force-bearing portion 371 is connected to the above-mentioned groove wall portion 312 through a flexible hinge portion, and the above-mentioned second force-bearing portion 372 is connected to the above-mentioned first force-bearing portion 371 through a flexible hinge portion. The above-mentioned second force-bearing portion 372 moves under the guidance of the above-mentioned two groove wall portions 312, and the above-mentioned second force-bearing portion 372 bears the thrust of the above-mentioned piezoelectric stack 33.

[0037] The above-mentioned force-bearing hinge 37 is in the shape of a Chinese character 'tu', with its upper end connected to the asymmetric triangular hinge 32, its bottom in contact with the piezoelectric stack 33, its upper two side ends connected to the two groove wall parts 312, and its lower two side ends slidably connected to the two groove wall parts 312. When the force-bearing hinge 37 is stressed, it not only ensures the accuracy of the applied force direction and restricts the structural damage caused by excessive displacement, but also can amplify the displacement of the piezoelectric stack 33, making the application of force more effective and sufficient. Specifically, the above-mentioned connecting seat 31 and the asymmetric triangular hinge 32 are of an integral structure, the above-mentioned flexible hinge part is actually a thinning part, and an arc-shaped groove is provided on the force-bearing hinge 37.

[0038] In this embodiment, the above-mentioned groove wall part 312 is connected to the above-mentioned groove bottom part 311 through a flexible hinge part.

[0039] By setting the flexible hinge part, the groove wall part 312 can be twisted to a certain extent relative to the groove bottom part 311 after overcoming a certain elastic force, which is beneficial to the torsion and reset of the asymmetric triangular hinge 32. Specifically, the above-mentioned connecting seat 31 is of an integral structure, the above-mentioned flexible hinge part is actually a thinning part, and an arc-shaped groove is provided on the groove wall part.

[0040] In this embodiment, a pre-tightening gasket 38 is provided between the above-mentioned piezoelectric stack 33 and the above-mentioned groove bottom part 311, and a pre-tightening bolt 39 is connected to the above-mentioned groove bottom part 311.

[0041] The pre-tightening gasket 38 and the pre-tightening bolt 39 together constitute a pre-tightening structure. The pre-tightening gasket 38 is in full contact with the piezoelectric stack 33, ensuring the full stress of the piezoelectric stack 33, improving the effectiveness of the pre-tightening structure, and the pre-tightening bolt 39 makes the pre-tightening force adjustable, ensuring the full contact between the piezoelectric stack 33 and the force-bearing hinge. This pre-tightening structure is simple and easy to operate.

[0042] In this embodiment, a friction layer for enhancing its friction is provided on the above-mentioned driving foot 321.

[0043] The driving foot 321 needs to be in contact with the moving part 22, so sufficient friction is required. Specifically, the above-mentioned friction layer is friction ceramics coated on the driving foot 321.

[0044] In this embodiment, the above-mentioned guiding part 21 guides the above-mentioned moving part 22 to translate along the Y-axis direction.

[0045] The piezoelectric stack 33 generates displacement in the Z-axis direction, drives the asymmetric triangular hinge 32 to twist around the center, generates displacement in the Y-axis direction, and then drives the driving foot 321 to generate displacement in the Y-axis direction, and further drives the movable part 22 to displace in the Y-axis direction. The above-mentioned guide member 21 and the above-mentioned movable part 22 constitute a cross roller guide rail system. The movable subassembly adopts a double-row cross roller guide rail system, which is mainly composed of a fixed guide rail, a sliding guide rail, a retaining frame and a guide rail mounting bolt. The guide member 21 is a fixed guide rail, and the movable part 22 is a sliding guide rail. The fixed guide rail is fixed to the support platform of the bracket assembly 1 by the guide rail mounting bolts, and the sliding guide rail is connected to the fixed guide rail by the retaining frame and the cross rollers. The retaining frame and the cross rollers provide support for the guide rail, which reduces the friction between the two guide rails during the sliding process. Mounting bolts are set at both ends of the guide rail for limiting, which limits the displacement distance of the sliding guide rail and avoids the occurrence of derailment.

[0046] Specifically, the bracket assembly 1 includes a shell 11, an upper cover 12 and a fixed connecting piece 13. The upper end of the shell 11 is open, and the bottom of the shell 11 is connected to the guide member 21 by bolts, which is convenient for a stable connection with the movable subassembly to achieve precise positioning of the movable subassembly. The bottom of the shell 11 is connected to the asymmetric triangular hinge 32 by bolts, which is used to fix the asymmetric triangular hinge 32. The bottom of the shell 11 is connected to the connecting seat 31 by bolts, which can effectively lock and fix the shell 11 and the connecting seat 31 to prevent the connecting seat 31 from loosening during operation and causing an increase in errors. The upper cover 12, the side wall of the shell 11 and the fixed connecting piece 13 are connected by bolts to ensure a tight connection between the upper cover 12 and the shell 11.

[0047] Specifically, the shell thickness of the shell 11 is 3 mm, and the shell 11 is preferably made of stainless steel to improve the stability and rigidity of its structure. The shell 11 integrates a variety of functional structures, including a screw hole with a diameter of 3.3 mm for connecting the upper cover 12, a support platform 111 that raises the movable assembly by 2 mm and fully contacts the stator assembly, a screw hole with a diameter of 3.3 mm that firmly connects the guide 21 to the support platform 111, and a 9 mm side length avoidance opening 112 reserved for the movable part 22 on the side wall of the shell 11 to expand the displacement space and facilitate the movement of the movable part 22. The shell 11 is provided with a screw hole for fixing the connecting seat 31 horizontally, and a support column 113 that raises the stator assembly by 2 mm and fixes the asymmetric triangular hinge of the stator assembly. These structures ensure the accuracy of the entire driver and improve the stability of the system.

[0048] The upper cover 12 is composed of a rectangular structure with a length of 63mm and a width of 3mm, and has a fillet with a diameter of 2mm on each vertical side. There are three screw holes on the side of the upper cover, and the spacing between the screw holes on the same side is 6mm. Through thread tightening, the upper cover 12 and the shell 11 are tightly fitted through the fixed connecting piece 13. The fixed connecting piece 13 is composed of a rectangular structure with a length of 20mm, a width of 15mm, and a thickness of 1mm, with fillets with a diameter of 4mm on both sides of the top. At the same time, three circular holes with a center interval of 8mm and a diameter of 2mm are designed on the top, which are connected and fixed with the screw holes of the upper cover 12 by bolts. A long groove 131 with a diameter of 5mm is also provided on the fixed connecting piece 13, which is locked with the screw holes of the side wall of the shell by screws. The fixed connecting piece 13 realizes a tight fit between the upper cover 12 and the shell 11.

[0049] The piezoelectric stack 33 has a length of 6 mm, a width of 4 mm, and a height of 7 mm, and provides power for the entire piezoelectric stick-slip actuator. The Z-axis motion of the piezoelectric stack 33 is converted into the Y-axis motion of the movable part 22 .

[0050] The connection process of the piezoelectric stick-slip actuator in the present invention is described below: First, the guide member 21 is connected and fixed to the housing 11 , the cross roller 23 is fixed in the slide groove of the guide member 21 , and the movable member 22 is fixed to the guide member 21 .

[0051] Secondly, the groove bottom 311 and the asymmetric triangular hinge 32 are connected to the housing 11, and then the piezoelectric stack 33 is placed closely behind the force-bearing hinge 37, and the pre-tightening gasket 38 is pre-tightened, and then the pre-tightening bolt 39 is tightened, and the pre-tightening force is adjusted to make the driving foot 321 fully contact with the movable part 22; Finally, after the internal connection is completed, the upper cover 12 is connected to the housing 11 through the fixing connecting piece 13. The packaging of the entire structure is achieved.

[0052] The working process of the piezoelectric stick-slip actuator of the present invention is described below: A sawtooth voltage signal with a period of T, an excitation voltage amplitude of V, and a symmetry of D is used as the input voltage waveform. The sawtooth drive wave period T1 ranges from 0.001 to 1s, the excitation voltage amplitude V ranges from 60 to 120V, and the symmetry D is 50 to 99.99%. Driven by the sawtooth voltage signal, the piezoelectric stack produces a displacement in the Z-axis direction, driving the asymmetric triangular hinge 32 to twist around the center, producing a displacement in the Y-axis direction, and comprehensively regulating the friction between the active reducer 22 and the driving foot 321, thereby improving the mechanical output characteristics of the piezoelectric stick-slip actuator.

[0053] like Figure 5 Figure 2 shows the initial state of the piezoelectric stick-slip actuator.

[0054] like Figure 6 As shown, it is the slow deformation driving stage of the stator assembly. In the time interval t0 to t1, the piezoelectric stack 33 gradually extends along the Z direction, pushing the asymmetric triangular hinge 32 to amplify the displacement and convert it into displacement in the Y-axis direction. Due to the asymmetric torsion characteristics of the asymmetric triangular hinge 32, the driving foot 321 will produce a small displacement in the Z-axis direction, increasing the pressure between the driving foot 321 and the movable part 22, thereby increasing the friction between the two, causing the movable part 22 to move slightly along the Y-axis under the action of the static friction force fs.

[0055] like Figure 7 As shown, when the voltage reaches the moment t1, the torsional rebound of the internal hinge of the asymmetric triangular hinge 32 and the intervention of the set preload force are utilized to realize the automatic retraction of the driving foot 321 during the forward movement of the movable part 22, thereby effectively reducing the contact time and friction between the driving foot 321 and the movable part 22 in the subsequent rapid rebound stage, and utilizing the tiny inertia generated by the forward movement of the movable part 22 to offset the retreat movement of the movable part caused by the retreat of the driving foot 321.

[0056] like Figure 8 As shown, during the time period from t1 to t2, the piezoelectric stack 33 contracts rapidly, causing the stator assembly to return to its initial state.

[0057] The actions from t0 to t2 are repeated to achieve precise movement of the movable member 22 .

[0058] The present invention proposes a piezoelectric stick-slip actuator with an asymmetric triangular hinge, which cleverly uses the torsion characteristics of the asymmetric triangle to achieve rapid rebound. The asymmetric triangular hinge used in the present invention is used to support and provide mechanical strength, and the integrated design reduces the complexity of assembly. This structure can not only accurately limit the negative impact of friction during the stick-slip process, but also greatly increase the moving distance of the movable part 22, thereby improving the overall performance. In summary, the present invention may be used in micromechanical devices, robots, aerospace engineering, medical equipment or other systems that require frictionless motion due to its advantages such as simple structure and high precision, showing broad application prospects.

[0059] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A piezoelectric stick-slip actuator, characterized in that: include: Bracket assembly, A movable member assembly comprises a guide member and a movable member, wherein the guide member is connected to the bracket assembly, the movable member is connected to the guide member, and the movable member moves under the guidance of the guide member; A stator assembly, comprising a connecting seat, an asymmetric triangular hinge and a piezoelectric stack, wherein the connecting seat is connected to the support assembly via a connecting piece, the asymmetric triangular hinge is arranged between the movable part and the connecting seat, the center of gravity of the asymmetric triangular hinge is connected to the support assembly via a torsion hinge, one of the corners of the asymmetric triangular hinge faces the movable part and is provided with a driving foot, the driving foot is used for a stick-slip connection with the movable part, one of the side edges of the asymmetric triangular hinge faces the connecting seat and is connected to the connecting seat via a force-bearing hinge, and the piezoelectric stack applies a thrust toward the positive direction of the Z axis to the force-bearing hinge; Wherein, when the piezoelectric stack is extended, the asymmetric triangular hinge can overcome the elastic force to perform positive twisting, and the driving foot is adhered to the movable part and drives the movable part to move; When the piezoelectric stack is shortened, the asymmetric triangular hinge is rapidly reversely twisted and reset under the drive of the elastic force, and the driving foot slides relative to the movable member.

2. The piezoelectric stick-slip actuator according to claim 1, characterized in that: The asymmetric triangular hinge includes a triangular frame, a torsion center portion and a support portion. The torsion center portion is located at the center of gravity of the triangular frame and is connected to the frame of the triangular frame through the support portion. The torsion center portion is connected to the bracket assembly through the torsion hinge.

3. The piezoelectric stick-slip actuator according to claim 2, characterized in that: The triangular frame includes a first frame, a second frame and a third frame which are connected end to end in sequence, the driving foot is arranged at the intersection of the first frame and the second frame, the first frame and the second frame are connected to the third frame via a flexible hinge portion, and the support portion is connected to the torsion center portion via a flexible intersection portion.

4. The piezoelectric stick-slip actuator according to claim 3, characterized in that: The torsion hinge is a rigid connector or an elastic connector.

5. The piezoelectric stick-slip actuator according to claim 1, characterized in that: The connecting seat is in a concave shape, including a groove bottom, two groove wall portions and a groove enclosed by the groove bottom and the groove wall portions. The two groove wall portions are arranged at a distance along the Y-axis direction and are connected to the positive direction side of the Z-axis of the groove wall portion. The force-bearing hinge connects the notch positions of the two groove wall portions, and the piezoelectric stack is arranged in the groove.

6. The piezoelectric stick-slip actuator according to claim 5, characterized in that: The force-bearing hinge includes a first force-bearing part and a second force-bearing part, the first force-bearing part is connected to the asymmetric triangular hinge through a flexible hinge part, the first force-bearing part is connected to the groove wall part through a flexible hinge part, the second force-bearing part is connected to the first force-bearing part through a flexible hinge part, the second force-bearing part moves under the guidance of the two groove wall parts, and the second force-bearing part bears the thrust of the piezoelectric stack.

7. The piezoelectric stick-slip actuator according to claim 5, characterized in that: The groove wall portion is connected to the groove bottom portion via a flexible hinge portion.

8. The piezoelectric stick-slip actuator according to claim 5, characterized in that: A pre-tightening gasket is provided between the piezoelectric stack and the bottom of the groove, and a pre-tightening bolt is connected to the bottom of the groove.

9. The piezoelectric stick-slip actuator according to claim 1, characterized in that: The driving foot is provided with a friction layer which enhances its friction force.

10. The piezoelectric stick-slip actuator according to claim 1, characterized in that: The guide member is a fixed guide rail, and the movable member is a movable guide rail. The fixed guide rail guides the movable guide rail to translate along the Y-axis direction.

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