Linear moving platform driven by three-rectangular-plate parallel connection type piezoelectric stator and control method

Abstract

The invention discloses a three-rectangular-plate parallel connection type piezoelectric stator driven linear moving platform and a control method. The three-rectangular-plate parallel connection type piezoelectric stator driven linear moving platform comprises a support assembly, a stator assembly, a moving table assembly and a pre-tightening force adjusting assembly. The stator assembly is fixed on a boss of the base, and the top end of the triangular driving foot is in contact with the friction plate; a moving guide rail and a sliding block in the pre-pressure adjusting mechanism form a moving pair, a spring and a gasket are pressed between a pre-tightening bolt and a bolt bracket, and the tightness of the spring is controlled to realize the adjustment of the pre-tightening force between the triangular driving foot and the friction plate; when the linear moving platform device works, a specified electric signal is applied to the piezoelectric ceramic piece, a first-order longitudinal vibration mode and a second-order bending vibration mode of the stator assembly are excited at the same time, through coupling of the longitudinal vibration mode and the bending vibration mode, the triangular driving foot can generate elliptic motion, and under the action of pretightening force, through friction coupling between the driving foot and the friction plate, the linear moving platform device is driven to move. And the moving plate is pushed to linearly move. The device has the advantages of being compact in structure, easy to install and large in thrust.

Description

Technical Field

[0001] The present invention relates to the field of precision driving technology and piezoelectric motor technology, and in particular to a linear moving platform driven by a piezoelectric stator of three rectangular plates connected in parallel and a control method thereof. Background Art

[0002] With the development of high-precision fields such as biomedicine, IC etching, and motion workbenches, the demand for compact and precision-driven micromotors in actual production activities continues to increase. The performance of traditional electromagnetic motors will continue to decline as the size decreases, and they can no longer meet these requirements. With the continuous development of piezoelectric materials, piezoelectric motors have gained widespread attention as a new type of motor.

[0003] Piezoelectric motor is a kind of motor that uses the inverse piezoelectric effect of piezoelectric ceramics to stimulate the micro-vibration of elastic bodies, and converts the vibration energy into linear movement or rotation of the mover through friction. Compared with traditional electromagnetic motors, piezoelectric motors have the advantages of fast response, direct drive, power-off self-locking, no electromagnetic interference, and the ability to work in a vacuum environment. According to the different motion output methods, piezoelectric motors can be divided into: rotary type and linear type. At present, rotary piezoelectric motors have been industrialized, and the development of linear piezoelectric motors lags slightly behind rotary piezoelectric motors. However, linear motors have compact structures and flexible designs. They can directly output linear motion without conversion mechanisms, which can meet the driving needs of narrow occasions. In 2022, Fan Pingqing proposed a compact miniature longitudinal bending coupled linear piezoelectric motor, whose stator is a pentagonal elastic rod structure, which is symmetrical as a whole, with a hollow design in the middle. The piezoelectric ceramic sheet is attached to the surface of the metal rod perpendicular to the symmetry axis. The piezoelectric ceramic sheet causes the metal rod to undergo local deformation, so that the corner points of the pentagonal elastic structure are linked to vibrate, and then frictionally contact with the mover rod to achieve linear motion of the mover.

[0004] However, this solution also has certain shortcomings. The deformation of a single metal rod is small, and the thrust output by the stator drive foot is small, which limits its application in some large load occasions. The present invention adopts a three-rectangular plate parallel connection structure, which can effectively solve the problem of small output thrust. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problems existing in the prior art and to provide a linear moving platform driven by a piezoelectric stator of three rectangular plates connected in parallel and a control method thereof.

[0006] To achieve the above-mentioned purpose, the technical solution provided by the present invention is: a linear moving platform driven by a piezoelectric stator of three rectangular plates connected in parallel, comprising a support assembly, a stator assembly, a preload adjustment assembly and a moving platform assembly;

[0007] The support assembly includes a base; the stator assembly is composed of three metal rectangular plates and piezoelectric ceramic sheets. The metal rectangular plates overlap in the thickness direction and the three metal rectangular plates adopt a hollow design. A triangular driving foot is arranged on one side of the metal rectangular plate, and three pairs of piezoelectric ceramic sheets are pasted and arranged on the other side of the metal rectangular plate.

[0008] The moving platform assembly consists of a slider, a guide rail, a friction plate screw, a right-angle bracket, a friction plate, a moving plate, and a bracket screw; the slider and the guide rail constitute a moving pair, the right-angle bracket is installed at both ends of the guide rail, the friction plate is installed on the guide rail with a friction plate screw, and the friction plate contacts the top of the triangular driving foot; the moving plate is fixed to the right-angle bracket with a bracket screw;

[0009] The preload force adjustment assembly is composed of a connecting bracket, a preload bolt, a nut, a bolt bracket, a spring, a gasket, a fixing screw, a bracket screw, a preload slider, a moving guide rail, and a connecting screw; the slider is fixed to the left side elevation of the connecting bracket by the connecting screw;

[0010] The bolt bracket is in the shape of a "J". The bolt bracket is fixed to the base by bracket screws, the moving guide rail is fixed to the base by fixing screws, the pre-tightening slider and the moving guide rail constitute a moving pair, the pre-tightening slider is fixedly connected to the connecting bracket, a rectangular hole is provided on the right side of the connecting bracket, the pre-tightening bolt passes through the bolt bracket and the rectangular hole on the right side of the connecting bracket and is fixed by a nut, the top end of the pre-tightening bolt contacts the left end surface of the connecting bracket, and a spring and a gasket are added between the pre-tightening bolt and the bolt bracket, and the pre-tightening force between the friction plate in the stator assembly and the moving platform assembly is adjusted by controlling the tightness of the spring.

[0011] Preferably, a large circular mounting through hole is provided at the center of the metal rectangular plate, and nine small-diameter circular through holes are provided on both sides of the metal rectangular plate.

[0012] Preferably, the support assembly also includes a boss and a support bolt, the base and the boss are integrally formed, the metal rectangular plate is fixed to the boss by the support bolt, and the support bolt passes through the large circular mounting through hole on the metal rectangular plate and is threadedly connected to the threaded hole on the boss.

[0013] Preferably, a square rubber gasket is pressed into the middle of the metal rectangular plate and the boss, and a circular rubber gasket is pressed into between the head of the support bolt and the metal rectangular plate.

[0014] Preferably, the piezoelectric ceramic sheets are adhered to one side of the metal rectangular plate using epoxy conductive adhesive, each pair of piezoelectric ceramic sheets are bilaterally symmetrical about the symmetry axis, and the polarization directions of the piezoelectric ceramic sheets are simultaneously inward or outward along the thickness direction of the piezoelectric ceramic sheets.

[0015] The present invention also discloses a control method for a linear moving platform driven by a piezoelectric stator of three rectangular plates in parallel, wherein the control method is specifically as follows: the piezoelectric ceramic sheets are divided into two groups, I and II, along the left and right symmetric axes, and two groups of piezoelectric ceramic sheets are applied with two-phase electrical signals of equal amplitude, same frequency and time phase difference of π / 2 or -π / 2, wherein group I is Usin(ωt) and group II is Ucos(ωt), wherein U is voltage amplitude, ω is excitation frequency and t is time;

[0016] Secondly, since the electrical signal applied to the piezoelectric ceramic has a phase difference of π / 2, the first-order longitudinal vibration mode and the second-order bending vibration mode of the stator component can be excited simultaneously; when the stator component works in the first-order longitudinal vibration mode, the triangular driving foot produces an up-and-down displacement along the symmetry axis of the stator component, and in the second-order bending vibration mode, the triangular driving foot produces a left-and-right displacement along the direction perpendicular to the symmetry axis of the stator component;

[0017] Finally, through the coupling of longitudinal vibration and bending vibration modes, an elliptical motion at the micron level is formed at the triangular driving foot. Under the action of the preload, the friction coupling between the triangular driving foot and the friction plate drives the mobile platform assembly to move in a straight line. When the phase difference of the excitation signal applied to the two groups of piezoelectric ceramic plates is -π / 2, the elliptical motion trajectory is reversed, and the reverse linear motion of the mobile platform assembly can be achieved.

[0018] Beneficial effects of the present invention:

[0019] 1. The present invention adjusts the preload force between the stator assembly and the moving platform assembly by means of the preload bolts and springs in the preload force adjustment assembly. The operation is convenient and the structure is compact, so that the installation of the entire device is simpler and the manufacturing cost can be reduced.

[0020] 2. The present invention uses three metal rectangular plates that overlap in the thickness direction, and the three metal rectangular plates adopt a hollow design. At the same time, a triangular driving foot structure is superimposed on one side of the metal rectangular plate. The triangular driving foot significantly increases the load of the present invention, and the triangular driving foot can output a greater thrust, which is more suitable for use in large load occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 is a schematic diagram of a support assembly in the present invention;

[0024] Figure 3It is a schematic diagram of the structure of the stator assembly and the position arrangement of the piezoelectric ceramics in the present invention;

[0025] Figure 4 is a schematic diagram of a preload adjustment assembly in the present invention;

[0026] Figure 5 is a schematic diagram of a mobile station assembly in the present invention;

[0027] Figure 6 It is a schematic diagram of the polarization direction and power supply configuration of the piezoelectric ceramic in the present invention;

[0028] Figure 7 It is a schematic diagram of longitudinal vibration mode simulation in the present invention;

[0029] Figure 8 It is a schematic diagram of the bending vibration mode simulation in the present invention.

[0030] Figure annotation:

[0031] 1-support assembly, 11-base, 12-boss, 13-square rubber gasket, 14-support bolt, 15-round rubber gasket;

[0032] 2-stator assembly, 21-metal rectangular plate, 22-triangular driving foot, 23-piezoelectric ceramic sheet;

[0033] 3-preload force adjustment assembly, 31-connecting bracket, 32-preload bolt, 33-nut, 34-bolt bracket, 35-spring, 36-washer, 37-fixing screw, 38-bracket screw, 39-preload slider, 310-moving guide rail, 311-connecting screw;

[0034] 4-mobile platform assembly, 41-slider, 42-guide rail, 43-friction plate screw, 44-right angle bracket, 45-friction plate. 46-mobile plate, 47-bracket screw. DETAILED DESCRIPTION

[0035] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0037] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0038] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0039] Reference Figure 1 , a preferred embodiment of the present invention, a three-rectangular-plate parallel-connected piezoelectric stator-driven linear moving platform, comprising a support assembly 1, a stator assembly 2, a preload adjustment assembly 3 and a moving platform assembly 4;

[0040] Furthermore, if Figure 2 As shown, the support assembly 1 includes a base 11; the support assembly 1 also includes a boss 12 and a support bolt 14, the base 11 and the boss 12 are integrally formed, the metal rectangular plate 21 is fixed to the boss 12 by the support bolt 14, and the support bolt 14 passes through the large circular mounting through hole on the metal rectangular plate 21 and is threadedly connected to the threaded hole on the boss 22.

[0041] Furthermore, a square rubber gasket 13 is pressed into the middle of the metal rectangular plate 21 and the boss 2 to achieve the purpose of vibration reduction, and a circular rubber gasket 15 is pressed into between the head of the support bolt 14 and the metal rectangular plate 21 .

[0042] like Figure 3 As shown, the stator assembly 2 is composed of three metal rectangular plates 21 and piezoelectric ceramic sheets 23. The metal rectangular plates 21 overlap in the thickness direction, and the three metal rectangular plates 21 adopt a hollow design. A triangular driving foot 22 is provided on one side of the metal rectangular plate 21 to amplify the amplitude of the metal rectangular plate 21; three pairs of piezoelectric ceramic sheets 23 are glued and arranged on the other side of the metal rectangular plate 21.

[0043] Furthermore, a large circular mounting hole is provided at the center of the metal rectangular plate 21, and nine small-diameter circular through holes are provided on both sides of the metal rectangular plate 21; the middle large circular mounting through hole runs through the entire stator assembly 2 for clamping and fixing, and the small-diameter circular through holes on the left and right sides are used to reduce the weight of the entire stator assembly 2 while increasing flexibility, and can increase the amplitude of the triangular driving foot 22.

[0044] Furthermore, the piezoelectric ceramic sheets 23 are adhered to one side of the metal rectangular plate 21 using epoxy conductive adhesive. Each pair of piezoelectric ceramic sheets 23 is symmetric about the axis of symmetry, and the polarization direction of the piezoelectric ceramic sheets 23 is either inward or outward along the thickness direction of the piezoelectric ceramic sheets 23.

[0045] As Figure 5 shown, the mobile station assembly 4 consists of a slider 41, a guide rail 42, a friction plate screw 43, a right-angle bracket 44, a friction plate 45, a moving plate 46, and a bracket screw 47. The slider 41 and the guide rail 42 form a moving pair. The right-angle bracket 44 is installed at both ends of the guide rail 42. The friction plate 45 is installed on the guide rail 42 with the friction plate screw 43 to increase the friction force. The friction plate 45 contacts the top of the triangular driving foot 22, and a plane is cut out at the top of the triangular driving foot 22 to increase the contact area between the triangular driving foot 22 and the friction plate 45. The moving plate 46 is fixed to the right-angle bracket 44 with the bracket screw 47 to achieve the installation of the moving plate 46.

[0046] As Figure 4 shown, the pre-tightening force adjustment assembly 3 consists of a connecting bracket 31, a pre-tightening bolt 32, a nut 33, a bolt bracket 34, a spring 35, a gasket 36, a fixing screw 37, a bracket screw 38, a pre-tightening slider 39, a moving guide rail 310, and a connecting screw 311. The slider 41 is fixed to the left vertical surface of the connecting bracket 31 with the connecting screw 311.

[0047] Further, the bolt bracket 34 is in a "J" shape. The bolt bracket 34 is fixed to the base 11 with the bracket screw 38. The moving guide rail 310 is fixed to the base 11 with the fixing screw 37. The pre-tightening slider 39 and the moving guide rail 310 form a moving pair. The pre-tightening slider 39 is fixedly connected to the connecting bracket 31. A rectangular hole is provided on the right side of the connecting bracket 31. The pre-tightening bolt 32 passes through the bolt bracket 34 and is fixed to the rectangular hole on the right side of the connecting bracket 31 through the nut 33. The top of the pre-tightening bolt 32 contacts the left end surface of the connecting bracket 31. A spring 35 and a gasket 36 are added between the pre-tightening bolt 32 and the bolt bracket 34. The pre-tightening force between the stator assembly 2 and the friction plate 45 in the mobile station assembly 4 is adjusted by controlling the tightness of the spring 35.

[0048] The present invention also discloses a control method for a linear moving platform driven by a three-rectangular-plate parallel-connected piezoelectric stator. The specific control method is as follows: The piezoelectric ceramic sheets 23 are divided into two groups, Group I and Group II, along the left-right axis of symmetry. Two-phase electrical signals with equal amplitude, the same frequency, and a time phase difference of π / 2 or -π / 2 are applied to the two groups of piezoelectric ceramic sheets 23. Group I is Usin(ωt), and Group II is Ucos(ωt), where U is the voltage amplitude, ω is the excitation frequency, and t is time.

[0049] Secondly, since the electrical signal applied to the piezoelectric ceramic sheet 23 has a phase difference of π / 2, the first-order longitudinal vibration mode and the second-order bending vibration mode of the stator component 2 can be excited simultaneously; the simulation schematic diagrams of the first-order longitudinal vibration and the second-order bending vibration are shown in FIG. Figure 6 and Figure 7 shown.

[0050] When the stator assembly 2 operates in the first-order longitudinal vibration mode, the triangular driving foot 22 generates an up-and-down displacement along the symmetry axis of the stator assembly 2, and in the second-order bending vibration mode, the triangular driving foot 22 generates a left-and-right displacement along the symmetry axis of the stator assembly 2;

[0051] Finally, through the coupling of longitudinal vibration and bending vibration modes, an elliptical motion of micrometer level is formed at the triangular driving foot 22. Under the action of the preload force, the friction coupling between the triangular driving foot 22 and the friction plate 45 drives the moving platform assembly 4 to move in a straight line. When the phase difference of the excitation signal applied to the two groups of piezoelectric ceramic sheets 23 is -π / 2, the elliptical motion trajectory is reversed, and the reverse linear motion of the moving platform assembly 4 can be realized.

[0052] The present invention adjusts the preload force between the stator assembly 2 and the moving platform assembly 4 by means of the preload bolt 32 and the spring 35 in the preload force adjustment assembly 3, which is convenient to operate and compact in structure, making the installation of the entire device simpler and reducing the manufacturing cost.

[0053] Secondly, the present invention uses three metal rectangular plates 21 to overlap along the thickness direction, and the three metal rectangular plates 21 adopt a hollow design. At the same time, a triangular driving foot structure is superimposed on one side of the metal rectangular plate 21. The triangular driving foot 22 significantly increases the load of the present invention. The triangular driving foot 22 can output a greater thrust, which is more suitable for use in large load occasions.

[0054] Under the premise that no conflict occurs, those skilled in the art may freely combine and superimpose the above-mentioned additional technical features.

[0055] The above description is only a preferred implementation mode of the present invention. Any technical solution that achieves the purpose of the present invention by substantially the same means belongs to the protection scope of the present invention.

Claims

1. A linear motion platform driven by a piezoelectric stator with three rectangular plates connected in parallel, characterized in that: It includes a support assembly, a stator assembly, a preload adjustment assembly and a moving platform assembly; The support assembly includes a base; the stator assembly is composed of three metal rectangular plates and piezoelectric ceramic sheets. The metal rectangular plates overlap in the thickness direction and the three metal rectangular plates adopt a hollow design. A triangular driving foot is arranged on one side of the metal rectangular plate, and three pairs of piezoelectric ceramic sheets are pasted and arranged on the other side of the metal rectangular plate. The moving platform assembly consists of a slider, a guide rail, a friction plate screw, a right-angle bracket, a friction plate, a moving plate, and a bracket screw; the slider and the guide rail constitute a moving pair, the right-angle bracket is installed at both ends of the guide rail, the friction plate is installed on the guide rail with a friction plate screw, and the friction plate contacts the top of the triangular driving foot; the moving plate is fixed to the right-angle bracket with a bracket screw; The preload force adjustment assembly is composed of a connecting bracket, a preload bolt, a nut, a bolt bracket, a spring, a gasket, a fixing screw, a bracket screw, a preload slider, a moving guide rail, and a connecting screw; the slider is fixed to the left side elevation of the connecting bracket by the connecting screw; The bolt bracket is in the shape of a "J". The bolt bracket is fixed to the base by bracket screws, the moving guide rail is fixed to the base by fixing screws, the pre-tightening slider and the moving guide rail constitute a moving pair, the pre-tightening slider is fixedly connected to the connecting bracket, a rectangular hole is provided on the right side of the connecting bracket, the pre-tightening bolt passes through the bolt bracket and is fixed by a nut on the right side of the connecting bracket, the top end of the pre-tightening bolt contacts the left end surface of the connecting bracket, and a spring and a gasket are added between the pre-tightening bolt and the bolt bracket, and the pre-tightening force between the friction plate in the stator assembly and the moving platform assembly is adjusted by controlling the tightness of the spring.

2. The three-rectangular-plate parallel-connected piezoelectric stator driven linear motion platform according to claim 1, characterized in that: A large circular mounting through hole is arranged at the center of the metal rectangular plate, and nine small-diameter circular through holes are arranged on both sides of the metal rectangular plate.

3. The three-rectangular-plate parallel-connected piezoelectric stator driven linear motion platform according to claim 2, characterized in that: The support assembly also includes a boss and a support bolt. The base and the boss are integrally formed. The metal rectangular plate is fixed to the boss by the support bolt. The support bolt passes through the large circular mounting through hole on the metal rectangular plate and is threadedly connected to the threaded hole on the boss.

4. The three-rectangular-plate parallel-connected piezoelectric stator driven linear motion platform according to claim 3, characterized in that: A square rubber gasket is pressed into the middle of the metal rectangular plate and the boss, and a round rubber gasket is pressed into between the head of the support bolt and the metal rectangular plate.

5. The three-rectangular-plate parallel-connected piezoelectric stator driven linear motion platform according to claim 1, characterized in that: The piezoelectric ceramic sheets are adhered to one side of the metal rectangular plate using epoxy conductive adhesive. Each pair of piezoelectric ceramic sheets is bilaterally symmetrical about the symmetry axis, and the polarization directions of the piezoelectric ceramic sheets are simultaneously inward or outward along the thickness direction of the piezoelectric ceramic sheets.

6. A method for controlling a linear moving platform driven by a piezoelectric stator of three rectangular plates connected in parallel according to any one of claims 1 to 5, characterized in that: The control method is specifically as follows: the piezoelectric ceramic sheets are divided into two groups, I and II, along the left and right symmetric axes, and two groups of piezoelectric ceramic sheets are applied with two-phase electrical signals of equal amplitude, same frequency and time phase difference of π / 2 or -π / 2, group I is Usin(ωt), group II is Ucos(ωt), where U is the voltage amplitude, ω is the excitation frequency, and t is the time; Secondly, since the electrical signal applied to the piezoelectric ceramic has a phase difference of π / 2, the first-order longitudinal vibration mode and the second-order bending vibration mode of the stator component can be excited simultaneously; when the stator component works in the first-order longitudinal vibration mode, the triangular driving foot produces an up-and-down displacement along the symmetry axis of the stator component, and in the second-order bending vibration mode, the triangular driving foot produces a left-and-right displacement along the direction perpendicular to the symmetry axis of the stator component; Finally, through the coupling of longitudinal vibration and bending vibration modes, an elliptical motion at the micron level is formed at the triangular driving foot. Under the action of the preload, the friction coupling between the triangular driving foot and the friction plate drives the mobile platform assembly to move in a straight line. When the phase difference of the excitation signal applied to the two groups of piezoelectric ceramic plates is -π / 2, the elliptical motion trajectory is reversed, and the reverse linear motion of the mobile platform assembly can be achieved.

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