A piezoelectric actuator

Abstract

The application discloses a piezoelectric driver, comprising a driving assembly, a moving assembly and a pre-tightening assembly, the pre-tightening assembly is used for applying a pre-tightening force to the driving assembly, the driving assembly comprises two groups of piezoelectric driving units located above and below the moving assembly, each piezoelectric driving unit comprises two longitudinal telescopic piezoelectric stacks, a parallelogram hinge and a bridge hinge, one side of the parallelogram hinge is in contact with the moving assembly, and the side opposite to the side is connected with the bridge hinge; one of the two longitudinal telescopic piezoelectric stacks is connected with the bridge hinge to control longitudinal telescopic movement of the bridge hinge; the other longitudinal telescopic piezoelectric stack is connected with the parallelogram hinge to control transverse telescopic movement of the parallelogram hinge. The bridge hinge can provide a longitudinal pre-tightening force, the parallelogram hinge can realize high-precision and small-step movement of the moving assembly in two directions of positive and negative directions, and the piezoelectric stack does not need to be sheared, so that the cost of the driving assembly can be effectively reduced.

Description

Technical Field

[0001] This application relates to the field of micro-displacement drive technology, and in particular to a piezoelectric actuator. Background Technology

[0002] Piezoelectric actuators are actuators designed to output precision motion by utilizing the inverse piezoelectric effect of piezoelectric materials. Piezoelectric actuators have the advantages of simple structure, low speed and high torque, and are widely used in many precision motion fields.

[0003] Existing piezoelectric actuators can only bond telescopic piezoelectric stacks and shear piezoelectric stacks together to achieve lateral and longitudinal displacement. The piezoelectric stack assembly composed of telescopic piezoelectric stacks and shear piezoelectric stacks is expensive and inconvenient to maintain. Summary of the Invention

[0004] The purpose of this application is to provide a piezoelectric actuator that enables a moving component to move in both forward and reverse directions, and uses only longitudinal telescopic piezoelectric stacks instead of shear piezoelectric stacks, thereby reducing the difficulty of manufacturing piezoelectric ceramics.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A piezoelectric actuator includes: a drive assembly, a motion assembly, and a preload assembly. The preload assembly applies a preload force to the drive assembly. The drive assembly includes two sets of piezoelectric drive units located above and below the motion assembly. Each piezoelectric drive unit includes two longitudinally telescopic piezoelectric stacks, a parallelogram hinge, and a bridge hinge. One side of the parallelogram hinge contacts the motion assembly, and the side opposite to that side is connected to the bridge hinge.

[0007] One of the longitudinally telescopic piezoelectric stacks is connected to the bridge hinge to control the longitudinal telescopic movement of the bridge hinge, the longitudinal telescopic direction of the bridge hinge being perpendicular to the moving direction of the moving component; the other longitudinally telescopic piezoelectric stack is connected to the parallelogram hinge to control the lateral telescopic movement of the parallelogram hinge, the lateral telescopic direction of the parallelogram hinge being parallel to the moving direction of the moving component.

[0008] Preferably, the piezoelectric actuator includes two drive components distributed along the moving direction of the moving component. During the stepping motion, one set of drive components clamps the moving component, while the other set of drive components drives the moving component.

[0009] Preferably, the pre-tightening assembly includes a wedge and a pre-tightening screw, the pre-tightening screw being used to control the movement of the wedge to adjust the pre-tightening force of the longitudinally telescopic piezoelectric stack.

[0010] Preferably, the side of the parallelogram hinge that is in line contact with the motion component has an arc-shaped protrusion, and the arc-shaped protrusion is in line contact with the surface of the motion component.

[0011] Preferably, the side of the parallelogram hinge that is in line contact with the motion component has multiple arc-shaped protrusions, which are arranged parallel to each other and perpendicular to the motion direction of the motion component.

[0012] Preferably, it also includes a housing for accommodating the motion component.

[0013] Compared with existing technologies, the above technical solution has the following advantages:

[0014] This application provides a piezoelectric actuator, comprising: a drive assembly, a motion assembly, and a preload assembly. The preload assembly applies a preload force to the drive assembly. The drive assembly includes two sets of piezoelectric drive units located above and below the motion assembly. Each piezoelectric drive unit includes two longitudinally telescopic piezoelectric stacks, a parallelogram hinge, and a bridge hinge. One side of the parallelogram hinge contacts the motion assembly, and the opposite side is connected to the bridge hinge. One longitudinally telescopic piezoelectric stack is connected to the bridge hinge to control the longitudinal telescopic movement of the bridge hinge, the longitudinal telescopic direction of which is perpendicular to the movement direction of the motion assembly. The other longitudinally telescopic piezoelectric stack is connected to the parallelogram hinge to control the lateral telescopic movement of the parallelogram hinge, the lateral telescopic direction of which is parallel to the movement direction of the motion assembly. The bridge hinge can telescopically provide a longitudinal preload force, and the parallelogram hinge can telescopically, enabling high-precision, small-step movement of the motion assembly in both directions. Furthermore, it eliminates the need for shearing the piezoelectric stacks, effectively reducing the cost of the drive assembly. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a piezoelectric actuator;

[0017] Figure 2 Top view of the piezoelectric actuator;

[0018] Figure 3 for Figure 2 Sectional view along line AA;

[0019] Figure 4 A schematic diagram of a bridge hinge and a parallelogram hinge from one view direction;

[0020] Figure 5 A schematic diagram of another view of the bridge hinge and the parallelogram hinge;

[0021] Figure 6 An exploded view of a piezoelectric actuator at one step. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Please refer to Figures 1-6 , Figure 1 This is a schematic diagram of the structure of a piezoelectric actuator; Figure 2 Top view of the piezoelectric actuator; Figure 3 for Figure 2 Sectional view along line AA; Figure 4 A schematic diagram of a bridge hinge and a parallelogram hinge from one view direction; Figure 5 A schematic diagram of another view of the bridge hinge and the parallelogram hinge; Figure 6 An exploded view of a piezoelectric actuator at one step.

[0024] This application provides a piezoelectric actuator, comprising: a drive assembly, a motion assembly, a preload assembly, and a support assembly. The support assembly includes a housing 8 for accommodating the drive assembly. The motion assembly includes a motion shaft 6. The preload assembly applies a preload force to the drive assembly. The drive assembly includes two sets of piezoelectric drive units located above and below the motion assembly. Each piezoelectric drive unit includes two longitudinally telescopic piezoelectric stacks 1, a parallelogram hinge 2, and a bridge hinge 3. One side of the parallelogram hinge 2 contacts the motion assembly, and the opposite side is connected to the bridge hinge 3. One of the longitudinally telescopic piezoelectric stacks 1 is connected to the motion assembly. A bridge hinge 3 is connected to control the longitudinal extension and retraction of the bridge hinge 3. The longitudinal extension and retraction direction of the bridge hinge 3 is perpendicular to the movement direction of the moving component. The longitudinal extension and retraction piezoelectric stack 1 is its input end, and the rigid connection point with the parallelogram hinge 2 is its output end. The input end generates lateral extension and retraction motion, and the output end generates longitudinal preload motion. The longitudinal extension and retraction piezoelectric stack 1 is located in the middle of the bridge hinge 3, and the two sides of the bridge hinge 3 are flexible hinges. Another longitudinal extension and retraction piezoelectric stack 1 is connected to the parallelogram hinge 2 to control the lateral extension and retraction of the parallelogram hinge 2. The lateral extension and retraction direction of the parallelogram hinge 2 is parallel to the movement direction of the moving component. The bridge hinge 3 can extend and retract longitudinally to provide longitudinal preload, and the parallelogram hinge 2 can extend and retract laterally to achieve high-precision, small-step movement of the moving component in both directions. Furthermore, it eliminates the need for shearing the piezoelectric stack, effectively reducing the cost of the drive component.

[0025] Furthermore, the piezoelectric actuator includes two drive components distributed along the moving direction of the moving component. During stepping motion, one set of drive components clamps the moving component, while the other set of drive components drives the moving component, thereby improving the stability of the moving component during stepping motion.

[0026] In some embodiments, such as Figure 3 As shown, the pre-tightening assembly includes a wedge 5 and a pre-tightening screw 4. The wedge 5 is located between the longitudinal telescopic piezoelectric stack 1 and the corresponding hinge. By turning the pre-tightening screw 4, the movement of the wedge 5 can be controlled to control the telescopic amount of the longitudinal telescopic piezoelectric stack 1, thereby achieving the purpose of adjusting the pre-tightening force of the longitudinal telescopic piezoelectric stack 1 to ensure the high-precision and high-driving-force output of the piezoelectric actuator.

[0027] Furthermore, an arc-shaped protrusion 7 is provided on the side of the parallelogram hinge 2 that makes line contact with the moving component, and the arc-shaped protrusion 7 makes line contact with the surface of the moving component. Preferably, multiple arc-shaped protrusions 7 are provided on the side of the parallelogram hinge 2 that makes line contact with the moving component. The multiple arc-shaped protrusions 7 are arranged parallel to each other and perpendicular to the movement direction of the moving component. The arc-shaped protrusion 7 is preferably a semi-cylindrical structure. By contacting the moving component with the arc-shaped protrusion 7, wear between the two can be reduced, thereby improving service life.

[0028] Please refer to Figure 6 The following explanation uses one step of a piezoelectric actuator as an example, including the following steps:

[0029] a: The bridge hinge 3 of the left drive assembly extends to provide longitudinal preload, the parallelogram hinge 2 of the right drive assembly swings to the right, and the bridge hinge 3 of the right drive assembly shortens.

[0030] b: The bridge hinge 3 of the right drive assembly is extended to provide longitudinal preload, otherwise it remains unchanged;

[0031] c: The bridge hinge 3 of the left drive assembly shortens, the parallelogram hinge 2 of the left drive assembly swings to the right, the bridge hinge 3 of the right drive assembly extends to provide longitudinal preload, and the parallelogram hinge 2 of the right drive assembly swings to the left.

[0032] d: The bridge hinge 3 of the left drive assembly extends to provide longitudinal preload, and the bridge hinge 3 of the right drive assembly extends to provide longitudinal preload, while the rest remain unchanged;

[0033] e: The bridge hinge 3 of the left drive assembly extends to provide longitudinal preload, the parallelogram hinge 2 of the left drive assembly swings to the left, the bridge hinge 3 of the right drive assembly shortens, and the parallelogram hinge 2 of the right drive assembly swings to the right.

[0034] After completing the above abcdea process, the piezoelectric actuator moves the motion axis 6 laterally by a distance of △Y.

[0035] By repeatedly performing the above abcdea process, the piezoelectric actuator can achieve continuous stepping motion in the lateral direction.

[0036] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0037] The foregoing has provided a detailed description of a piezoelectric actuator provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A piezoelectric actuator, characterized in that, include: The drive assembly, motion assembly, and pretensioning assembly are provided. The pretensioning assembly is used to apply a pretensioning force to the drive assembly. The drive assembly includes two sets of piezoelectric drive units located above and below the motion assembly. Each piezoelectric drive unit includes two longitudinally telescopic piezoelectric stacks, a parallelogram hinge, and a bridge hinge. One side of the parallelogram hinge is in contact with the motion assembly, and the side opposite to that side is connected to the bridge hinge. One of the longitudinally telescopic piezoelectric stacks is connected to the bridge hinge to control the longitudinal telescopic movement of the bridge hinge, the longitudinal telescopic direction of the bridge hinge being perpendicular to the moving direction of the moving component; the other longitudinally telescopic piezoelectric stack is connected to the parallelogram hinge to control the lateral telescopic movement of the parallelogram hinge, the lateral telescopic direction of the parallelogram hinge being parallel to the moving direction of the moving component.

2. The piezoelectric actuator according to claim 1, characterized in that, The piezoelectric actuator includes two drive components distributed along the moving direction of the moving component. During stepping motion, one set of drive components clamps the moving component, while the other set of drive components drives the moving component.

3. The piezoelectric actuator according to claim 1, characterized in that, The preload assembly includes a wedge and a preload screw, the preload screw being used to control the movement of the wedge to adjust the preload force of the longitudinally telescopic piezoelectric stack.

4. The piezoelectric actuator according to claim 1, characterized in that, The parallelogram hinge has an arc-shaped protrusion on the side that is in line contact with the motion component, and the arc-shaped protrusion is in line contact with the surface of the motion component.

5. The piezoelectric actuator according to claim 4, characterized in that, The parallelogram hinge has multiple arc-shaped protrusions on the side that is in line contact with the motion component. These arc-shaped protrusions are arranged parallel to each other and perpendicular to the direction of motion of the motion component.

6. The piezoelectric actuator according to claim 1, characterized in that, It also includes a housing for accommodating the moving components.

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