Inertial piezoelectric actuator with adjustable stepping precision and controllable service life and actuating method

Abstract

The application discloses a step precision adjustable life controllable inertial piezoelectric actuator and an actuating method, and belongs to the technical field of piezoelectric actuators.The actuator comprises a device base, a circular arc rhombic ring, a joint bearing, an actuating ring, a transmission plate, a pre-tightening rotating plate, a pre-tightening mounting shaft, a disc spring, a pre-tightening rotating top screw and a shell.The application aims to provide a step precision adjustable life controllable inertial piezoelectric actuator which has the advantages of simple structure, high life, high precision and low power consumption.

Description

Technical Field

[0001] This invention relates to the field of actuator technology, specifically to an inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan, and an actuation method thereof. Background Technology

[0002] With the continuous development of science and technology, higher requirements are being placed on actuation platforms in important industrial fields such as national defense, aerospace, and machinery manufacturing. The continuous progress of science and technology has led researchers to focus on developing various actuation devices. Inertial piezoelectric actuators are a type of drive and adjustment device that uses asymmetrical drive signals to generate inertial impact motion. They have extremely wide applications in the aerospace and aviation fields, and are widely used in high-precision adjustment mechanisms due to their simple structure, low resolution, large stroke, and fast response.

[0003] Inertial piezoelectric actuators achieve drive through the periodic frictional coupling of the transmission and actuation device friction pairs. During operation, unavoidable wear occurs on the contact surfaces of the friction pairs, altering the actuator's output characteristics, affecting its normal frictional coupling motion, and impacting its service life. This severely affects the lifespan and repeatability of the inertial piezoelectric actuator. Summary of the Invention

[0004] In order to overcome the technical problems existing in the prior art, the present invention aims to provide an inertial piezoelectric actuator with simple structure, long life, high precision, low power consumption, adjustable step accuracy and controllable life.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan includes a base 1, a rhomboid ring 2, a spherical bearing 3, an actuating ring 4, a transmission plate 5, a preload rotating plate 6, a preload mounting shaft 7, a disc spring 8, a preload rotating set screw 9, and a housing 10. The rhomboid ring 2 is connected to the base 1, and a piezoelectric ceramic 2-2 is embedded within the rhomboid ring 2. A spherical mounting shaft 2-3 is fixedly connected to the upper surface 2-1 of the rhomboid ring, and the spherical mounting shaft 2-3 is coaxial with the rhomboid ring 2. The spherical bearing 3 is fixedly connected to the spherical mounting shaft 2-3, and the actuating ring 4 is fixedly connected to the outer layer of the spherical bearing 3, enabling the actuating ring 4 to... The transmission plate 5 is mounted on the device base 1 and the outer casing 10 via guide rails, and is in contact with the actuating ring 4. The movement of the transmission plate 5 within the guide rails is achieved through frictional coupling with the actuating ring 4. Above the actuating ring 4, a preload rotating plate 6, a preload mounting shaft 7, and a disc spring 8 are mounted. The preload rotating plate 6 is mounted on the preload mounting shaft 7 via pins, achieving rotation in the radial direction. The centers of mass of the preload rotating plate 6 and the preload mounting shaft 7 are located on the same axis as the center of mass of the rhomboid ring 2. One or more preload rotating set screws 9 abut against the disc spring 8 located above the preload rotating plate 6, thereby providing preload force.

[0007] This inertial piezoelectric actuator drives the elongation and shortening of the piezoelectric ceramic 2-2, causing periodic frictional coupling motion between the actuator ring 4 and the transmission plate 5. This enables the transmission plate 5 to achieve bidirectional actuation. During this periodic frictional coupling motion, the contact surface of the friction pair formed by the actuator ring 4 and the transmission plate 5 will wear, affecting the normal frictional coupling motion of the actuator. To address this, the inertial piezoelectric actuator adjusts the wear state between the actuator ring 4 and the transmission plate 5 by rotating the preload rotating screw 9. As the wear of the contact surface increases over time, tightening the preload rotating screw 9 causes the preload rotating plate 6 to rotate, which in turn drives the spherical bearing 3 and the actuator ring 4 to rotate. This changes the contact surface between the actuator ring 4 and the transmission plate 5, restoring the wear state of the contact surface to its original level. This improves the repeatability and lifespan of the actuator, making the accuracy adjustable and the lifespan controllable.

[0008] By monitoring the resistance value between the actuating ring 4 and the transmission plate 5 in real time, and by measuring the resistance value in real time, the wear condition between the contact surfaces of the friction pair can be monitored in real time.

[0009] When the preloaded rotating set screw 9 is adjusted to drive the actuating ring 4 to deflect in the radial direction, the actuating ring 4 drives the transmission plate 5 to move bidirectionally each time through friction. At the same time, due to the existence of the reaction force, the tangential component of the reaction force along the actuating ring 4 will drive the actuating ring 4 to rotate along its axis. Each rotation will change the contact surface of the friction pair formed by the actuating ring 4 and the transmission plate 5, further improving the wear state of the contact surface and improving the repeatability and service life of the actuator.

[0010] The rhombus ring 2 is an arc-shaped rhombus ring, which has a simple structure and is easy to install and assemble. While having a displacement amplification function, it also plays a role in protecting the driving piezoelectric ceramic.

[0011] The method for operating an inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan involves the following steps to induce an upward displacement of the transmission plate 5: First, the driving piezoelectric ceramic 2-2 is slowly energized from zero voltage to its full-stroke voltage, causing it to slowly extend axially. This also drives the actuating ring 4 to move slowly axially. At this time, the upward static friction force provided by the actuating ring 4 overcomes the downward inertial force, keeping the transmission plate 5 and actuating ring 4 relatively stationary, resulting in an upward displacement. Second, the driving piezoelectric ceramic 2-2 is rapidly de-energized from its full-stroke voltage to zero voltage, causing it to rapidly contract axially. This rapidly retracts the actuating ring 4. However, due to the large inertia of the transmission plate 5, the downward displacement of the transmission plate 5 is less than the downward displacement of the actuating ring 4. The difference between the displacements in the first and second steps is one upward step. The first and second steps are then repeated. The transmission plate 5 generates a continuous upward displacement. To generate a downward displacement, firstly, the driving piezoelectric ceramic 2-2 is rapidly energized from zero voltage to full-stroke voltage, causing it to rapidly extend axially and drive the actuating ring 4 to extend rapidly. At this time, the transmission plate 5 is subjected to an upward sliding friction force from the actuating ring 4, but due to its greater inertia, the upward displacement generated by the transmission plate 5 is less than the upward displacement of the actuating ring 4. Secondly, the driving voltage of the driving piezoelectric ceramic 2-2 is slowly reduced to zero voltage, causing it to slowly contract axially and drive the actuating ring 4 to contract slowly. At this time, the downward static friction force from the actuating ring 4 on the transmission plate 5 overcomes the inertial force, and the transmission plate 5 and the actuating ring 4 remain relatively stationary, generating a downward displacement. The difference between the displacements in the first and second steps is one downward step. By repeating the first and second steps, the transmission plate 5 generates a continuous downward displacement.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The high-precision, long-life inertial piezoelectric actuator of the present invention uses piezoelectric ceramics for driving, which has high driving accuracy and fast response.

[0014] 2. The high-precision, long-life inertial piezoelectric actuator of the present invention has a simple and compact structure, and is easy to process and install.

[0015] 3. The inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan described in this invention can monitor the wear condition between the contact surfaces of the friction pair in real time by monitoring the resistance value between the actuating ring 4 and the transmission plate 5.

[0016] 4. The high-precision, long-life inertial piezoelectric actuator of the present invention can improve the repeatability and lifespan of the actuator by slowly tightening the preload rotating set screw 9, which changes the contact surface of the friction pair and restores the wear state of the contact surface to its original level. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the actuator structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the actuator of the present invention in an explosion.

[0019] Figure 3 This is a schematic diagram of the arc-shaped rhomboid ring of the present invention.

[0020] Figure 4 This is a schematic diagram of the pre-tightening rotating plate of the present invention.

[0021] Figure 5 This is a timing diagram of the upward motion driving voltage of the present invention.

[0022] Figure 6 This is a timing diagram of the downward motion driving voltage of the present invention. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 and Figure 2As shown, this invention discloses an inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan, based on contact resistance for real-time assessment and adjustment of wear status. From bottom to top, it includes a base 1, a rhomboid ring 2, a spherical bearing 3, an actuator ring 4, a transmission plate 5, a preload rotating plate 6, a preload mounting shaft 7, a disc spring 8, a preload rotating set screw 9, and a housing 10. The rhomboid ring 2 is connected to the base 1 by screws. A piezoelectric ceramic 2-2 is embedded within the rhomboid ring 2, and a spherical mounting shaft 2-3 is fixedly connected to the upper surface 2-1 of the rhomboid ring, with the spherical mounting shaft 2-3 and the axis of the rhomboid ring 2 aligned on the same straight line. The spherical bearing 3 is fixedly connected to the spherical mounting shaft 2-3, and the actuator ring 4 is fixedly connected to the outer layer of the spherical bearing 3, allowing the actuator ring 4 to rotate around the axial direction. The transmission plate 5 is mounted on the device base 1 and housing 10 via guide rails, and is in contact with the actuating ring 4. The movement of the transmission plate 5 within the guide rails is achieved through frictional coupling with the actuating ring 4. Above the actuating ring 4 are mounted a preload rotating plate 6, a preload mounting shaft 7, and a disc spring 8. The preload rotating plate 6 is mounted on the preload mounting shaft 7 via pins, allowing for radial rotation. The centers of mass of the preload rotating plate 6 and the preload mounting shaft 7 are on the same axis as the center of mass of the rhomboid ring 2. In this example, two preload rotating set screws 9 abut against the disc spring 8 located above the preload rotating plate 6, thereby providing preload force.

[0025] This inertial piezoelectric actuator drives the elongation and shortening of the piezoelectric ceramic 2-2, generating periodic frictional coupling motion between the actuating ring 4 and the transmission plate 5. This causes the transmission plate 5 to actuate bidirectionally. During this periodic frictional coupling motion, the contact surface of the friction pair formed by the actuating ring 4 and the transmission plate 5 inevitably wears, affecting the normal frictional coupling motion of the actuator. To address this, the wear state between the actuating ring 4 and the transmission plate 5 can be adjusted by rotating the preload screw 9. As the wear on the contact surface increases over time, the preload screw 9 is slowly tightened, causing the preload plate 6 to rotate, which in turn rotates the spherical bearing 3 and the actuating ring 4. This changes the contact surface between the actuating ring 4 and the transmission plate 5, restoring the wear state to its original level. This improves the repeatability and lifespan of the actuator, making the accuracy adjustable and the lifespan controllable. Preferably, the wear condition between the contact surfaces of the friction pair is monitored in real time by monitoring the resistance value between the actuating ring 4 and the transmission plate 5 and measuring the resistance value in real time; thus, the decrease in actuation accuracy caused by wear can be assessed in real time.

[0026] On the other hand, when the adjusting preload rotating set screw 9 drives the actuating ring 4 to deflect radially, each time the actuating ring 4 drives the transmission plate 5 to move bidirectionally through friction, the reaction force component along the tangential direction of the actuating ring 4 will cause the actuating ring 4 to rotate along its axis due to the existence of the reaction force. Each rotation will change the contact surface of the friction pair formed by the actuating ring 4 and the transmission plate 5, further improving the wear state of the contact surface, greatly improving the repeatability and service life of the actuator, and making the accuracy of the inertial actuator adjustable and the service life controllable.

[0027] like Figure 3 As shown, the rhombus ring 2 is an arc-shaped rhombus ring, which has a simple structure and is easy to install and assemble. While having a displacement amplification function, it also plays a role in protecting the driving piezoelectric ceramic.

[0028] like Figure 4 The diagram shows a pre-tightening rotating plate 6, which is mounted on the pre-tightening mounting shaft 7 by means of a pin, and can rotate in the radial direction.

[0029] The specific method for achieving the action is as follows: to cause the transmission plate 5 to move upward, such as... Figure 5 As shown, in the first step, the driving piezoelectric ceramic 2-2 is slowly energized from zero voltage to full-stroke voltage, causing it to slowly extend axially. This also drives the actuating ring 4 to slowly move axially. At this time, the transmission plate 5 receives an upward static friction force from the actuating ring 4, which overcomes the downward inertial force. The transmission plate 5 and the actuating ring 4 remain relatively stationary, resulting in an upward displacement. In the second step, the driving piezoelectric ceramic 2-2 is rapidly energized from full-stroke voltage to zero voltage, causing it to rapidly contract axially. This rapidly retracts the actuating ring 4. However, due to the large inertia of the transmission plate 5, its downward displacement is less than the downward displacement of the actuating ring 4. The difference between the displacements in the first and second steps is one upward step. Repeating the first and second steps results in a continuous upward displacement of the transmission plate 5. Similarly, to make the transmission plate 5 produce a downward displacement, as... Figure 6 As shown, in the first step, the driving piezoelectric ceramic 2-2 is rapidly energized from zero voltage to full-stroke voltage, causing it to extend rapidly along the axial direction, which in turn causes the actuating ring 4 to extend rapidly. At this time, the transmission plate 5 is subjected to an upward sliding friction force from the actuating ring 4, but due to its greater inertia, the upward displacement of the transmission plate 5 is less than the upward displacement of the actuating ring 4. In the second step, the driving voltage of the driving piezoelectric ceramic 2-2 is slowly reduced to zero voltage, causing it to contract slowly along the axial direction, which in turn causes the actuating ring 4 to contract slowly. At this time, the downward static friction force from the actuating ring 4 on the transmission plate 5 can overcome the inertial force, and the transmission plate 5 and the actuating ring 4 remain relatively stationary, producing a downward displacement. The difference between the displacements in the first and second steps is a downward step. By repeating the first and second steps, the transmission plate 5 produces a continuous downward displacement.

Claims

1. An inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan, characterized in that: The device includes a base (1), a rhomboid ring (2), a spherical bearing (3), an actuating ring (4), a transmission plate (5), a preload rotating plate (6), a preload mounting shaft (7), a disc spring (8), a preload rotating set screw (9), and a housing (10). The rhomboid ring (2) is connected to the base (1), and the piezoelectric ceramic (2-2) is embedded in the rhomboid ring (2). A spherical mounting shaft (2-3) is fixedly connected to the upper surface (2-1) of the rhomboid ring, and the spherical mounting shaft (2-3) is coaxial with the rhomboid ring (2). The spherical bearing (3) is fixedly connected to the spherical mounting shaft (2-3), and the actuating ring (4) is fixedly connected to the outer layer of the spherical bearing (3), so that the actuating ring (4) can rotate around the axial direction. Rotation; the transmission plate (5) is mounted on the device base (1) and the outer shell (10) via guide rails, and is in contact with the actuating ring (4). The movement of the transmission plate (5) within the guide rails is achieved through frictional coupling with the actuating ring (4); a preload rotating plate (6), a preload mounting shaft (7) and a disc spring (8) are mounted above the actuating ring (4). The preload rotating plate (6) is mounted on the preload mounting shaft (7) via pins to achieve rotation in the radial direction. The center of mass of the preload rotating plate (6) and the preload mounting shaft (7) is on the same axis as the center of mass of the rhomboid ring (2); one or more preload rotating set screws (9) respectively abut against the disc spring (8) located above the preload rotating plate (6) to provide preload force; The inertial piezoelectric actuator drives the piezoelectric ceramic (2-2) to elongate and shorten, thereby generating periodic frictional coupling motion between the actuator ring (4) and the transmission plate (5), and driving the transmission plate (5) to achieve bidirectional actuation. During this periodic frictional coupling motion, the contact surface of the friction pair formed by the actuator ring (4) and the transmission plate (5) will wear, affecting the normal frictional coupling motion of the actuator. To address this, the inertial piezoelectric actuator adjusts the wear state between the actuator ring (4) and the transmission plate (5) by rotating the preload rotating screw (9). As the wear of the contact surface increases over time, the preload rotating screw (9) is tightened, causing the preload rotating plate (6) to rotate, which in turn drives the spherical bearing (3) and the actuator ring (4) to rotate, thereby changing the contact surface between the actuator ring (4) and the transmission plate (5). At this time, the wear state of the contact surface returns to the original level, thereby improving the repeatability and lifespan of the actuator, making the accuracy of the inertial piezoelectric actuator adjustable and its lifespan controllable. When the preloaded rotating set screw (9) of the inertial piezoelectric actuator drives the actuator ring (4) to deflect in the radial direction, the actuator ring (4) drives the transmission plate (5) to move in both directions through friction each time. At the same time, due to the existence of the reaction force, the reaction force component along the tangential direction of the actuator ring (4) will drive the actuator ring (4) to rotate along its axis. Each rotation will change the contact surface of the friction pair formed by the actuator ring (4) and the transmission plate (5), further improving the wear state of the contact surface and improving the repeatability and service life of the actuator.

2. The inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan according to claim 1, characterized in that: By real-time monitoring of the resistance value between the actuating ring (4) and the transmission plate (5), the wear condition between the contact surfaces of the friction pair can be monitored in real time by measuring the resistance value in real time.

3. The inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan according to claim 1, characterized in that: The rhombus ring (2) is an arc-shaped rhombus ring.

4. The actuation method of an inertial piezoelectric actuator with adjustable stepping accuracy and controllable lifespan according to any one of claims 1 to 3, characterized in that: To make the transmission plate (5) move upward, firstly, the driving piezoelectric ceramic (2-2) is slowly energized from zero voltage to full stroke voltage, causing the driving piezoelectric ceramic (2-2) to slowly extend along the axial direction, similarly driving the actuating ring (4) to move slowly along the axial direction. At this time, the transmission plate (5) is provided with an upward static friction force by the actuating ring (4), which can overcome the downward inertial force. The transmission plate (5) and the actuating ring (4) remain relatively stationary, generating an upward displacement. Secondly, the driving piezoelectric ceramic (2-2) is rapidly reduced from full stroke voltage to zero voltage, causing the driving piezoelectric ceramic (2-2) to rapidly contract along the axial direction, driving the actuating ring (4) to quickly retract. However, due to the large inertia of the transmission plate (5), the downward displacement of the transmission plate (5) is less than the downward displacement of the actuating ring (4). The difference between the displacements in the first and second steps is one upward step. Repeating the first and second steps, the transmission plate (5) generates a continuous upward displacement. The transmission plate (5) generates a downward displacement. In the first step, the driving piezoelectric ceramic (2-2) is rapidly energized from zero voltage to full stroke voltage, and the driving piezoelectric ceramic (2-2) extends rapidly along the axial direction, causing the actuating ring (4) to extend rapidly. At this time, the transmission plate (5) is subjected to an upward sliding friction force from the actuating ring (4). However, due to its large inertia, the upward displacement generated by the transmission plate (5) is less than the upward displacement of the actuating ring (4). In the second step, the driving voltage of the driving piezoelectric ceramic (2-2) is slowly reduced to zero voltage, and the driving piezoelectric ceramic (2-2) contracts slowly along the axial direction, causing the actuating ring (4) to contract slowly. At this time, the downward static friction force from the actuating ring (4) on the transmission plate (5) overcomes the inertial force, and the transmission plate (5) and the actuating ring (4) remain relatively stationary, generating a downward displacement. The difference between the displacements in the first and second steps is a downward step. Repeating the first and second steps, the transmission plate (5) generates a continuous downward displacement.

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