A bridge-type piezoelectric driven linear actuator and control method

Abstract

The present invention belongs to the technical field of piezoelectric actuators, and specifically relates to a bridge-type piezoelectric driven linear actuator and a control method. The bridge-type piezoelectric driven linear actuator includes an upper cover, an outer shell, a flexible hinge micro-motion mechanism, a push rod and a piezoelectric ceramic drive. The outer shell is provided with a flexible hinge micro-motion mechanism, and the flexible hinge micro-motion mechanism is provided with a piezoelectric ceramic driver and a push rod. Grooves are provided on both sides of the outer shell corresponding to the two ends of the push rod, and the two ends of the push rod extend to the outside of the outer shell through the grooves on the outer shell. The flexible hinge micro-motion mechanism is provided with a driving groove, and the push rod is located in the driving groove on the flexible hinge micro-motion mechanism. A ball plate is provided between the push rod and the wall of the driving groove to make them in Hertzian contact. Its beneficial effects are: the structure is simple and compact, and the motion control of two drive heads in two directions is realized by a piezoelectric ceramic driver, the cost is low, and the control method is simple.

Description

Technical Field

[0001] The present invention belongs to the technical field of piezoelectric actuators, and in particular relates to a bridge-type piezoelectric driven linear actuator and a control method thereof. Background Art

[0002] Piezoelectric actuators mainly include: (1) signal-controlled inertial piezoelectric actuators, whose driving principle is to use an asymmetric driving signal as the power source and match it with symmetrical friction forces in the forward and backward directions to achieve driving. However, it requires a complex and precise signal control system, which brings certain difficulties to the miniaturization and integration of the actuator as a whole; (2) friction-controlled inertial piezoelectric precision actuators, whose driving principle is to use the driving force generated by the combined action of a symmetrical driving signal and a mechanical clamping structure as the power source, and achieve driving through asymmetric friction forces in the forward and backward directions. However, the current piezoelectric actuators have complex structures, high costs, and will produce parasitic displacements during movement. Summary of the invention

[0003] In order to overcome the defects of the prior art, the present invention provides a bridge-type piezoelectric driven linear actuator and a control method.

[0004] The present invention is achieved through the following technical solutions: a bridge-type piezoelectric driven linear actuator, comprising an upper cover, an outer shell, a flexible hinge micro-motion mechanism, a push rod and a piezoelectric ceramic drive, wherein a flexible hinge micro-motion mechanism is arranged in the outer shell, a piezoelectric ceramic driver and a push rod are arranged on the flexible hinge micro-motion mechanism, grooves are arranged on both sides of the outer shell corresponding to the two ends of the push rod, and the two ends of the push rod extend to the outside of the outer shell through the grooves on the outer shell, a driving groove is arranged on the flexible hinge micro-motion mechanism, the push rod is located in the driving groove on the flexible hinge micro-motion mechanism, and a ball plate is arranged between the push rod and the groove wall of the driving groove to form Hertzian contact.

[0005] Furthermore, the flexible hinge micro-motion mechanism is hollow in the middle, and semicircular drive heads are symmetrically provided on both sides of the hollow in the middle of the flexible hinge micro-motion mechanism. The push rod is located between the two semicircular drive heads, and the piezoelectric ceramic driver is located in the hollow in the middle of the flexible hinge micro-motion mechanism.

[0006] Furthermore, the piezoelectric ceramic driver is installed in the hollowed-out portion of the flexible hinge micro-motion mechanism through pre-tightening bolts, and the assembly direction is consistent with the long axis direction of the push rod.

[0007] Furthermore, the flexible hinge micro-motion mechanism is provided with ball bearing plates in the driving grooves located on both sides of the semicircular driving head.

[0008] A control method for a bridge-type piezoelectric driven linear actuator is disclosed. The method comprises the following steps: a ball plate is in Hertzian contact with a flexible hinge micro-motion mechanism, and a stick-slip driving mode of a driving head is used to drive a push rod to move in an axial direction. The upper cover is in contact with the driving head through the ball plate, and the driving head can be constrained to prevent parasitic displacement during movement. The preload of the piezoelectric ceramic driver is adjusted by a preload bolt. The stick-slip driving of the piezoelectric ceramic driver is achieved by driving the asymmetric triangular wave voltage. The preload force can be adjusted by adjusting the applied static voltage, and the movement speed and direction can be adjusted by adjusting the applied dynamic voltage.

[0009] The beneficial effects of the present invention are: simple and compact structure, motion control of two drive heads in two directions is achieved through one piezoelectric ceramic driver, low cost and simple control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be further described below in conjunction with the accompanying drawings.

[0011] Attached Figure 1 Schematic diagram of the structure of the present invention; Figure 2 It is a structural schematic diagram of the flexible hinge micro-motion mechanism of the present invention.

[0012] In the figure, 1 is an upper cover, 2 is a housing, 3 is a groove, 4 is a flexible hinge micro-motion mechanism, 5 is a push rod, 6 is a ball plate, 7 is a driving slide, and 8 is a piezoelectric ceramic driver. DETAILED DESCRIPTION

[0013] Attached Figure 1 , 2 This is a specific embodiment of the present invention. The invention is a bridge-type piezoelectric driven linear actuator, comprising an upper cover 1, a housing 2, a flexible hinge micro-motion mechanism 4, a push rod 5 and a piezoelectric ceramic drive, wherein the housing 2 is provided with a flexible hinge micro-motion mechanism 4, and the flexible hinge micro-motion mechanism 4 is provided with a piezoelectric ceramic driver 8 and a push rod 5, grooves 3 are provided on both sides of the housing 2 corresponding to the two ends of the push rod 5, and the two ends of the push rod 5 extend to the outside of the housing 2 through the grooves 3 on the housing 2, and a driving slide 7 is provided on the flexible hinge micro-motion mechanism 4, and the push rod 5 is located in the driving slide 7 on the flexible hinge micro-motion mechanism 4, and a ball plate 6 is provided between the push rod 5 and the groove wall of the driving slide 7 to make them in Hertz contact.

[0014] Furthermore, the middle of the flexible hinge micro-motion mechanism 4 is hollowed out, and semicircular driving heads are symmetrically provided on both sides of the hollowed-out middle part of the flexible hinge micro-motion mechanism 4, the push rod 5 is located between the two semicircular driving heads, and the piezoelectric ceramic driver 8 is located in the hollowed-out middle part of the flexible hinge micro-motion mechanism 4.

[0015] Furthermore, the piezoelectric ceramic driver 8 is installed in the hollowed-out portion of the flexible hinge micro-motion mechanism 4 through pre-tightening bolts, and the assembly direction is consistent with the long axis direction of the push rod 5 .

[0016] Furthermore, the flexible hinge micro-motion mechanism 4 is provided with ball bearing plates 6 in the driving grooves 7 located on both sides of the semicircular driving head.

[0017] A control method for a bridge-type piezoelectric driven linear actuator is disclosed. The ball plate 6 is in Hertzian contact with the flexible hinge micro-motion mechanism 4, and the push rod 5 is driven to move in the axial direction through the stick-slip driving mode of the driving head. The upper cover 1 is in contact with the driving head through the ball plate 6, which can constrain the driving head to prevent it from generating parasitic displacement during movement, and the pre-tightening of the piezoelectric ceramic driver 8 is adjusted by the pre-tightening bolt. The stick-slip driving of the piezoelectric ceramic driver 8 is realized by the voltage drive of an asymmetric triangular wave, the pre-tightening force can be adjusted by adjusting the applied static voltage, and the movement speed and movement direction can be adjusted by adjusting the applied dynamic voltage.

[0018] The present invention is not limited to the above-mentioned embodiments, and anyone should know that any technical solution identical or similar to the present invention made under the inspiration of the present invention shall fall within the protection scope of the present invention.

[0019] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A bridge-type piezoelectric driven linear actuator, comprising an upper cover, a housing, a flexible hinge micro-motion mechanism, a push rod and a piezoelectric ceramic drive, characterized in that: A flexible hinge micro-motion mechanism is provided in the shell, a piezoelectric ceramic driver and a push rod are provided on the flexible hinge micro-motion mechanism, grooves are provided at both ends of the push rod on both sides of the shell respectively, and both ends of the push rod extend outside the shell through the grooves on the shell, a driving slide groove is provided on the flexible hinge micro-motion mechanism, the push rod is located in the driving slide groove on the flexible hinge micro-motion mechanism, and a ball plate is provided between the push rod and the wall of the driving slide groove to form Hertz contact; The ball bearing plate and the flexible hinge micro-motion mechanism are in Hertzian contact, and the push rod is driven to move in the axial direction through the stick-slip driving mode of the driving head; the upper cover and the driving head are in contact through the ball bearing plate, which can constrain the driving head to prevent it from generating parasitic displacement during movement, and the preload bolt is used to adjust the preload of the piezoelectric ceramic driver; the stick-slip drive of the piezoelectric ceramic driver is realized by the voltage drive of an asymmetric triangular wave, the preload force can be adjusted by adjusting the applied static voltage, and the movement speed and direction can be adjusted by adjusting the applied dynamic voltage.

2. The bridge-type piezoelectric driven linear actuator according to claim 1, characterized in that: The flexible hinge micro-motion mechanism is hollowed out in the middle, and semicircular drive heads are symmetrically arranged on both sides of the hollowed-out part in the middle of the flexible hinge micro-motion mechanism. The push rod is located between the two semicircular drive heads, and the piezoelectric ceramic driver is located in the hollowed-out part in the middle of the flexible hinge micro-motion mechanism.

3. The bridge-type piezoelectric driven linear actuator according to claim 1, characterized in that: The piezoelectric ceramic driver is installed in the hollowed-out portion of the flexible hinge micro-motion mechanism through pre-tightening bolts, and the assembly direction is consistent with the long axis direction of the push rod.

4. The bridge-type piezoelectric driven linear actuator according to claim 1, characterized in that: The flexible hinge micro-motion mechanism is provided with ball bearing plates in the driving slide grooves on both sides of the semicircular driving head.

Images