A vibration lapping device and method based on piezoelectric ceramics

Abstract

A vibration lapping device and method based on piezoelectric ceramics, belonging to the technical field of fine machining of thin-walled micro-structured parts. The upper and lower flexible hinge disks are connected by cylindrical pins. The upper flexible hinge disk is installed on piezoelectric ceramic 1, and a polishing head is installed on the lower flexible hinge disk. The two ends of piezoelectric ceramic 2 are respectively connected to the two flexible hinge disks, and piezoelectric ceramic 2 is arranged along the tangent direction of the flexible hinge disk. In the present invention, the up-and-down vibration and the circumferential rotational vibration are converted into a three-dimensional sine annular trajectory for polishing work, and parts with high requirements for dimensional shape accuracy and surface quality can be processed. The flexible polishing disk of the present invention moves through the flexibility of the material and has the function of automatic rebound, reducing energy loss and reducing the number and complexity of the overall mechanism. The present invention uses piezoelectric ceramics as the driving source, and the vibration frequency and amplitude can be changed by changing the voltage of the excitation power supply, so as to adapt to the polishing of different surfaces.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision machining of thin-walled micro-structural parts, and particularly relates to a vibration lapping device and method based on piezoelectric ceramics. Background Art

[0002] Inertial devices are devices that use the structural deformation generated by inertial forces to measure parameters such as the velocity and acceleration of an object's motion relative to inertial space, and play a crucial role in the guidance and control systems of aerospace vehicles such as launch vehicles and missiles. Compared with other precision mechanical instruments, inertial devices have more stringent dimensional requirements and greater machining difficulties. This machining difficulty is mainly reflected in the requirements for the shape and position accuracy, dimensional accuracy, small surface roughness, and strict requirements for the thickness of the machining affected layer of their parts at the micron, sub-micron, or arc-second levels. Moreover, due to the limitation of the compact structure of inertial instruments, the characteristic dimensions of many key inertial instrument parts are only a few microns, and there are a large number of thin-walled parts. These structural characteristics pose great difficulties to the precision machining of inertial instrument parts. And as a typical precision inertial part, the lapping process of the thin-neck structure in the flexible joint part is a key technology in the manufacturing process of flexible joint parts. Currently, the lapping and polishing of flexible joints mainly rely on manual polishing, and there is a lack of special dimensional inspection tools, and the polishing removal amount cannot be accurately quantitatively controlled. Therefore, there is an urgent need for a device suitable for lapping and polishing thin necks at a micro scale. Summary of the Invention

[0003] The purpose of the present invention is to provide a vibration lapping device and method based on piezoelectric ceramics to achieve ultra-smooth polishing at thin necks of micro scales.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A vibration lapping device based on piezoelectric ceramics includes a first piezoelectric ceramic, a cylindrical pin, a second piezoelectric ceramic, a flexible hinge disk, a polishing head, and an excitation power supply; the upper end of the first piezoelectric ceramic is fixed on the machine tool spindle through a connecting member, the two flexible hinge disks up and down are connected by a cylindrical pin, the upper flexible hinge disk is installed on the first piezoelectric ceramic, the polishing head is installed on the lower flexible hinge disk, the two ends of the second piezoelectric ceramic are respectively connected to the two flexible hinge disks, and the second piezoelectric ceramic is arranged along the tangent direction of the flexible hinge disk, and the excitation power supply is connected to the first piezoelectric ceramic and the second piezoelectric ceramic.

[0006] The present invention has the following beneficial effects compared with the prior art:

[0007] 1. The present invention converts the up-and-down vibration and circumferential rotational vibration into a three-dimensional sine annular trajectory for polishing work, and can process parts with high requirements for dimensional shape accuracy and surface quality.

[0008] 2. The structure of the present invention is simple, easy to assemble and produce, and has a low cost.

[0009] 3. The present invention has a small polishing force, high machining accuracy, and can machine thin-walled structural parts.

[0010] 4. The flexible polishing disc of the present invention moves through the flexibility of the material, has an automatic rebound effect, reduces energy loss, and reduces the number and complexity of the overall mechanism.

[0011] 5. The present invention uses piezoelectric ceramics as the driving source, and can change the vibration frequency and amplitude by changing the voltage of the excitation power supply, so as to adapt to polishing of different surfaces.

[0012] 6. The present invention converts the linear motion of the stop block into the vibration period rotation of the flexible hinge disc, and converts simple motion into complex motion.

[0013] 7. The present invention uses support columns as the support structure, reduces material usage, and makes the structure of the present invention simpler.

[0014] 8. The polishing head of the present invention is eccentrically installed to ensure the maximum displacement of the polishing head, so as to achieve the maximum energy utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention;

[0016] Figure 2 is a schematic structural diagram of the flexible hinge disc of the present invention;

[0017] Figure 3 is a simplified simulation diagram of the flexible hinge disc of the present invention;

[0018] Figure 4 is a specific structural diagram of the flexible hinge disc of the present invention;

[0019] Figure 5 is a schematic installation diagram of the pressure sensor of the present invention;

[0020] Figure 6 is a schematic diagram of the tool tip trajectory;

[0021] Among them: 1. Fixed plate; 2. Support column; 3. Piezoelectric ceramic 1; 4. Cylindrical pin; 5. Piezoelectric ceramic 2; 6. Flexible hinge disc; 7. Polishing head; 8. Front cover plate; 9. Excitation power supply; 10. Pressure sensor; 11. Stop block. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In order to better understand the purpose, structure and function of the present invention, the following will further describe the present invention in detail with reference to the drawings.

[0023] AsFigures 1 to 6 As shown in the figure, the present invention provides a vibration lapping device based on piezoelectric ceramics, which includes a first piezoelectric ceramic 3, a cylindrical pin 4, a second piezoelectric ceramic 5, a flexible hinge disc 6, a polishing head 7 and an excitation power supply 9. The upper end of the first piezoelectric ceramic 3 is fixed on the machine tool spindle through a connecting member. The two flexible hinge discs 6 up and down are connected by the cylindrical pin 4. The upper flexible hinge disc 6 is installed on the first piezoelectric ceramic 3, and the polishing head 7 is installed on the lower flexible hinge disc 6. The two ends of the second piezoelectric ceramic 5 are respectively connected to the two flexible hinge discs 6, and the second piezoelectric ceramic 5 is arranged along the tangent direction of the flexible hinge disc 6. The excitation power supply 9 is connected to the first piezoelectric ceramic 3 and the second piezoelectric ceramic 5.

[0024] As Figure 1 shown in the figure, the connecting member includes a fixing plate 1, a front cover plate 8 and a plurality of support columns 2. The excitation power supply 9 is installed on the fixing plate 1. The top end of the fixing plate 1 is fixed on the machine tool spindle. A plurality of support columns 2 are connected between the fixing plate 1 and the front cover plate 8. The lower surface of the front cover plate 8 is connected to the upper surface of the first piezoelectric ceramic 3.

[0025] As Figure 5 shown in the figure, the first piezoelectric ceramic 3 is electrically connected to a pressure sensor 10, and the pressure sensor 10 is installed on the front cover plate 8.

[0026] As Figures 1 to 4 shown in the figure, stoppers 11 are arranged on the inner circumferential surfaces of the two flexible hinge discs 6, and the stopper 11 of one of the flexible hinge discs 6 extends into the other flexible hinge disc 6. The two stoppers 11 are used to install the second piezoelectric ceramic 5.

[0027] The first piezoelectric ceramic 3 is tightly connected to the front cover plate 8 and the flexible hinge disc 6 by applying a pre-tightening force.

[0028] The support column 2 is a rigid element, and the flexible hinge disc 6 is an elastic element.

[0029] The cylindrical pin 4 is used to connect the front cover plate 8, the second piezoelectric ceramic 5 and the two flexible hinge discs 6, and is located at the center of the two flexible hinge discs 6.

[0030] The polishing head 7 is eccentrically installed on the corresponding flexible hinge disc 6.

[0031] The working principle is as follows: When the piezoelectric ceramic 1-3 and the piezoelectric ceramic 2-5 are connected to the excitation power supply 9, the piezoelectric ceramic 1-3 generates deformation due to the inverse piezoelectric effect, driving the overall up-and-down movement of the flexible hinge plate 6. While the piezoelectric ceramic 2-5 pushes the stopper 11 to move linearly, the flexible hinge plate 6 converts it into a rotational movement. When the flexible hinge plate 6 rotates to the maximum angle, it has an automatic rebound function to make the flexible hinge plate 6 return to its original position. At this time, the polishing head 7 makes up-and-down vibrations and periodic rotational movements along with the flexible hinge plate 6, and the tool tip trajectory presents a three-dimensional sine ring-shaped trajectory. While the flexible hinge plate 6 makes up-and-down and rotational movements, the voltages of the piezoelectric ceramic 1-3 and the piezoelectric ceramic 2-5 that control up-and-down and rotation are adjusted respectively, thereby adjusting the vibration frequency and amplitude to adjust the tool tip trajectory to a three-dimensional sine ring-shaped trajectory to achieve the purpose of high-precision polishing.

[0032] The present invention has the characteristics of high polishing efficiency at the neck structure and simple structure for easy assembly.

[0033] It can be understood that the present invention is described through some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. Additionally, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A vibration lapping and polishing device based on piezoelectric ceramics, characterized in that: It includes a piezoelectric ceramic 1 (3), a cylindrical pin (4), a piezoelectric ceramic 2 (5), a flexible hinge disc (6), a polishing head (7) and an excitation power supply (9); the upper end of the piezoelectric ceramic 1 (3) is fixed on the machine tool spindle through a connecting piece, the upper and lower flexible hinge discs (6) are connected through a cylindrical pin (4), the upper flexible hinge disc (6) is installed on the piezoelectric ceramic 1 (3), the polishing head (7) is installed on the lower flexible hinge disc (6), both ends of the piezoelectric ceramic 2 (5) are respectively connected with the two flexible hinge discs (6), and the piezoelectric ceramic 2 (5) is arranged along the tangent direction of the flexible hinge disc (6), the excitation power supply (9) is connected with the piezoelectric ceramic 1 (3) and the piezoelectric ceramic 2 (5), stop blocks (11) are arranged on the inner circumferential surfaces of the two flexible hinge discs (6), and the stop block (11) of one of the flexible hinge discs (6) extends into the other flexible hinge disc (6), and the two stop blocks (11) are used for installing the piezoelectric ceramic 2 (5). The polishing head (7) is eccentrically installed on the corresponding flexible hinge disc (6).

2. The vibration lapping and polishing device based on piezoelectric ceramics according to claim 1, wherein: The connecting piece includes a fixing plate (1), a front cover plate (8) and a plurality of support columns (2); the excitation power supply (9) is installed on the fixing plate (1), the top end of the fixing plate (1) is fixed on the machine tool spindle, a plurality of support columns (2) are connected between the fixing plate (1) and the front cover plate (8), and the lower surface of the front cover plate (8) is connected with the upper surface of the piezoelectric ceramic 1 (3).

3. The vibration lapping and polishing device based on piezoelectric ceramics according to claim 2, characterized in that: The piezoelectric ceramic 1 (3) is electrically connected with a pressure sensor (10), and the pressure sensor (10) is installed on the front cover plate (8).

4. The vibration lapping and polishing device based on piezoelectric ceramics according to claim 2, wherein: The piezoelectric ceramic 1 (3) is tightly connected with the front cover plate (8) and the flexible hinge disc (6) by applying a pre-tightening force.

5. The vibration lapping and polishing device based on piezoelectric ceramics according to claim 2, wherein: The support column (2) is a rigid element, and the flexible hinge disc (6) is an elastic element.

6. The vibration lapping and polishing device based on piezoelectric ceramics according to claim 1, characterized in that: The cylindrical pin (4) is used for connecting the front cover plate (8), the piezoelectric ceramic 2 (5) and the two flexible hinge discs (6), and is located at the center of the two flexible hinge discs (6).

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