Multilayer electrode type electrorheological polishing device and its use and polishing area prediction method

Abstract

The present invention discloses a multi-layer electrode electrorheological polishing device, its use, and a polishing area prediction method. The polishing area prediction method includes: deducing the relationship between the electric field strength and position of the polishing device, calculating the relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field strength, as well as the concentration of the polishing liquid solid phase particles, analyzing the stress conditions of the abrasive particles in the chain structure, and predicting the polishing area that can remove material. The present invention discloses a multi-layer electrode electrorheological polishing device, its use, and a polishing area prediction method. The device has good electric field strength, stronger shear yield resistance, improved flexible polishing head strength, tightly distributed electric field lines, and a large number of abrasive particles in contact with the workpiece surface, thereby improving polishing efficiency and reducing production costs.

Description

Technical Field

[0001] The present invention relates to the technical field of polishing, and in particular to a multi-layer electrode electrorheological polishing device, a use thereof, and a polishing area prediction method. Background Art

[0002] Electrorheological polishing (ERP) is an ultra-precision machining technology, a non-contact polishing method based on the electrorheological effect. The ERP fluid consists of a highly insulating liquid (such as dimethyl silicone oil), dispersed phase particles with excellent dielectric properties (such as starch), and high-hardness abrasive particles (such as diamond). Under the action of a high-voltage electric field, the ERP fluid undergoes an ER effect, rapidly increasing its viscosity and developing shear yield strength. This creates a flexible polishing head, where the dispersed phase particles are arranged in an orderly fashion along the electric field lines. The abrasive particles are trapped between the dispersed phase particles. As the flexible polishing head rotates, the abrasive particles remove material from the workpiece surface.

[0003] In the currently available electrorheological polishing devices, the tool electrodes are mostly double-layer structures consisting of a ring electrode and a central electrode. The electric field strength generated by the double-layer electrode structure is limited, the resulting flexible polishing head is not strong, the polishing effect is poor, the actual effective polishing area is small, and the polishing efficiency is low. In addition, the existing electrorheological polishing tools are mostly fixed-point and linear polishing, which cannot meet the needs of polishing complex components according to specific trajectories. Summary of the Invention

[0004] The present invention overcomes the shortcomings of the existing technology and provides a multi-layer electrode electrorheological polishing device and its use and polishing area prediction method. It has good electric field strength, stronger shear yield resistance, improved flexible polishing head strength, tight electric field line distribution, and a large number of abrasive particles in contact with the workpiece surface, thereby improving polishing efficiency and reducing production costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solutions: an electrorheological polishing device with multi-layer electrodes, comprising: a polishing tool acting in an electrorheological polishing fluid, the polishing tool comprising: a supporting fixed plate, a motor disposed on one side of the supporting fixed plate, a sleeve fixedly mounted on one end on the other side of the supporting fixed plate, a lower end cap disposed on the other end of the sleeve, and a conductive slip ring disposed on the lower end cap;

[0006] The motor is rotatably connected to one end of the tool shaft, and the other end of the tool shaft is connected to the electrode fixing sleeve after passing through the sleeve and the conductive slip ring;

[0007] The electrode fixing sleeve is provided with a needle-shaped electrode and a ring-shaped electrode, and the needle-shaped electrode and the ring-shaped electrode are connected to a power supply through a conductive slip ring.

[0008] In a preferred embodiment of the present invention, the tool shaft is rotatably connected to the sleeve through a bearing group, and the sleeve is coaxially sleeved outside the tool shaft; the bearing group includes an angular contact bearing and a deep groove ball bearing embedded in the sleeve, and the angular contact bearing and deep groove ball bearing are sleeved on the tool shaft at intervals.

[0009] In a preferred embodiment of the present invention, a mounting cavity for inserting the tool shaft is reserved in the sleeve, and a connecting ring is provided in the mounting cavity;

[0010] An installation area 1 for accommodating the coupling is reserved between the connecting ring and the supporting fixing plate, one end of the coupling is connected to the rotating shaft of the motor, and the other end of the coupling is connected to one end of the tool shaft;

[0011] A second installation area for embedding the angular contact bearing and the deep groove ball bearing is reserved between the connecting ring and the lower end cover.

[0012] In a preferred embodiment of the present invention, a first step and a second step are provided on the tool shaft; one side of the angular contact bearing abuts against the second step, one side of the deep groove ball bearing abuts against the first step, and the other side of the deep groove ball bearing abuts against one side of the connecting ring;

[0013] The inner wall and outer wall of the deep groove ball bearing respectively abut against the inner wall of the sleeve and the outer wall of the tool shaft.

[0014] In a preferred embodiment of the present invention, a retaining spring is installed on the tool shaft; a pair of angular contact bearings are installed on the tool shaft; two sides of the angular contact bearings are respectively in contact with the second step and the retaining spring.

[0015] In a preferred embodiment of the present invention, the electrode fixing sleeve is threadedly connected to the tool shaft;

[0016] and / or, the gap between the needle-shaped electrode and the multi-layer ring electrode is 1 mm;

[0017] and / or, the tool shaft is interference fit with the inner ring of the conductive slip ring;

[0018] And / or, the power supply is a high voltage DC power supply;

[0019] And / or, one end of the needle electrode and the ring electrode is connected to the electrode fixing sleeve; the other end of the needle electrode and the ring electrode is immersed in the electrorheological polishing fluid and close to the workpiece in the electrorheological polishing fluid.

[0020] In a preferred embodiment of the present invention, the needle-shaped electrode and the multi-layer ring electrode are connected to each other with one layer between them;

[0021] The outermost layer of the multi-layer ring electrode is connected to the positive electrode of the power supply through a conductive slip ring, and the innermost layer of the needle-shaped electrode is connected to the negative electrode of the power supply through a conductive slip ring;

[0022] The adjacent needle-shaped electrodes and multi-layered ring electrodes have different polarities.

[0023] In a preferred embodiment of the present invention, a method for using an electrorheological polishing device having a multi-layer electrode is implemented using an electrorheological polishing device having a multi-layer electrode. The polishing method comprises the following steps:

[0024] Step S1, selecting a polishing path according to the shape of the workpiece to be polished;

[0025] Step S2, positioning the workpiece to be polished in the processing tank by a fixture, injecting electrorheological polishing fluid into the processing tank so that the electrorheological polishing fluid immerses the workpiece to be polished;

[0026] Step S3, adjusting the Z-direction position of the polishing tool so that the lower end surfaces of the needle-shaped electrode and the multi-layered ring electrode are close to the upper end surface of the workpiece, and the lower end surfaces of the needle-shaped electrode and the multi-layered ring electrode are immersed in the electrorheological polishing fluid;

[0027] Step S4: Turning on the power supply to the needle-shaped electrode and the multi-layered ring electrode generates an electric field between the needle-shaped electrode and the adjacent layers of the multi-layered ring electrode. The electrorheological polishing fluid mixed with dispersed phase particles and abrasive particles at the lower ends of the needle-shaped electrode and the multi-layered ring electrode undergoes an electrorheological effect, turning into a viscous solid, thereby forming a flexible polishing head.

[0028] Step S5, starting the motor of the polishing tool, the motor drives the needle electrode and the multi-layer ring electrode to rotate, and adjusting the speed of the motor to 1000-2500 r / min, while making the polishing tool polish according to the set polishing path;

[0029] Step S6, polishing is completed, the power supply and the motor are turned off, the movement is stopped, and the polished workpiece is taken out.

[0030] In a preferred embodiment of the present invention, a method for predicting a polishing area of ​​an electrorheological polishing device having multi-layer electrodes is implemented using an electrorheological polishing device having multi-layer electrodes. The method for predicting a polishing area comprises the following steps:

[0031] The polishing area where material can be removed is predicted based on the relationship between the electric field strength and position of the polishing device, the relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field strength, the concentration of the solid phase particles in the polishing liquid, and the force conditions of the abrasive particles in the chain structure.

[0032] In a preferred embodiment of the present invention, obtaining the relationship between the electric field intensity and the position of the polishing device includes:

[0033] According to the physical model of the electrode, the electric field intensity at one point is calculated using Coulomb's law, and then the relationship between the electric field intensity and position of the polishing device is obtained using the continuous charge distribution integral method;

[0034] The relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field strength and the concentration of the solid phase particles in the polishing liquid is obtained by:

[0035] Based on the viscosity of the base liquid and the volume fraction of the solid phase particles in the polishing liquid, the initial viscosity before the electric field is applied is calculated; the increased viscosity of the polishing liquid after the electric field is applied is analyzed, and the apparent viscosity of the polishing liquid under the action of the electric field is obtained by adding the initial viscosity and the increased viscosity. The relationship between the apparent viscosity, the electric field intensity, and the volume fraction of the solid phase particles in the polishing liquid is obtained, and the relationship between the viscosity of the polishing liquid that produces the electrorheological effect, the electric field intensity, and the concentration of the solid phase particles in the polishing liquid is obtained;

[0036] The acquisition of the force conditions of abrasive particles in forming a chain structure includes:

[0037] According to the dipole model, in the electrorheological fluid, the dielectric particles are polarized under the action of an external electric field, forming an electric dipole moment. The polarized dielectric particles are arranged into a chain-like structure along the direction of the electric field due to the dipole interaction. The general force conditions of the abrasive particles in the chain-like structure are analyzed to obtain the force conditions of the abrasive particles in the chain-like structure.

[0038] The acquisition of the polishing area that will result in material removal is predicted to include:

[0039] According to the material removal theory, the workpiece surface in the polishing area where material removal occurs must undergo plastic deformation. This requires ensuring that the force on the abrasive particles in the polishing area exceeds the shearing force of the workpiece. The relationship between the force on the abrasive particles and their position is analyzed to determine the maximum area where material removal occurs.

[0040] According to Newton's law of motion, when the tool head rotates, the abrasive particles need to overcome the centrifugal force to produce an effect, and obtain the maximum action area to overcome the centrifugal force;

[0041] The maximum area of ​​action for overcoming centrifugal force is compared with the maximum area of ​​action for producing material removal, and the theoretical polishing area is the intersection of the maximum area of ​​action for overcoming centrifugal force and the maximum area of ​​action for producing material removal.

[0042] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are:

[0043] An electrorheological polishing device and polishing method with multi-layer electrodes uses a multi-layer electrode structure. The multi-layer electrode has good electric field strength and stronger shear yield resistance, which improves the strength of the flexible polishing head. The multi-layer electrode structure makes the electric field lines distributed tightly, and a large number of abrasive particles come into contact with the workpiece surface, thereby improving polishing efficiency and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be further described below with reference to the accompanying drawings and examples.

[0045] Figure 1 A schematic structural diagram of a preferred embodiment of the present invention;

[0046] Figure 2 for Figure 1 A is an enlarged schematic diagram;

[0047] Figure 3 A schematic structural diagram of a polishing tool according to a preferred embodiment of the present invention;

[0048] Figure 4 A cross-sectional view of a polishing tool according to a preferred embodiment of the present invention;

[0049] Figure 5 for Figure 4 A magnified schematic diagram of middle B;

[0050] Figure 6 is a diagram of a flexible polishing head formed at different voltage values ​​in a preferred embodiment of the present invention;

[0051] Figure 7 A simplified schematic diagram of an electrode according to the present invention;

[0052] Figure 8 Schematic diagram of the indentation of abrasive particles on the workpiece;

[0053] Figure 9 Flowchart of the method for predicting polishing area.

[0054] In the figure, 1-polishing tool, 2-power supply, 3-clamp, 4-workpiece, 5-machining groove, 6-electrorheological polishing fluid, 7-support fixing plate, 8-sleeve, 9-lower end cover, 10-tool shaft, 11-conductive slip ring, 12-motor, 13-coupling, 14-circlip, 15-angular contact bearing, 16-deep groove ball bearing, 17-electrode fixing sleeve, 18-needle electrode, 19-ring electrode, 20-first step, 21-second step, 22-screw, 23-first screw, 24-second screw, 25-fifth screw, 26-sixth screw, 27-third screw, 28-fourth screw, 29-flexible polishing head, 30-dispersed phase particles, 31-abrasive particles, 32-connecting ring. DETAILED DESCRIPTION

[0055] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0056] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, bottom, top, etc.), the directional indications are only used to explain the relative positional relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Unless otherwise clearly specified and defined, the terms "set", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a communication between the internal parts of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0057] like Figures 1-6 As shown, an electrorheological polishing device with multi-layer electrodes, wherein the polishing tool 1 includes: a supporting fixed plate 7, a motor 12 is provided on one side of the supporting fixed plate 7, the other side of the supporting fixed plate 7 is fixedly installed with one end of a sleeve 8, the other end of the sleeve 8 is provided with a lower end cover 9, and the lower end cover 9 is provided with a conductive slip ring 11.

[0058] Specifically, a mounting cavity for inserting the tool shaft 10 is reserved within the sleeve 8, and a connecting ring 32 is provided within the mounting cavity. A mounting area for accommodating the coupling 13 is reserved between the connecting ring 32 and the support and fixing plate 7. One end of the coupling 13 is connected to the rotating shaft of the motor 12, and the other end of the coupling 13 is connected to one end of the tool shaft 10. The motor 12 is rotationally connected to one end of the tool shaft 10 through the coupling 13, and the other end of the tool shaft 10 is connected to the electrode fixing sleeve 17 after passing through the sleeve 8 and the conductive slip ring 11. The motor 12 is mounted on the support and fixing plate 7, and the motor 12 shaft is connected to the upper end of the tool shaft 10 through the coupling 13. The coupling 13 used is a flexible coupling, which can effectively absorb vibration and impact, making the entire transmission system stable and reliable.

[0059] Specifically, a second mounting area for a bearing assembly is reserved between the connecting ring 32 and the lower end cap 9. The tool shaft 10 is rotatably connected to the sleeve 8 via the bearing assembly, which is coaxially mounted on the tool shaft 10. The bearing assembly includes an angular contact bearing 15 and a deep groove ball bearing 16, which are embedded in the sleeve 8 and spaced apart from each other on the tool shaft 10.

[0060] Furthermore, the tool shaft 10 is provided with a first step 20 and a second step 21. One side of the angular contact bearing 15 abuts against the second step 21, while one side of the deep groove ball bearing 16 abuts against the first step 20. The other side of the deep groove ball bearing 16 abuts against one side of the connecting ring 32. The inner and outer walls of the deep groove ball bearing 16 abut against the inner wall of the sleeve 8 and the outer wall of the tool shaft 10, respectively. The deep groove ball bearing 16 improves the verticality of the tool shaft 10, with its two ends abutting against the sleeve 8 and the first step 20, respectively. A retaining spring 14 is mounted on the tool shaft 10, along with a pair of angular contact bearings 15. The two sides of the angular contact bearings 15 abut against the second step 21 and the retaining spring 14, respectively. The upper end of the angular contact bearing 15 is positioned by the second step 21, while the lower end is positioned by the retaining spring 14. The angular contact bearings 15 further improve the verticality of the tool shaft 10.

[0061] Specifically, the electrode fixing sleeve 17 is threadedly connected to the tool shaft 10. A needle electrode 18 and a ring electrode 19 are mounted on the electrode fixing sleeve 17, which are connected to the power supply 2 via a conductive slip ring 11. One end of the needle electrode 18 and ring electrode 19 is connected to the electrode fixing sleeve 17; the other ends of the needle electrode 18 and ring electrode 19 are immersed in the electrorheological polishing fluid 6 and positioned close to the workpiece 4 in the electrorheological polishing fluid 6. More specifically, the power supply 2 uses a high-voltage DC power supply. The needle electrode 18 and multiple layers of ring electrodes 19 are interconnected, with each layer separated by a layer. The outermost layer of the multiple layers of ring electrodes 19 is connected to the positive electrode of the power supply 2 via a conductive slip ring 11, while the innermost layer of the needle electrode 18 is connected to the negative electrode of the power supply 2 via a conductive slip ring 11. Adjacent needle electrodes 18 and multiple layers of ring electrodes 19 have different polarities. The gap between adjacent needle electrodes 18 and multiple layers of ring electrodes 19 is 1 mm. Example 2

[0062] like Figures 1-6As shown, an electrorheological polishing device with a multi-layer electrode, wherein the polishing tool 1 includes: a support fixing plate 7, a motor 12 is provided on one side of the support fixing plate 7, and the other side of the support fixing plate 7 is fixedly mounted to one end of a sleeve 8. In this embodiment, the support fixing plate 7 and the sleeve 8 are threadedly connected by a third screw 27 and a fourth screw 28. A lower end cover 9 is provided at the other end of the sleeve 8, and a conductive slip ring 11 is provided on the lower end cover 9. In this embodiment, the lower end cover 9 and the sleeve 8 are threadedly connected by a fifth screw 25 and a sixth screw 26. The outer ring of the conductive slip ring 11 is threadedly connected to the lower end cover 9 by a first screw 23 and a second screw 24.

[0063] Specifically, the sleeve 8 has a mounting cavity for the tool shaft 10, which is equipped with a connecting ring 32. A mounting area for the coupling 13 is reserved between the connecting ring 32 and the support plate 7. One end of the coupling 13 is connected to the rotating shaft of the motor 12, while the other end is connected to one end of the tool shaft 10. The motor 12 is rotatably connected to the one end of the tool shaft 10 via the coupling 13. In this embodiment, the motor 12 is mounted on the support plate 7, and the motor 12 shaft is connected to the upper end of the tool shaft 10 via the coupling 13. The coupling 13 is a flexible coupling that effectively absorbs vibration and shock, ensuring a stable and reliable transmission system. The other end of the tool shaft 10 passes through the sleeve 8 and the conductive slip ring 11 and is connected to the electrode mounting sleeve 17. In this embodiment, the electrode mounting sleeve 17 is detachably connected to the tool shaft 10, allowing for the replacement of multi-layer electrodes of varying sizes, facilitating adaptation to diverse machining requirements and providing a wide range of applications. Specifically, a screw 22 is fixed to the upper end of the electrode fixing sleeve 17 , and the screw 22 is threadedly connected to the tool shaft 10 .

[0064] Specifically, a second mounting area for a bearing assembly is reserved between the connecting ring 32 and the lower end cap 9. The tool shaft 10 is rotatably connected to the sleeve 8 via the bearing assembly, which is coaxially mounted on the tool shaft 10. The bearing assembly includes an angular contact bearing 15 and a deep groove ball bearing 16, which are embedded in the sleeve 8 and spaced apart from each other on the tool shaft 10.

[0065] Furthermore, a first step 20 and a second step 21 are provided on the tool shaft 10; one side of the angular contact bearing 15 abuts against the second step 21, and one side of the deep groove ball bearing 16 abuts against the first step 20. The other side of the deep groove ball bearing 16 abuts against one side of the connecting ring 32. The inner and outer walls of the deep groove ball bearing 16 abut against the inner wall of the sleeve 8 and the outer wall of the tool shaft 10, respectively. In this embodiment, the verticality of the tool shaft 10 is improved by the deep groove ball bearing 16, and the two axial ends of the deep groove ball bearing 16 abut against the sleeve 8 and the first step 20, respectively. A retaining spring 14 is installed on the tool shaft 10; a pair of angular contact bearings 15 are installed on the tool shaft 10; the two sides of the angular contact bearing 15 abut against the second step 21 and the retaining spring 14, respectively. In this embodiment, the upper end of the angular contact bearing 15 is positioned by the second step 21 , and the lower end of the angular contact bearing 15 is positioned by the retaining spring 14 . The angular contact bearing 15 further improves the verticality of the tool shaft 10 .

[0066] Specifically, the electrode mounting sleeve 17 is threadedly connected to the tool shaft 10. A needle electrode 18 and a ring electrode 19 are mounted on the electrode mounting sleeve 17, and these electrodes are connected to the power supply 2 via a conductive slip ring 11. One end of each electrode is connected to the electrode mounting sleeve 17; the other ends of each electrode are immersed in the electrorheological polishing fluid 6 and positioned close to the workpiece 4 within the fluid. More specifically, the power supply 2 utilizes a high-voltage direct current (DC) power supply. The needle electrode 18 and multiple layers of ring electrodes 19 are interconnected with each other, with the positive electrodes of the needle electrodes 18 and multiple layers of ring electrodes 19 connected to each other and to each other. The outermost layer of the multiple layers of ring electrodes 19 is connected to the positive electrode of the power supply 2 via a conductive slip ring 11, while the innermost layer of the needle electrode 18 is connected to the negative electrode of the power supply 2 via a conductive slip ring 11. Adjacent needle electrodes 18 and multiple layers of ring electrodes 19 have different polarities.

[0067] In this embodiment, the gap between the needle electrode 18 and the multi-layered ring electrode 19 is 1 mm. High-voltage insulating adhesive is injected into the inner side of the needle electrode 18 and each layer of the multi-layered ring electrode 19 to prevent sparks between the inner and outer sides of adjacent electrodes. The electrode fixing sleeve 17 is made of Bakelite, which has excellent insulation properties. The tool shaft 10 is made of martensitic stainless steel, while the needle electrode 18 and the multi-layered ring electrode 19 are made of copper. The fixed support plate 7, sleeve 8, and lower end cap 9 are all made of nylon, further enhancing the overall insulation of the device. Example 3

[0068] like Figures 1-6 As shown, based on any one of the embodiments 1 or 2,

[0069] A method for using an electrorheological polishing device having a multi-layer electrode comprises the following steps:

[0070] Step S1 : selecting a polishing path according to the shape of the workpiece 4 to be polished.

[0071] Step S2, positioning the workpiece 4 to be polished in the processing tank 5 by the fixture 3, injecting the electrorheological polishing fluid 6 into the processing tank 5, so that the electrorheological polishing fluid 6 immerses the workpiece 4 to be polished;

[0072] In step S3, the Z-direction position of the polishing tool 1 is adjusted so that the lower end surfaces of the needle electrode 18 and the multi-layered ring electrode 19 are close to the upper end surface of the workpiece 4 and are immersed in the electrorheological polishing fluid 6. Specifically, the distance between the lower end surfaces of the needle electrode 18 and the multi-layered ring electrode 19 and the upper end surface of the workpiece 4 is 0.25-0.75 mm.

[0073] In step S4, power source 2 is turned on to supply power to needle-shaped electrode 18 and multi-layered ring electrode 19. This generates an electric field between adjacent layers of needle-shaped electrode 18 and multi-layered ring electrode 19. Electrorheological effect occurs at the lower ends of needle-shaped electrode 18 and multi-layered ring electrode 19, where electrorheological polishing fluid 6, containing dispersed phase particles 30 and abrasive particles 31, undergoes, transforming the fluid into a viscous, solid-like state, forming a flexible polishing head 29. Specifically, power source 2 supplies power to needle-shaped electrode 18 and multi-layered ring electrode 19 at a voltage in the range of 1000-3000V.

[0074] Step S5, start the motor 12 of the polishing tool 1, the motor 12 drives the needle electrode 18 and the multi-layer ring electrode 19 to rotate, and adjust the speed of the motor 12 to 1000-2500r / min, while making the polishing tool 1 polish according to the set polishing path.

[0075] Step S6, polishing is completed, the power supply 2 and the motor 12 are turned off, the movement is stopped, and the polished workpiece 4 is taken out. Example 4

[0076] like Figures 1-6 As shown, based on any one of the embodiments 1 or 2,

[0077] A polishing method for an electrorheological polishing device having a multi-layer electrode, comprising the following steps:

[0078] Step S1 : selecting a polishing path according to the shape of the workpiece 4 to be polished.

[0079] Step S2, positioning the workpiece 4 to be polished in the processing tank 5 by the fixture 3, injecting the electrorheological polishing fluid 6 into the processing tank 5, so that the electrorheological polishing fluid 6 immerses the workpiece 4 to be polished;

[0080] In step S3, the Z-direction position of the polishing tool 1 is adjusted so that the lower end surfaces of the needle electrode 18 and the multi-layered ring electrode 19 are close to the upper end surface of the workpiece 4 and the lower end surfaces of the needle electrode 18 and the multi-layered ring electrode 19 are immersed in the electrorheological polishing fluid 6. Specifically, the spacing between the lower end surfaces of the needle electrode 18 and the multi-layered ring electrode 19 and the upper end surface of the workpiece 4 is 0.25-0.75 mm. Furthermore, in this embodiment, the position of the polishing tool 1 is adjusted so that a certain gap is maintained between the lower end surfaces of the needle electrode 18 and the multi-layered ring electrode 19 and the workpiece 4, and the lower ends of the needle electrode 18 and the multi-layered ring electrode 19 are immersed in the electrorheological polishing fluid 6. As a preferred embodiment, a fixture 3 is placed in the processing tank 5 to secure the workpiece 4 to be polished. The gap between the needle electrode 18 and the multi-layered ring electrode 19 and the workpiece 4 is 0.25-0.75 mm, generating a high electric field strength, thereby ensuring a good polishing effect. As a preferred solution, the position of the polishing tool 1 is adjusted to keep the gap distance between the lower end surfaces of the needle electrode 18 and the multi-layered ring electrode 19 and the workpiece 4 at 0.5 mm.

[0081] In step S4, power supply 2 is turned on to supply power to the needle-shaped electrode 18 and the multi-layered ring electrode 19. Specifically, the voltage provided by power supply 2 to the needle-shaped electrode 18 and the multi-layered ring electrode 19 is in the range of 1000-3000V. Furthermore, in this embodiment, turning on power supply 2 and adjusting the voltage to 1000-3000V generates a high-voltage electric field between adjacent layers of the needle-shaped electrode 18 and the multi-layered ring electrode 19. The electrorheological polishing fluid 6, which contains dispersed phase particles 30 and abrasive particles 31 at the lower ends of the needle-shaped electrode 18 and the multi-layered ring electrode 19, undergoes an electrorheological effect, transforming it into a viscous solid, thereby forming a flexible polishing head 29. As a preferred embodiment, the voltage is adjusted to 3000V.

[0082] In step S5, the motor 12 of the polishing tool 1 is started. The motor 12 drives the needle electrode 18 and the multi-layered ring electrode 19 to rotate. The speed of the motor 12 is adjusted to 1000-2500 r / min, and the polishing tool 1 is polished according to the set polishing path. Furthermore, in this embodiment, the speed of the polishing tool 1 is adjusted to 1000-2500 r / min, and the polishing tool 1 is moved according to the set polishing path, driving the abrasive particles 31 in the flexible polishing head 29 to remove material from the surface of the workpiece 4, thereby achieving ultra-precision flexible polishing. As a preferred embodiment, the speed of the polishing tool 1 is adjusted to 1500 r / min.

[0083] Step S6, polishing is completed, the power supply 2 and the motor 12 are turned off, the movement is stopped, and the polished workpiece 4 is taken out. Example 5

[0084] like Figures 1-6As shown, based on the fourth embodiment, a polishing area prediction method of an electrorheological polishing device with multi-layer electrodes is adopted in step S5. The polishing area prediction method is implemented by the electrorheological polishing device with multi-layer electrodes, and includes the following steps:

[0085] Based on the relationship between the electric field strength and position of the polishing device, the relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field strength and the concentration of the solid phase particles in the polishing liquid, and the force conditions of the abrasive particles 31 in the chain structure, the polishing area where material can be removed is predicted.

[0086] Specifically, obtaining the relationship between the electric field strength and the position of the polishing device includes:

[0087] According to the physical model of the electrode, the electric field intensity at one point is calculated using Coulomb's law, and then the relationship between the electric field intensity and position of the polishing device is obtained using the continuous charge distribution integral method;

[0088] Specifically, obtaining the relationship between the viscosity of the polishing liquid that produces the electrorheological effect, the electric field strength, and the concentration of the solid phase particles in the polishing liquid includes:

[0089] Based on the viscosity of the base liquid and the volume fraction of the solid phase particles in the polishing liquid, the initial viscosity before the electric field is applied is calculated; the increased viscosity of the polishing liquid after the electric field is applied is analyzed, and the apparent viscosity of the polishing liquid under the action of the electric field is obtained by adding the initial viscosity and the increased viscosity. The relationship between the apparent viscosity, the electric field intensity, and the volume fraction of the solid phase particles in the polishing liquid is obtained, and the relationship between the viscosity of the polishing liquid that produces the electrorheological effect, the electric field intensity, and the concentration of the solid phase particles in the polishing liquid is obtained;

[0090] Specifically, obtaining the force conditions of the abrasive particles 31 in the chain structure includes:

[0091] According to the dipole model, in the electrorheological fluid, dielectric particles are polarized under the action of an external electric field, forming an electric dipole moment. The polarized dielectric particles are arranged into a chain-like partial structure along the direction of the electric field due to the dipole interaction. The general force conditions of the abrasive particles 31 in the chain-like partial structure are analyzed to obtain the force conditions of the abrasive particles 31 in the chain-like partial structure.

[0092] More specifically, the acquisition of the polishing area that predicts material removal includes:

[0093] According to material removal theory, the workpiece surface in the polishing area where material removal occurs must undergo plastic deformation. Therefore, it is necessary to ensure that the force applied to the abrasive particles 31 in the polishing area exceeds the shearing force of the workpiece 4. The relationship between the force applied to the abrasive particles 31 and their position is analyzed to determine the maximum effective area for material removal.

[0094] According to Newton's law of motion, under the rotation of the tool head, the abrasive particles 31 need to overcome the centrifugal force to produce an effect, and obtain the maximum action area to overcome the centrifugal force;

[0095] The maximum area of ​​action for overcoming centrifugal force is compared with the maximum area of ​​action for producing material removal, and the theoretical polishing area is the intersection of the maximum area of ​​action for overcoming centrifugal force and the maximum area of ​​action for producing material removal. Example 6

[0096] like Figures 1-6 As shown, based on the fourth embodiment, a polishing area prediction method of an electrorheological polishing device with multi-layer electrodes is adopted in step S5. The polishing area prediction method is implemented by the electrorheological polishing device with multi-layer electrodes, and includes the following steps:

[0097] Based on the relationship between the electric field strength and position of the polishing device, the relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field strength and the concentration of the solid phase particles in the polishing liquid, and the force conditions of the abrasive particles 31 in the chain structure, the polishing area where material can be removed is predicted.

[0098] Specifically, obtaining the relationship between the electric field strength and the position of the polishing device includes:

[0099] According to the physical model of the electrode, Coulomb's law is used to calculate the electric field intensity at one point, and then the continuous charge distribution integral method is used to obtain the relationship between the electric field intensity and position of the polishing device.

[0100] The electrode consists of a needle electrode 18 and a ring electrode 19. The electrode model is as follows: Figure 7 As shown, the center of the upper end surface of the electrode is the origin O of the coordinate system, O1 is the center of the lower end surface of the electrode, the X axis coincides with the center line of the electrode, and the distance L between O and O1 is the length of the integrated electrode. Let point P be any point in the coordinate system, and its coordinates are ( , , ), the electric field intensity at point P is equal to the sum of the electric field intensities of the central electrode and the ring electrode at that point. First, calculate the electric field intensity of the needle electrode 18: first calculate the electric field intensity of the central electrode at a certain point P, take the derivative on the X axis, and set its coordinates as ( , 0, 0), and is obtained by Coulomb's law. Since the electric field is a vector, it is necessary to calculate the electric field strength in the three directions of XYZ separately:

[0101] ;

[0102] in, is the dielectric constant in vacuum, is the charge, is the linear density, is the distance from point P to another reference point O1 on the X-axis, which can be obtained by the following formula: ; , , are the coordinate values ​​of point P in the X, Y and Z directions respectively. is the distance between the upper and lower end surfaces of the electrode, and x is the value of the infinitesimal element in the X direction;

[0103] Will Integrate to find the component of the electric field intensity in the X direction at point P: X

[0104] ;

[0105] Similarly, find the components of the electric field intensity at point P in the Y and Z directions:

[0106] ;

[0107] ;

[0108] The electric field strength of the ring electrode 19 is calculated. The ring electrode 19 is composed of three ring electrodes. Take a surface differential element ds, whose end face coordinates are (x, y, z), and the distance to point P is r1, which can be obtained by the following formula:

[0109] ;

[0110] The electric field strength in the XYZ directions is obtained using the continuous charge distribution integration method as follows:

[0111] ;

[0112] ;

[0113] ;

[0114] in, 、 、 are the linear densities of ring electrode 1, ring electrode 2, and ring electrode 3, respectively; R1, R2, and R3 are the radii of ring electrode 1, ring electrode 2, and ring electrode 3, respectively; is the differential angle.

[0115] Since the central electrode is the negative electrode, the second ring electrode is the negative electrode, and the first ring electrode and the third ring electrode are both positive electrodes, the algorithm for calculating the total electric field strength by superposition is:

[0116] Electric field strength in the X direction: ;

[0117] Electric field strength in the Y direction: ;

[0118] Electric field strength in Z direction: ;

[0119] Total electric field strength: .

[0120] Specifically, obtaining the relationship between the viscosity of the polishing liquid that produces the electrorheological effect, the electric field strength, and the concentration of the solid phase particles in the polishing liquid includes:

[0121] Based on the viscosity of the base liquid and the volume fraction of the solid phase particles in the polishing liquid, the initial viscosity before the electric field is applied is calculated; the increased viscosity of the polishing liquid after the electric field is applied is analyzed, and the initial viscosity and the increased viscosity are added to obtain the apparent viscosity of the polishing liquid under the action of the electric field. The relationship between the apparent viscosity and the electric field intensity and the volume fraction of the solid phase particles in the polishing liquid is obtained, and the relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field intensity and the concentration of the solid phase particles in the polishing liquid is obtained.

[0122] According to the viscosity of the base liquid in the polishing liquid and the volume fraction of the solid phase particles, the initial viscosity before the electric field is applied can be calculated: the initial viscosity of the polishing liquid It can be expressed as the following equation: ;

[0123] in, Viscosity coefficient, is the viscosity of the base fluid, is the volume fraction of solid particles in the suspension, is the maximum volume fraction of solid particles in the suspension.

[0124] Apparent viscosity increase of electrorheological fluid after applying electric field:

[0125] ;

[0126] in, is the apparent viscosity coefficient, is the total electric field strength, is the shear rate of the polishing fluid.

[0127] The apparent concentration of the polishing fluid can be expressed as the initial viscosity The viscosity increases with the addition of an electric field The relationship between the apparent viscosity, the electric field intensity and the volume fraction of the solid phase particles in the polishing liquid is obtained by adding the values ​​of

[0128] .

[0129] Specifically, obtaining the force conditions of the abrasive particles 31 in the chain structure includes:

[0130] According to the dipole model, in the electrorheological fluid, the dielectric particles are polarized under the action of an external electric field, forming an electric dipole moment. The polarized dielectric particles are arranged into a chain-like partial structure along the direction of the electric field due to the dipole interaction. The general stress conditions of the abrasive particles 31 in the chain-like partial structure are analyzed to obtain the stress conditions of the abrasive particles 31 in the chain-like structure.

[0131] According to the dipole model, in the electrorheological fluid, the dielectric particles are polarized under the action of an external electric field, forming an electric dipole moment. The polarized particles are arranged into chain-like distributions along the direction of the electric field due to the dipole interaction. By analyzing the interaction force of the abrasive particles 31 in the chain distribution with other particles, the first The force on the first abrasive particle 31 is divided into three parts: The force of the abrasive particles on the same layer 31 on the The force of the abrasive particles on the same chain 31 on the The force of the abrasive particles.

[0132] ER particles The algorithm for the force of each abrasive particle includes:

[0133] ;

[0134] in, is the relative dielectric constant of the base fluid, For the The electric dipole moment of the abrasive particles, is the electric dipole moment of the jth abrasive particle, is the radius of the ER particle, is the radius of the abrasive particle, is the gap distance between two adjacent ER particles.

[0135] Electric dipole moment calculation formula: ;

[0136] in, is the relative permittivity of the dispersed phase, is the relative dielectric constant of the base fluid, is the distance between the two particles.

[0137] Abrasive particles 31 on the same layer Calculation of the force of each abrasive particle:

[0138] ;

[0139] Wherein, m is the number of abrasive particles contained in a layer, and k represents the kth abrasive particle in the mth layer; For the The electric dipole moment of each abrasive particle, is the electric dipole moment of the kth abrasive particle on the same layer.

[0140] Abrasive particles on the same chain 31 to the first Calculation of the force of each abrasive particle:

[0141] ;

[0142] Where n is the number of layers in a chain, Indicates the first layer, For the first Abrasive particles; For the The electric dipole moment of each abrasive particle.

[0143] The force acting on a single abrasive particle 31 can be expressed as the sum of the three, in the general form:

[0144] .

[0145] More specifically, the acquisition of the polishing area that predicts material removal includes:

[0146] According to the material removal theory, the surface of the workpiece in the polishing area where material removal occurs must undergo plastic deformation. Therefore, it is necessary to ensure that the force applied to the abrasive particles 31 in the polishing area exceeds the shearing force of the workpiece 4. The relationship between the force applied to the abrasive particles 31 and their position is analyzed to obtain the maximum action area where material removal occurs.

[0147] According to material removal theory, the surface of the workpiece in the polishing area where material removal occurs must undergo plastic deformation. This ensures that the force applied to the abrasive particles 31 in the polishing area exceeds the shear resistance of the workpiece 4. Particle polarization, chain formation, and the formation of a stable structure cause the electrorheological fluid to exhibit a shear yield stress. These phenomena are all caused by the applied electric field. Therefore, the electric field strength has a significant impact on the yield stress. The yield stress calculation formula for the electrorheological fluid is:

[0148] ;

[0149] in, is the volume fraction of solid particles in the suspension, is the dielectric constant of vacuum, is the relative dielectric constant of the base fluid, is the maximum tilt angle at which the formed particle chain breaks, is the correction factor, is the dielectric mismatch coefficient ( ), is the relative permittivity of the dispersed phase.

[0150] Only when the cutting depth reaches a certain value and the workpiece surface undergoes plastic deformation and produces indentations under the action of the abrasive can material removal occur on the workpiece surface. Figure 8 In the polishing liquid, the abrasive particles 31 are under normal pressure. Under the action of the abrasive particles 31, the abrasive particles 31 contact the workpiece surface to produce an indentation. When the polishing liquid acts on the abrasive particles 31, the abrasive particles 31 move along the workpiece surface. Greater than the shearing force on the workpiece surface When the workpiece is cut, the surface material will be removed.

[0151] Algorithm for calculating Brinell hardness of materials:

[0152] ;

[0153] in, is the abrasive particle diameter, is the diameter of the indentation projection area, is the normal pressure on the abrasive.

[0154] from Figure 8 The contact relationship between the abrasive particles 31 and the workpiece 4 is obtained by the formula for the projected area of ​​the abrasive particles 31 on the work surface:

[0155] ;

[0156] The normal pressure on the abrasive particles 31 is mainly the hydrodynamic pressure. The calculation method is:

[0157] ;

[0158] in, is the tool head rotation angular velocity, is the polishing gap height, is the total electric field strength.

[0159] When the prepared polishing liquid is constant, the coefficient 、 is also a constant, expressed as:

[0160] ;

[0161] ;

[0162] in, Viscosity coefficient, is the viscosity of the base fluid, is the volume fraction of solid particles in the suspension, is the maximum volume fraction of solid particles in the suspension, is the radius of the central electrode, is the radius of the outermost ring electrode.

[0163] The shear force of the polishing liquid on the abrasive particles 31 is calculated as:

[0164] ;

[0165] in, is the projected area of ​​the abrasive particles on the workpiece surface, It is the projected area of ​​the indentation area of ​​the abrasive particles on the workpiece surface. is the shear yield stress of the polishing fluid;

[0166] When an indentation is formed between the abrasive particles 31 and the workpiece surface, the workpiece 4 will generate a reaction force on the abrasive particles 31. The anti-shear force calculation of the workpiece surface is: ;in, is the shear strength of the workpiece surface.

[0167] The shear force on the abrasive particles 31 when pressed into the workpiece surface is calculated as:

[0168] ;

[0169] judge Is it greater than 0? If it is greater than 0, it means that the material can be removed. Solving the above equation as an unknown number, we can get a boundary condition ; The maximum effective area for material removal.

[0170] According to Newton's law of motion, when the tool head rotates, the abrasive particles 31 need to overcome the centrifugal force to produce an effect, thereby obtaining a maximum action area for overcoming the centrifugal force.

[0171] According to Newton's laws of motion, as the tool head rotates, the abrasive particles 31 must overcome centrifugal force to exert their force. This allows us to determine the maximum area of ​​centrifugal force. This requires special consideration, specifically the force analysis of the abrasive particles 31 at the boundary. This analysis reveals that the abrasive particles 31 at the boundary are only subject to the force exerted by the ER particles on one side. The algorithm includes the following:

[0172] ;

[0173] The algorithm for the abrasive particles 31 at the boundary to be subjected to the force exerted on them by the abrasive particles 31 in the same chain on only one side includes:

[0174] ;

[0175] The algorithm for the abrasive particles 31 to be subjected to the centrifugal force includes: ;in, is the mass of a single abrasive particle, is the rotation speed of the tool spindle.

[0176] Constructing expressions includes: ,ensure If it is not less than 0, it can provide centripetal force, and the minimum effective area is , It is the area with the greatest effect to overcome centrifugal force.

[0177] Compare the maximum area of ​​action to overcome centrifugal force with the maximum area of ​​action to produce material removal, and the theoretical polishing area is the intersection of the maximum area of ​​action to overcome centrifugal force and the maximum area of ​​action to produce material removal. Then, the effective area is and The intersection of .

[0178] Working principle:

[0179] The present invention provides a multi-layer electrode electrorheological polishing device and its use and polishing area prediction method. The multi-layer electrode structure is used. Compared with the traditional double-layer electrode, the multi-layer electrode has a greater electric field strength and stronger shear yield resistance, which improves the strength of the flexible polishing head 29. The multi-layer electrode structure makes the electric field lines distributed tightly, and a large number of abrasive particles are in contact with the workpiece surface, thereby improving polishing efficiency and reducing production costs.

[0180] The electrorheological polishing device with multi-layer electrodes of the present invention can be installed on a CNC machining center. Combined with a multi-degree-of-freedom precision machining center, it can perform ultra-precision polishing of complex trajectories on the workpiece 4, and has a good polishing effect. In the polishing area covered by the multi-layer electrode structure of the present invention, the electric field strength distribution is more uniform. The design of the multi-layer electrode expands the polishing range and further improves the polishing efficiency. The device of the present invention is designed to be integrated, with a simple structure and is relatively convenient to install and disassemble. The use of a conductive slip ring 11 in the present invention can solve the problem of wire winding caused by the rotation of the tool shaft 10. The device of the present invention is highly applicable, and multi-layer electrodes of different shapes and sizes can be selected according to the workpiece. The multi-layer electrode structure part is easy to disassemble from the tool shaft 10 and is convenient to replace.

[0181] The above specific implementation methods are specific support for the scheme ideas proposed in the present invention, and cannot be used to limit the scope of protection of the present invention. Any equivalent changes or equivalent modifications made on the basis of this technical scheme in accordance with the technical ideas proposed in the present invention still fall within the scope of protection of the technical scheme of the present invention.

Claims

1. A method for predicting the polishing area of ​​an electrorheological polishing device having a multi-layer electrode, characterized in that: An electrorheological polishing device with a multi-layer electrode comprises: a polishing tool acting in an electrorheological polishing fluid, the polishing tool comprising: a supporting fixed plate, a motor being provided on one side of the supporting fixed plate, the other side of the supporting fixed plate being fixedly mounted to one end of a sleeve, the other end of the sleeve being provided with a lower end cover, the lower end cover being provided with a conductive slip ring; the motor being rotatably connected to one end of a tool shaft, the other end of the tool shaft being connected to an electrode fixing sleeve after passing through the sleeve and the conductive slip ring; a needle-shaped electrode and a ring electrode being provided on the electrode fixing sleeve, the needle-shaped electrode and the ring electrode being connected to a power supply via a conductive slip ring; the needle-shaped electrode and the multi-layer ring electrode being interconnected with each other at intervals of one layer; the outermost layer of the multi-layer ring electrode being connected to the positive electrode of the power supply via a conductive slip ring, and the innermost layer of the needle-shaped electrode being connected to the negative electrode of the power supply via a conductive slip ring; adjacent needle-shaped electrodes and multi-layer ring electrodes having different polarities; The polishing area prediction method is implemented using an electrorheological polishing device with multi-layer electrodes. The polishing area prediction method includes the following steps: The polishing area where material removal is possible is predicted based on the relationship between the electric field strength and position of the polishing device, the relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field strength, the concentration of the solid phase particles in the polishing liquid, and the force applied to the abrasive particles in the chain structure. The relationship between the electric field strength and position of the polishing device is obtained by: According to the physical model of the electrode, the electric field intensity at one point is calculated using Coulomb's law, and then the relationship between the electric field intensity and position of the polishing device is obtained using the continuous charge distribution integral method; The relationship between the viscosity of the polishing liquid that produces the electrorheological effect and the electric field strength and the concentration of the solid phase particles in the polishing liquid is obtained by: Based on the viscosity of the base liquid and the volume fraction of the solid phase particles in the polishing liquid, the initial viscosity before the electric field is applied is calculated; the increased viscosity of the polishing liquid after the electric field is applied is analyzed, and the apparent viscosity of the polishing liquid under the action of the electric field is obtained by adding the initial viscosity and the increased viscosity. The relationship between the apparent viscosity, the electric field intensity, and the volume fraction of the solid phase particles in the polishing liquid is obtained, and the relationship between the viscosity of the polishing liquid that produces the electrorheological effect, the electric field intensity, and the concentration of the solid phase particles in the polishing liquid is obtained; The acquisition of the force conditions of abrasive particles in forming a chain structure includes: According to the dipole model, in the electrorheological fluid, the dielectric particles are polarized under the action of an external electric field, forming an electric dipole moment. The polarized dielectric particles are arranged into a chain-like structure along the direction of the electric field due to the dipole interaction. The general force conditions of the abrasive particles in the chain-like structure are analyzed to obtain the force conditions of the abrasive particles in the chain-like structure. The acquisition of the polishing area that will result in material removal is predicted to include: According to the material removal theory, the workpiece surface in the polishing area where material removal occurs must undergo plastic deformation. This requires ensuring that the force on the abrasive particles in the polishing area exceeds the shearing force of the workpiece. The relationship between the force on the abrasive particles and their position is analyzed to determine the maximum area where material removal occurs. According to Newton's law of motion, when the tool head rotates, the abrasive particles need to overcome the centrifugal force to produce an effect, and obtain the maximum action area to overcome the centrifugal force; Compare the maximum area of ​​action to overcome centrifugal force with the maximum area of ​​action to produce material removal, and the theoretical polishing area is the intersection of the maximum area of ​​action to overcome centrifugal force and the maximum area of ​​action to produce material removal; The effective area is and The intersection of ; Constructing expressions includes: ,ensure If it is not less than 0, it can provide centripetal force, and the minimum effective area is , The area with the maximum effect of overcoming centrifugal force; The shear force applied to the abrasive particles when pressed into the workpiece surface is calculated as: ； judge Is it greater than 0? If it is greater than 0, it means that the material can be removed. Solving the above equation as an unknown number yields a boundary condition ; To produce the maximum effective area for material removal; in, It is the shear force exerted on the abrasive particles when pressed into the workpiece surface; The abrasive particles at the boundary are only subjected to the force from the abrasive particles in the same chain on one side; The abrasive particles at the boundary are only subjected to the force exerted by the ER particles on one side; It is the shear force of the polishing fluid acting on the abrasive particles; is the shear resistance of the workpiece surface; It is the centrifugal force that abrasive particles are subjected to; is the shear strength of the workpiece surface; is the shear yield stress of the polishing fluid; It is the projected area of ​​the abrasive particles on the workpiece surface; It is the projected area of ​​the indentation area of ​​the abrasive particles on the workpiece surface.

2. The polishing area prediction method of an electrorheological polishing device having a multi-layer electrode according to claim 1, characterized in that: The tool shaft is rotatably connected to the sleeve through a bearing group, and the sleeve is coaxially sleeved outside the tool shaft; the bearing group includes an angular contact bearing and a deep groove ball bearing embedded in the sleeve, and the angular contact bearing and deep groove ball bearing are sleeved on the tool shaft at intervals.

3. The polishing area prediction method of an electrorheological polishing device having a multi-layer electrode according to claim 2, characterized in that: A mounting cavity for inserting the tool shaft is reserved in the sleeve, and a connecting ring is provided in the mounting cavity; An installation area 1 for accommodating a coupling is reserved between the connecting ring platform and the supporting fixing plate, one end of the coupling is connected to the rotating shaft of the motor, and the other end of the coupling is connected to one end of the tool shaft; A second installation area for embedding the angular contact bearing and the deep groove ball bearing is reserved between the connecting ring and the lower end cover.

4. The polishing area prediction method of an electrorheological polishing device having a multi-layer electrode according to claim 3, characterized in that: The tool shaft is provided with a first step and a second step; one side of the angular contact bearing is in contact with the second step, one side of the deep groove ball bearing is in contact with the first step, and the other side of the deep groove ball bearing is in contact with one side of the connecting ring; The inner wall and outer wall of the deep groove ball bearing are respectively in contact with the inner wall of the sleeve and the outer wall of the tool shaft.

5. The polishing area prediction method of an electrorheological polishing device having a multi-layer electrode according to claim 4, characterized in that: A retaining spring is installed on the tool shaft; a pair of angular contact bearings are installed on the tool shaft; two sides of the angular contact bearings are respectively in contact with the second step and the retaining spring.

6. The polishing area prediction method of an electrorheological polishing device having a multi-layer electrode according to claim 5, characterized in that: The electrode fixing sleeve is threadedly connected to the tool shaft; and / or, the gap between the needle-shaped electrode and the multi-layer ring electrode is 1 mm; and / or, the tool shaft is interference fit with the inner ring of the conductive slip ring; And / or, the power supply is a high voltage DC power supply; And / or, one end of the needle electrode and the ring electrode is connected to the electrode fixing sleeve; the other end of the needle electrode and the ring electrode is immersed in the electrorheological polishing fluid and close to the workpiece in the electrorheological polishing fluid.

7. The polishing area prediction method of an electrorheological polishing device having a multi-layer electrode according to claim 6, characterized in that: In the electrode model, the center of the upper end surface of the electrode is the origin O of the coordinate system, O1 is the center of the lower end surface of the electrode, the X axis coincides with the center line of the electrode, and the distance L between O and O1 is the length of the integrated electrode; Let point P be any point in the coordinate system, whose coordinates are ( , , ), the electric field intensity at point P is equal to the sum of the electric field intensities of the central electrode and the ring electrode at that point; Calculate the electric field strength of the needle electrode 18: First, find the electric field strength of the central electrode at a certain point P, take the derivative on the X axis, and set its coordinates as ( , 0, 0), obtained by Coulomb's law; Since the electric field is a vector, it is necessary to calculate the electric field strength in the XYZ directions separately: ； in, is the dielectric constant in vacuum, is the charge, is the linear density, is the distance from point P to another reference point O1 on the X-axis, which is obtained from the following formula: ; , , are the coordinate values ​​of point P in the X, Y and Z directions respectively. is the distance between the upper and lower end surfaces of the electrode, and x is the value of the infinitesimal element in the X direction; Will Integrate to find the component of the electric field intensity in the X direction at point P: ； Similarly, find the components of the electric field intensity at point P in the Y and Z directions: ； ； Calculate the electric field strength of the ring electrode. The ring electrode consists of three ring electrodes. Take a surface differential element ds, whose end face coordinates are (x, y, z), and the distance to point P is r1, which is obtained by the following formula: ； The electric field strength in the XYZ directions is obtained using the continuous charge distribution integration method as follows: ； ； ； in, 、 、 are the linear densities of ring electrode 1, ring electrode 2, and ring electrode 3, respectively; R1, R2, and R3 are the radii of ring electrode 1, ring electrode 2, and ring electrode 3, respectively; is the differential angle; The central electrode is the negative electrode, the second ring electrode is the negative electrode, and the first and third ring electrodes are both positive electrodes. The algorithm for calculating the total electric field strength by superposition is: Electric field strength in the X direction: ; Electric field strength in the Y direction: ; Electric field strength in Z direction: ; Total electric field strength: .

8. A method for using an electrorheological polishing device having a multi-layer electrode, characterized in that: The electrorheological polishing device of any one of claims 1 to 6 is used in the method for predicting a polishing area of ​​an electrorheological polishing device having a multi-layer electrode, and the polishing method comprises the following steps: Step S1, selecting a polishing path according to the shape of the workpiece to be polished; Step S2, positioning the workpiece to be polished in the processing tank by a fixture, injecting electrorheological polishing fluid into the processing tank so that the electrorheological polishing fluid immerses the workpiece to be polished; Step S3, adjusting the Z-direction position of the polishing tool so that the lower end surfaces of the needle-shaped electrode and the multi-layered ring electrode are close to the upper end surface of the workpiece, and the lower end surfaces of the needle-shaped electrode and the multi-layered ring electrode are immersed in the electrorheological polishing fluid; Step S4: Turning on the power supply to the needle-shaped electrode and the multi-layered ring electrode generates an electric field between the needle-shaped electrode and the adjacent layers of the multi-layered ring electrode. The electrorheological polishing fluid mixed with dispersed phase particles and abrasive particles at the lower ends of the needle-shaped electrode and the multi-layered ring electrode undergoes an electrorheological effect, turning into a viscous solid, thereby forming a flexible polishing head. Step S5, starting the motor of the polishing tool, the motor drives the needle electrode and the multi-layer ring electrode to rotate, and adjusting the speed of the motor to 1000-2500 r / min, while making the polishing tool polish according to the set polishing path; Step S6, polishing is completed, the power supply and the motor are turned off, the movement is stopped, and the polished workpiece is taken out.

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