A multi-energy field assisted single-point diamond turning device and a processing method thereof

Abstract

The application relates to the technical field of ultra-precision machining, in particular to a multi-energy field assisted single-point diamond turning device and a machining method thereof, which is coaxially assembled by a spindle connecting module, an electric field assisting module, a tool holder connecting module and an ultrasonic vibration module, the electric field assisting module conducts the electric field to the rotating workpiece through a conductive slip ring without winding, and the ultrasonic vibration module drives the turning tool to produce high-frequency micro-amplitude vibration through a piezoelectric ceramic group and an amplitude changer. The electric field and the ultrasonic vibration are synchronously applied to the cutting area during machining, the electric field improves the plastic removal capacity of the material based on the electroplastic effect, the ultrasonic vibration realizes intermittent cutting to reduce the cutting force and cutting heat, and the two are cooperated to inhibit tool wear and workpiece machining damage. The device is compact in structure, perfect in insulation, and independent in adjustable method parameters, and is suitable for nanoscale ultra-precision turning of hard and brittle materials, optical crystals and semiconductor materials.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision machining technology, specifically to a multi-energy field assisted single-point diamond turning device and its machining method. Background Technology

[0002] Single-point diamond turning is a core technology for the efficient fabrication of high-precision optical components and precision functional devices. It can achieve nanometer-level surface roughness and submicron-level shape accuracy, and is widely used in high-end manufacturing fields such as aerospace, infrared optics, and advanced electronics. As key components develop towards higher precision, higher surface integrity, and higher reliability, traditional single-point diamond turning suffers from problems such as high cutting forces, high cutting temperatures, severe tool wear, easy brittle fracture removal of materials, and severe damage to the machined surface and subsurface when machining hard and brittle materials, iron-based materials, and high-hardness alloys. It is difficult to meet the stringent requirements of modern high-end equipment for the precision and performance of parts.

[0003] To improve the cutting process and enhance machining quality, scholars both domestically and internationally have proposed energy field-assisted machining methods such as ultrasonic vibration-assisted cutting and electric field-assisted cutting. Ultrasonic vibration-assisted single-point diamond turning achieves intermittent cutting by applying high-frequency micro-amplitude vibrations to the tool or workpiece. This significantly reduces cutting forces, decreases friction between the tool and workpiece, suppresses built-up edge and chipping damage, and improves material plasticity removal. However, ultrasonic vibration alone only optimizes the cutting process from a mechanical perspective and cannot fundamentally change the material's mechanical properties. In machining some high-hardness and high-brittle materials, problems such as low removal efficiency and short tool life still exist. Electric field-assisted machining, based on the electroplastic effect, changes the dislocation motion state within the material by applying an electric field to the cutting area, reducing the material's yield strength and enhancing its plastic deformation capacity. This reduces cutting resistance and machining damage, and to some extent, inhibits the chemical wear of diamond tools. However, electric field-assisted machining alone does not improve the cutting contact state. During continuous cutting, problems such as concentrated cutting heat, rapid tool wear, and poor chip removal still exist. Furthermore, the electric field application method and the matching between the electric field and the cutting motion are poor, making it difficult to stably achieve high-quality, high-efficiency ultra-precision machining.

[0004] To address the shortcomings of existing technologies, this invention aims to propose a multi-energy-field assisted single-point diamond turning device and its machining method. Starting from two aspects—material property control and cutting process optimization—it comprehensively improves the overall performance of ultra-precision machining of difficult-to-machine materials. It focuses on solving key problems in existing single-energy-field assisted machining, such as rapid tool wear, poor machining quality stability, and narrow material adaptability. This provides a feasible path for technological breakthroughs in the field of ultra-precision machining, meets the stringent machining requirements of modern high-end equipment for key components, and has significant engineering application value. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-energy field assisted single-point diamond turning device and its processing method, which achieves nanoscale ultra-precision turning of difficult-to-machine materials through the synergistic effect of electric field electroplasticity and ultrasonic intermittent cutting.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: A multi-energy field assisted single-point diamond turning device includes a spindle connection module, an electric field auxiliary module, a tool post connection module, and an ultrasonic vibration module; The spindle connection module is configured to be fixed to the machine tool spindle by negative pressure adsorption and to transmit rotational motion. The electric field auxiliary module is coaxially fixedly connected to the spindle connection module and rotates synchronously therewith. The electric field auxiliary module includes a clamping end and a conductive slip ring. The clamping end is used to clamp the workpiece, and the conductive slip ring is used to transmit the electrical signal generated by the external electric field generator to the rotating workpiece surface. The tool holder connection module is fixedly mounted on the machine tool guide rail; The ultrasonic vibration module is fixedly installed on the tool holder connection module. The ultrasonic vibration module includes a piezoelectric ceramic, an electrode plate, an amplitude transformer, and a cutting tool that are driven in sequence. The piezoelectric ceramic and the electrode plate form a piezoelectric ceramic group to convert electrical signals into mechanical vibrations, which are then amplified by the amplitude transformer to drive the cutting tool to generate high-frequency micro-amplitude vibrations. The cutting tool tip is aligned with the machining surface of the workpiece to simultaneously apply an electric field and ultrasonic vibration to the machining surface for turning.

[0007] Furthermore, the electric field-assisted module also includes: The chuck base is fixedly connected to the spindle connection module; A connecting shaft, one end of which is coaxially fixed to the chuck base, and the other end forming a hollow clamping cavity; An ER chuck is disposed within the hollow clamping cavity and is used to clamp the workpiece; A pressure cap is threaded to the end of the connecting shaft to lock the ER chuck into the hollow clamping cavity; The conductive slip ring is fixedly sleeved on the connecting shaft, and the moving terminal of the conductive slip ring passes through the reserved hole on the pressure cover and is fixedly connected to the surface of the workpiece.

[0008] Furthermore, the ER chuck is configured to be interchangeable to accommodate workpieces of different sizes.

[0009] Furthermore, the tool post connection module includes a single-row tool post and a shim. The single-row tool post is fixed to the machine tool guide rail, and the shim is disposed between the single-row tool post and the guide rail. The tool tip of the lathe tool is aligned with the rotation center of the workpiece by adjusting the thickness of the shim.

[0010] Furthermore, the ultrasonic vibration module also includes a radiating surface, which has a horizontal mating surface that is adapted to the inner wall of the tool fixture used to fix the ultrasonic vibration module, so that the tool holder on which the lathe tool is mounted remains horizontal after assembly.

[0011] Furthermore, the ultrasonic vibration module also includes a shock-absorbing layer, which is fitted onto the mating part of the ultrasonic vibration module and the tool holder connection module to buffer and isolate vibrations transmitted to the machine tool guide rail.

[0012] Furthermore, the ultrasonic vibration module is fixed to the upper end face of the single-row tool holder by secondary locking with tool handle fastening bolts.

[0013] Furthermore, the device is filled with bakelite insulator at the connection point with the machine tool, and bolt insulating sleeves are fitted on the outside of the through-type connecting bolts to achieve full-process insulation and isolation between the device and the machine tool.

[0014] On the other hand, the present invention proposes a turning method based on the above-mentioned multi-energy field assisted single-point diamond turning device, comprising the following steps: S1: Device assembly and insulation treatment: Connect the spindle connection module to the machine tool spindle using negative pressure adsorption. Sequentially complete the coaxial assembly of the electric field auxiliary module, tool post connection module, and ultrasonic vibration module. Fill the connection between the device and the machine tool with bakelite insulator and fit bolt insulating sleeves on the outside of the through-type connecting bolts. Adjust the tool tip to be level with the rotation center of the workpiece by adjusting the shims. S2: Workpiece clamping and electric field conduction: Clamp the workpiece at the clamping end of the electric field auxiliary module, fix the moving terminal of the conductive slip ring to the workpiece surface, connect the stationary terminal to the external electric field generator, and turn on the electric field generator to apply an electric field in the cutting area. S3: Ultrasonic vibration debugging. Connect the piezoelectric ceramic and electrode plate of the ultrasonic vibration module to the external electrical signal. Turn on the electrical signal to make the piezoelectric ceramic group composed of the piezoelectric ceramic and electrode plate generate mechanical vibration. After being amplified by the amplitude transformer, it drives the cutting tool to generate high-frequency micro-amplitude vibration. S4: Cooperative turning process, start the machine tool spindle to drive the workpiece to rotate, control the turning tool to feed along the set cutting path relative to the machining surface of the workpiece, and perform turning process under the condition of applying electric field and ultrasonic vibration on the machining surface at the same time; S5: Finishing process, shut down the machine tool spindle, electric field generator and ultrasonic vibration drive in sequence, and unload the workpiece.

[0015] Furthermore, in step S4, the simultaneous application of the electric field and ultrasonic vibration improves the plastic removal capacity of the workpiece material in the cutting area and reduces the cutting force and cutting heat. The electric field parameters applied in step S2, the ultrasonic vibration parameters applied in step S3, and the cutting parameters in step S4 are all independently adjustable to be adapted to the different characteristics of the workpiece (5), such as hard and brittle materials, optical crystals, or semiconductor materials.

[0016] The beneficial effects of this invention are: This invention integrates electric field assistance and ultrasonic vibration into the same machining system, simultaneously applying an electric field and ultrasonic vibration in the cutting area. This synergistically improves machining efficiency from two dimensions: controlling material constitutive properties and optimizing cutting mechanics. The moving terminal of the conductive slip ring is fixed to the workpiece surface, directly and without entanglement introducing the electric field into the rotating workpiece. A stable electric field is formed in the tool tip contact area, reducing the dislocation motion activation energy and lowering the material yield strength. This promotes the removal of hard and brittle materials through plastic flow, suppressing brittle fracture and subsurface microcracks at the source. Simultaneously, the piezoelectric ceramic assembly drives the cutting tool to generate high-frequency micro-amplitude vibration via an amplitude transformer, transforming continuous cutting into intermittent cutting with periodic tool-chip separation. This reduces the average cutting resistance, and the separation gap improves cooling and lubrication while suppressing built-up edge. The reduced deformation resistance from the electric field decreases the energy consumption and cutting heat of a single ultrasonic vibration cut. The intermittent nature and cooling effect of ultrasonic vibration also suppress the tool chemical wear and diffusion wear exacerbated by increased plasticity. The synergy of these two factors further reduces cutting force, significantly extends tool life, achieves nanometer-level precision in the machined surface, and reduces subsurface damage.

[0017] In this invention, the conductive slip ring and ER chuck are coaxially integrated on the connecting shaft in the electric field-assisted module. They are fixed to the spindle connection module via the chuck base, achieving stable transmission of electrical signals to the rotating workpiece and unified high-rigidity, high-coaxiality workpiece clamping. The mover terminal passes through the pre-drilled hole in the pressure cap and is directly fixed to the workpiece surface, ensuring uniform electric field distribution in the cutting zone unaffected by workpiece contour changes. The mating surfaces of the device with the machine tool spindle and guide rails are filled with bakelite insulators, and through-type connecting bolts are fitted with bolt insulating sleeves, forming full-process electrical isolation from the machine tool body to the rotating workpiece. This blocks the path of electric field leakage through the machine tool's metal components, eliminates electromagnetic interference to the CNC system, and ensures the electrical safety and reliability of electric field-assisted machining.

[0018] In this invention, the horizontal mating surface on the outer periphery of the ultrasonic vibration module's radiation surface adheres to the inner wall of the tool fixture, forming circumferential positioning. This restricts the module's rotation around its axis, ensuring the tool holder and cutting tool maintain a horizontal orientation after assembly and eliminating cutting angle errors caused by assembly deflection. The shock-absorbing layer fitted onto the mating surface of the module and tool fixture utilizes the internal friction and relaxation effect of polymer damping material to dissipate the reverse-propagating vibration energy, attenuating the high-frequency vibration amplitude transmitted to the tool holder and machine tool guideways. This ensures the cutting tool receives sufficient vibration energy while protecting the machine tool's accuracy. Adjustable-thickness shims are placed between the single-row tool holder and the guideways, achieving equal height alignment between the cutting tool tip and the workpiece's rotation center in a simple and reliable manner. This avoids the weakening of the tool holder's rigidity by complex fine-tuning mechanisms, improving the convenience of on-site industrial debugging and the practicality of the device.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a complete structural schematic diagram of the present invention.

[0022] Figure 2 This is a schematic diagram of the electric field auxiliary module.

[0023] Figure 3 This is a schematic cross-sectional view of the electric field auxiliary module structure.

[0024] Figure 4 This is a schematic diagram of the tool holder connection module.

[0025] Figure 5 This is a schematic diagram of the vibration module structure.

[0026] Figure 6 This is a schematic cross-sectional view of the vibration module structure.

[0027] In the diagram: 1. Spindle connection module; 2. Electric field auxiliary module; 20. Chuck base; 21. Connecting shaft; 22. Conductive slip ring; 23. Pressure cap; 200. Chuck connecting bolt; 210. Connecting shaft connecting bolt; 220. Conductive slip ring fixing bolt; 221. Mover terminal; 222. Stator terminal; 230. Wiring fixing screw; 24. ER collet; 3. Tool post connection module; 30. Single-row tool post; 31. Tool fixture pressure cap; 32. Tool fixture base. 33. Shim, 300. Tool holder fixing T-nut, 301. Tool holder fastening bolt, 310. Tool fixture fastening bolt, 4. Ultrasonic vibration module, 40. Tool holder, 41. Amplitude rod, 42. Radiation surface, 43. Piezoelectric ceramic, 44. Electrode plate, 45. Rear pressure cover, 46. Connecting screw, 47. Anti-vibration layer, 48. Lathe tool, 400. Tool holder fastening bolt, 410. Amplitude rod fastening bolt, 480. Tool fastening bolt, 5. Workpiece, 6. Insulator. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0029] This embodiment provides a single-point diamond turning device and its machining method assisted by electric field and ultrasonic vibration. For example... Figure 1 As shown, in this embodiment, the multi-energy field assisted single-point diamond turning device is assembled coaxially from four parts: spindle connection module 1, electric field auxiliary module 2, tool holder connection module 3, and ultrasonic vibration module 4.

[0030] Specifically, the spindle connection module 1 is configured to be fixed to the machine tool spindle by negative pressure adsorption and transmit rotational motion. The electric field auxiliary module 2 is coaxially fixed to the lower end of the spindle connection module 1 and rotates together with it. The lower end of the electric field auxiliary module 2 is a clamping end for clamping the workpiece 5. The tool post connection module 3 is fixedly mounted on the T-shaped guide rail of the machine tool. The ultrasonic vibration module 4 is fixedly mounted on the upper end of the tool post connection module 3, and a turning tool 48 is mounted on its front end. The tip of the turning tool 48 is aligned with the machining surface of the workpiece 5 to simultaneously apply an electric field and ultrasonic vibration to the machining surface for turning.

[0031] like Figure 2 and Figure 3 As shown, in this embodiment, the electric field auxiliary module 2 is specifically composed of a chuck base 20, a connecting shaft 21, a conductive slip ring 22, a pressure cap 23, and an ER chuck 24.

[0032] The chuck base 20 is a disc-shaped base, and its upper end face is fixedly connected to the flange at the lower end of the main shaft connecting module 1 by chuck connecting bolts 200. The center position of the lower end face of the chuck base 20 is coaxially fixed to the upper end of the cylindrical connecting shaft 21 by connecting shaft connecting bolts 210 to ensure coaxiality during overall rotation.

[0033] A hollow clamping cavity is machined inside the lower end of the connecting shaft 21, and the ER chuck 24 is placed inside this cavity. The pressure cap 23 is screwed onto the lower end of the connecting shaft 21. During tightening, the inner conical surface of the pressure cap 23 pushes against the outer conical surface of the ER chuck 24, forcing the ER chuck 24 to contract radially, thereby firmly clamping the workpiece 5 inserted therein. In this embodiment, by replacing the ER chuck 24 with different specifications, this device can be adapted to clamp workpieces 5 of different diameters or lengths, improving the versatility and material adaptability of the device.

[0034] A conductive slip ring 22 is fixedly sleeved on the outer circumference of the connecting shaft 21 and is kept relatively fixed to the connecting shaft 21 by conductive slip ring fixing bolts 220. The conductive slip ring 22 includes a moving part that can rotate synchronously with the connecting shaft 21 and a stationary part that remains stationary. The moving part terminal 221 extends downward along the axial direction of the connecting shaft 21 from the moving part, passes through a reserved hole opened in the side wall or end face of the pressure cover 23, and is directly fixed and connected to the surface of the workpiece 5 by the wiring fixing bolts 230. The stationary part terminal 222 extends outward from the stationary part for connecting to an external electric field generator. When the machine tool spindle rotates, the electrical signal is input from the stationary stationary part terminal 222, transmitted to the rotating moving part terminal 221 through the contactless conduction mechanism inside the conductive slip ring 22, and finally applied stably and without winding to the surface of the workpiece 5.

[0035] like Figure 4 , Figure 5 and Figure 6 As shown, in this embodiment, the tool holder connection module 3 includes a single-row tool holder 30, a tool fixture cover 31, a tool fixture base 32, and a pad 33.

[0036] The single-row tool post 30 is a strip-shaped base component. Its bottom is slidably engaged and locked to the T-shaped guide rail of the machine tool via a tool post fixing T-nut 300. A shim 33 is placed between the bottom surface of the single-row tool post 30 and the top surface of the machine tool guide rail. In this embodiment, by selecting or modifying shims 33 of different thicknesses, the installation height of the single-row tool post 30 can be precisely adjusted, thereby ensuring that the tip of the cutting tool 48 mounted on it is aligned with the rotation center of the workpiece 5 at the same height.

[0037] The tool fixture base 32 is fixed to the upper surface of the single-row tool holder 30 by bolts. The upper surface of the tool fixture base 32 has a semi-circular or V-shaped groove that matches the outer contour of the ultrasonic vibration module 4. The ultrasonic vibration module 4 is placed in this groove, and the tool fixture cover 31 is fastened to the top of the ultrasonic vibration module 4 and securely connected to the tool fixture base 32 by tool fixture fastening bolts 310, thereby firmly holding and fixing the ultrasonic vibration module 4. Furthermore, the ultrasonic vibration module 4 is also further locked and fixed to the upper surface of the single-row tool holder 30 by tool holder fastening bolts 301, effectively suppressing any micro-displacement that may be caused by high-frequency vibration.

[0038] The ultrasonic vibration module 4 is a slender cylindrical structure containing a piezoelectric drive assembly. Specifically, the rear end of the module houses a piezoelectric ceramic assembly composed of multiple piezoelectric ceramic pieces 43 and electrode plates 44 stacked alternately. A connecting screw 46 passes through the central hole of the piezoelectric ceramic assembly and the electrode plates 44, its front end threadedly connected to the radiating surface 42, and its rear end is pressed by a rear pressure cap 45 to create a preload. The radiating surface 42 is located at the front end of the piezoelectric ceramic assembly, and its output end is coaxially fixed to the input end of the amplitude transformer 41 via an amplitude transformer fastening bolt 410. The amplitude transformer 41 is stepped or exponentially curved, and its output end is fixedly connected to the tool holder 40 via a tool holder fastening bolt 400. The front end of the tool holder 40 has a tool groove, in which a lathe tool 48 is placed and locked in place by a tool fastening bolt 480.

[0039] In this embodiment, a horizontal mating surface is specially machined on the outer periphery of the radiating surface 42. When the ultrasonic vibration module 4 is clamped between the tool fixture cover 31 and the tool fixture base 32, the horizontal mating surface fits against the inner wall of the fixture, playing a circumferential positioning role and ensuring that the tool holder 40 and the cutting tool 48 always maintain a strictly horizontal posture after assembly.

[0040] A shock-absorbing layer 47 is fitted around the outer periphery of the ultrasonic vibration module 4 at the location where it mates with the tool fixture. In some embodiments, the shock-absorbing layer 47 is made of rubber; in other embodiments, it may also be made of a polymer damping material such as polyurethane or silicone. The shock-absorbing layer 47 buffers and absorbs the high-frequency vibration energy transmitted from the ultrasonic vibration module 4 to the tool holder connection module 3 and the machine tool guideway, thereby reducing the impact of vibration on the accuracy of the machine tool guideway.

[0041] In this embodiment, to ensure the safety of the electric field-assisted machining process, the device adopts full-process insulation isolation measures. Specifically, the contact surfaces between the device and the machine tool, including but not limited to the contact surfaces between the machine tool guide rail and the tool post connection module 3, and the flange contact surfaces between the spindle box and the spindle connection module 1, are all filled with bakelite insulators 6. Simultaneously, all connecting bolts penetrating each component (such as chuck connecting bolts 200, tool post fixing T-nuts 300, etc.) are fitted with bolt insulating sleeves. Through this double insulation design, reliable electrical isolation between the device and the machine tool body is achieved.

[0042] Based on the above-described apparatus, this embodiment also provides a turning process, comprising the following steps: S1: Assembly and Insulation: Connect the spindle connection module 1 to the machine tool spindle end face using negative pressure adsorption. Complete the coaxial assembly of the electric field auxiliary module 2, tool post connection module 3, and ultrasonic vibration module 4 sequentially. Fill each connection point between the device and the machine tool with bakelite insulator 6, and cover the outside of all through-type connecting bolts with bolt insulating sleeves. Adjust the tip height of the cutting tool 48 by adjusting or selecting the thickness of the shims 33 until it is precisely aligned with the rotation center of the workpiece 5 to be processed.

[0043] S2: Workpiece clamping and electric field conduction: Select an ER chuck 24 that matches the diameter of workpiece 5, insert workpiece 5 into the inner hole of the chuck, and tighten the pressure cap 23 to lock it in place. Fix the moving terminal 221 of the conductive slip ring 22 to the end face of workpiece 5 using the wiring fixing bolt 230. Connect the stator terminal 222 to the output terminal of the external electric field generator. Turn on the electric field generator and adjust the electric field parameters (such as voltage, current, frequency, or DC / AC mode) according to the workpiece material characteristics to form a stable auxiliary electric field in the cutting area.

[0044] S3: Ultrasonic Vibration Adjustment: Connect the lead wires of the electrode plate 44 of the ultrasonic vibration module 4 to the external ultrasonic power supply. Turn on the ultrasonic power supply and adjust the electrical signal parameters (such as frequency, amplitude, and power) to cause the piezoelectric ceramic 43 to generate high-frequency mechanical vibration under the inverse piezoelectric effect. This vibration is amplified by the amplitude transformer 41 and drives the cutting tool 48 to generate high-frequency micro-amplitude vibration along the cutting direction or elliptical trajectory.

[0045] S4: Cooperative Turning: Start the machine tool spindle, driving the workpiece 5 to rotate at the set speed. Control the tool post connection module 3 to drive the ultrasonic vibration module 4 and the turning tool 48 to feed relative to the machining surface of the workpiece 5 along the preset cutting path. Turning is performed under the condition of simultaneously applying an electric field and ultrasonic vibration on the machining surface. In this cooperative process, the electric field reduces the yield strength of the workpiece material through the electroplastic effect, improves its plasticity removal ability, and inhibits brittle fracture; the ultrasonic vibration makes the cutting process a high-frequency intermittent cutting, effectively reducing the average cutting force and cutting temperature. Compared with machining methods assisted by a single electric field or a single ultrasonic vibration, the cooperative effect of this embodiment can significantly inhibit the chemical wear of diamond tools, reduce chipping damage on the workpiece surface, thereby obtaining higher machining surface quality and longer tool life.

[0046] S5: Finishing the machining: After the cutting process is completed, turn off the output of the machine tool spindle rotation, electric field generator, and ultrasonic vibration drive in sequence. After the device has completely stopped operating, loosen the pressure cover 23, remove the machined workpiece 5, and clean and perform necessary maintenance on each module of the device.

[0047] It should be understood that the technical solutions of the present invention are not limited to the forms described in the specific embodiments above.

[0048] In other embodiments of the present invention, the electric field parameters in step S2 include voltage amplitude and frequency, the ultrasonic vibration parameters in S3 include vibration frequency and amplitude, and the cutting parameters in S4 include spindle speed, feed rate, and depth of cut. All of these parameters are independently adjustable. The operator can flexibly set and optimize the combination of process parameters based on the specific material type of the workpiece 5, such as hard and brittle materials like silicon carbide and glass, optical crystals like calcium fluoride and zinc selenide, or semiconductor materials like single-crystal silicon and germanium, and considering the different physical and chemical properties of these materials, thereby obtaining the best surface finish and efficiency.

[0049] It should be understood that although workpiece 5 is clamped by ER chuck 24 in this embodiment, those skilled in the art can use other forms of mechanical chucks or vacuum chucks to clamp the workpiece without departing from the core concept of this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

[0050] In summary, this invention proposes a multi-energy field assisted single-point diamond turning device and its machining method. It consists of a spindle connection module, an electric field auxiliary module, a tool holder connection module, and an ultrasonic vibration module coaxially assembled. The electric field auxiliary module transmits the electric field to the rotating workpiece without winding through a conductive slip ring. The ultrasonic vibration module drives the cutting tool to generate high-frequency micro-amplitude vibration through a piezoelectric ceramic assembly and an amplitude transformer. During machining, the electric field and ultrasonic vibration are simultaneously applied to the cutting area. The electric field enhances the material's plasticity removal capacity based on the electroplastic effect, while the ultrasonic vibration enables intermittent cutting to reduce cutting force and heat. Together, they suppress tool wear and workpiece damage. This device has a compact structure, excellent insulation, and independently adjustable method parameters, making it suitable for nanoscale ultra-precision turning of hard and brittle materials, optical crystals, and semiconductor materials.

[0051] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A multi-energy field assisted single-point diamond turning device, comprising a spindle connection module (1), an electric field auxiliary module (2), a tool holder connection module (3), and an ultrasonic vibration module (4), characterized in that, The spindle connection module (1) is configured to be fixed to the machine tool spindle by negative pressure adsorption and to transmit rotational motion; The electric field auxiliary module (2) is coaxially fixedly connected to the main spindle connection module (1) and rotates synchronously therewith. The electric field auxiliary module (2) includes a clamping end and a conductive slip ring (22). The clamping end is used to clamp the workpiece (5), and the conductive slip ring (22) is used to transmit the electrical signal generated by the external electric field generator to the rotating surface of the workpiece (5). The tool holder connecting module (3) is fixedly mounted on the machine tool guide rail; The ultrasonic vibration module (4) is fixedly installed on the tool holder connection module (3). The ultrasonic vibration module (4) includes a piezoelectric ceramic (43), an electrode plate (44), an amplitude transformer (41), and a cutting tool (48) that are driven in sequence. The piezoelectric ceramic (43) and the electrode plate (44) form a piezoelectric ceramic group to convert electrical signals into mechanical vibrations, which are then amplified by the amplitude transformer (41) to drive the cutting tool (48) to generate high-frequency micro-amplitude vibrations. The tip of the cutting tool (48) is aligned with the machining surface of the workpiece (5) so that an electric field and ultrasonic vibration are applied simultaneously on the machining surface for turning.

2. The multi-energy field assisted single-point diamond turning device as described in claim 1, characterized in that, The electric field-assisted module (2) also includes: The chuck base (20) is fixedly connected to the spindle connection module (1); The connecting shaft (21) has one end coaxially fixed with the chuck base (20), and the other end forms a hollow clamping cavity; ER chuck (24) is disposed in the hollow clamping cavity and is used to clamp the workpiece (5). The pressure cap (23) is threaded to the end of the connecting shaft (21) to lock the ER chuck (24) in the hollow clamping cavity; The conductive slip ring (22) is fixedly sleeved on the connecting shaft (21). The moving terminal (221) of the conductive slip ring (22) passes through the reserved hole on the pressure cover (23) and is fixedly connected to the surface of the workpiece (5).

3. The multi-energy field assisted single-point diamond turning device as described in claim 2, characterized in that, The ER chuck (24) is configured to be interchangeable to accommodate workpieces (5) of different sizes.

4. The multi-energy field assisted single-point diamond turning device as described in claim 1, characterized in that, The tool post connection module (3) includes a single-row tool post (30) and a shim (33). The single-row tool post (30) is fixed to the machine tool guide rail. The shim (33) is placed between the single-row tool post (30) and the guide rail. The thickness of the shim (33) is adjusted to make the tip of the lathe tool (48) and the rotation center of the workpiece (5) equal and aligned.

5. The multi-energy field assisted single-point diamond turning device as described in claim 1, characterized in that, The ultrasonic vibration module (4) also includes a radiation surface (42), which has a horizontal mating surface. The horizontal mating surface is adapted to the inner wall of the tool fixture used to fix the ultrasonic vibration module (4) so ​​that the tool holder (40) on which the lathe tool (48) is installed remains horizontal after assembly.

6. The multi-energy field assisted single-point diamond turning device as described in claim 1, characterized in that, The ultrasonic vibration module (4) also includes a shock-absorbing layer (47), which is fitted on the mating part of the ultrasonic vibration module (4) and the tool holder connection module (3) to buffer and isolate the vibration transmitted to the machine tool guide rail.

7. The multi-energy field assisted single-point diamond turning device as described in claim 1, characterized in that, The ultrasonic vibration module (4) is fixed to the upper surface of the single-row knife holder (30) by secondary locking with the knife handle fastening bolt (301).

8. The multi-energy field assisted single-point diamond turning apparatus as described in any one of claims 1 to 7, characterized in that, The device is filled with bakelite insulator (6) at the connection point with the machine tool, and bolt insulating sleeve is fitted on the outside of the through-type connecting bolt to achieve full-process insulation isolation between the device and the machine tool.

9. A turning method based on the multi-energy field assisted single-point diamond turning apparatus according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1: Assembly and insulation of the device: Connect the spindle connection module (1) to the machine tool spindle by negative pressure adsorption, and complete the coaxial assembly of the electric field auxiliary module (2), the tool post connection module (3) and the ultrasonic vibration module (4) in sequence. Fill the connection part between the device and the machine tool with bakelite board insulator (6) and put bolt insulating sleeve on the outside of the through-type connecting bolt. Adjust the tool tip of the lathe tool (48) and the rotation center of the workpiece (5) to be processed by adjusting the shim (33). S2: Workpiece clamping and electric field conduction: clamp the workpiece (5) at the clamping end of the electric field auxiliary module (2), fix the moving terminal (221) of the conductive slip ring (22) to the surface of the workpiece (5), connect the stationary terminal (222) to the external electric field generator, and turn on the electric field generator to apply an electric field in the cutting area. S3: Ultrasonic vibration debugging, connect the piezoelectric ceramic (43) and electrode plate (44) of the ultrasonic vibration module (4) to the external electrical signal, turn on the electrical signal to make the piezoelectric ceramic group composed of piezoelectric ceramic (43) and electrode plate (44) generate mechanical vibration, which is amplified by the amplitude transformer (41) and drives the cutting tool (48) to generate high frequency micro-amplitude vibration; S4: Cooperative turning process, start the machine tool spindle to drive the workpiece (5) to rotate, control the cutting tool (48) to feed along the set cutting path relative to the machining surface of the workpiece (5), and perform turning process under the condition of applying electric field and ultrasonic vibration on the machining surface at the same time; S5: Finishing the machining process, shut down the machine tool spindle, electric field generator and ultrasonic vibration drive in sequence, and unload the workpiece (5).

10. The turning method as described in claim 9, characterized in that, In step S4, the simultaneous application of the electric field and ultrasonic vibration improves the plastic removal capacity of the workpiece (5) material in the cutting area and reduces the cutting force and cutting heat. The electric field parameters applied in step S2, the ultrasonic vibration parameters applied in step S3, and the cutting parameters in step S4 are all independently adjustable to be adapted to the different characteristics of the workpiece (5), such as hard and brittle materials, optical crystals, or semiconductor materials.

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