Laser-ultrasonic hybrid cutting device

Abstract

This invention provides a laser-ultrasonic composite cutting device, comprising a laser module, an ultrasonic elliptical vibration module, a light-guided diamond tool, and a temperature control and active cleaning system. The laser module is located behind the ultrasonic elliptical vibration module and is used to emit laser light. The laser light irradiates the light-guided diamond tool through the central through-hole of the ultrasonic elliptical vibration module. The laser module is mounted on a three-way fine-tuning device, which is used for laser position calibration and fine-tuning to ensure that the laser light can be focused at a predetermined position. The ultrasonic elliptical vibration module is a dual-excitation longitudinal-bending ultrasonic vibration module. The longitudinal ultrasonic vibration and bending ultrasonic vibration form an ultrasonic elliptical vibration trajectory in the cutting plane and are transmitted to the diamond tool through the light-guided tool holder. The light-guided diamond tool is connected to the output end of the ultrasonic elliptical vibration module through the light-guided tool holder. The diamond tool has a reflective light path design to ensure that when using diamond tools with a 0 rake angle or a small negative rake angle, the laser light is still refracted out by the diamond rake face.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision special machining technology, and in particular to a laser-ultrasonic composite cutting device. Background Technology

[0002] The application of energy field-assisted machining in the field of ultra-precision machining provides a technical feasibility for the ultra-precision machining of difficult-to-machine materials. It has broad application prospects, especially for difficult-to-machine hard and brittle materials (such as semiconductor materials and optical crystal materials).

[0003] Laser-assisted cutting technology focuses a high-energy laser beam onto the workpiece's cutting area, raising the temperature of the cutting zone to an appropriate value, reducing material hardness, increasing its cutting deformation capacity, and decreasing cutting force, thereby achieving better machinability. Currently, traditional laser-assisted cutting generally suffers from excessive distance between the laser spot and the tool. To ensure the cutting zone temperature, a high-power laser is required, resulting in high energy consumption. Furthermore, a high-power laser spot easily generates a large stress field, leading to surface damage in brittle materials. The influence of the cutting fluid on the laser beam path also increases the uncertainty of the laser focusing position. Therefore, laser in-situ assisted turning devices have been designed to effectively avoid these problems, as described in invention patents [CN 111069767 B] and [CN 108818983 A]. However, existing designs for the internal laser micro-path of diamond cutting directly inject the laser beam from the rear end of the tool and focus it at the tool tip. This design is suitable for tools with a large negative rake angle, but when the rake angle is small or zero degrees, the laser beam undergoes total internal reflection at the tool's rake face and only refracts through the flank face, affecting the laser modification effect. As shown in the attached figure [CN 108818983 A], when the current angle α is 10°, β takes the maximum value of 24° (otherwise total reflection will occur at the rake face). At this time, AC is still much smaller than AD, and this structure is obviously not suitable for diamond tools.

[0004] Compared to one-dimensional ultrasonic vibration cutting, ultrasonic elliptical vibration cutting has the advantages of "friction reversal", "variable angle cutting", and more thorough "tooling". Features such as "workpiece separation" effectively extend tool life, improve cutting surface finish and cutting stability, and suppress burrs and regenerative chatter. Although the intermittent cutting characteristics of ultrasonic elliptical vibration cutting greatly suppress chemical wear of diamond tools, for machining hard and brittle materials, the high-frequency impact between the tool and the material can easily lead to physical wear such as chipping of the diamond tool.

[0005] Furthermore, the patent document disclosed in CN114178676A uses a non-circular amplitude transformer to passively convert longitudinal-bending vibration. Its elliptical trajectory is fixed and cannot be adjusted according to material properties. When machining different hard and brittle materials, the amplitude transformer needs to be replaced, making the operation cumbersome and unable to achieve ultra-precision machining where the surface shape error is less than or equal to the required amplitude transformer replacement. The patent document disclosed in CN119635319A only achieves 0-angle laser emission through pitch adjustment of the laser emission module, resulting in a long adjustment cycle and inability to adapt to small negative rake angles below -10°. While CN114799933A can adapt to small negative rake angles, the inner reflective surface weakens the tool rigidity, and the lack of ultrasonic composite technology leads to a high tool breakage rate. In addition, in existing technologies, the heat accumulation in laser-ultrasonic composite cutting causes the tool temperature to reach at least 80°C, making diamond prone to graphitization. Cutting fluid splashing causes contamination of the tool's rear end face, reducing light transmittance and resulting in severe laser energy loss, ultimately failing to meet actual machining requirements for surface roughness. Summary of the Invention

[0006] To address the aforementioned technical problems and achieve a synergistic effect (1+1>2) by combining the advantages of ultrasonic elliptical vibration cutting and laser-assisted cutting, this invention proposes a laser-ultrasonic composite cutting device with strong practicality. This invention integrates ultrasonic-assisted and laser-assisted cutting, suppressing tool wear from both physical and chemical perspectives, thereby improving machining quality. Compared to existing ultrasonic-laser composite cutting systems, this invention not only highly integrates the ultrasonic and laser systems but also innovatively designs a diamond tool reflection optical path to ensure that laser energy applied to tools with 0 rake angle or small negative rake angles is refracted from the tool tip rake face, resulting in greater practicality. The technical means employed in this invention are as follows:

[0007] A laser-ultrasonic composite cutting device includes a laser module, an ultrasonic elliptical vibration module, a light-guided diamond tool, and a temperature control and active cleaning system. The laser module is located behind the ultrasonic elliptical vibration module and is used to emit laser light. The laser light shines on the light-guided diamond tool through the central through-hole of the ultrasonic elliptical vibration module. The laser module is mounted on a three-way fine-tuning device, which is used for laser position calibration and fine-tuning to ensure that the laser light can be focused at a predetermined position. The ultrasonic elliptical vibration module is a dual-excitation longitudinal bending ultrasonic vibration module. The longitudinal ultrasonic vibration and bending ultrasonic vibration form an ultrasonic elliptical vibration trajectory in the cutting plane and are transmitted to the diamond tool through the light-guided tool holder. The diamond tool has a reflective light path design to ensure that when using diamond tools with 0 rake angle and small negative rake angle, the laser light can still be refracted from the diamond rake face to achieve effective modification of the material.

[0008] The temperature control and active cleaning system includes an embedded microchannel thermostatic subsystem and a diamond rear face dual-mode cleaning subsystem.

[0009] The embedded microfluidic thermostatic subsystem includes: a carbide tool base with an integrated serpentine microfluidic channel, a condenser tube, a cooling medium storage tank, and an outlet micro check valve and an inlet micro check valve; the serpentine microfluidic channel is formed by laser welding and sealing two pre-machined micro-grooves of carbide substrates; the condenser tube is covered with metal fins, one end of which is connected to the outlet of the serpentine microfluidic channel, and the other end is connected to the cooling medium storage tank; the outlet micro check valve and the inlet micro check valve are respectively located at the outlet and inlet of the microfluidic channel to achieve unidirectional flow.

[0010] The dual-mode cleaning subsystem for the rear face of the diamond cutter includes: an equalizing water pipe, a resistance temperature sensor, a controller, an electromagnetic reversing valve, and a high-pressure air source; the equalizing water pipe is located on the upper right side of the light-guiding diamond cutter and is used to spray high-pressure gas or a gas-liquid mixture; the resistance temperature sensor is attached to the side of the light-guiding diamond cutter; the controller is electrically connected to the temperature sensor and the electromagnetic reversing valve, and the electromagnetic reversing valve is used to switch the path between the high-pressure air source and the cleaning liquid.

[0011] Furthermore, the output end of the laser module is equipped with a focusing lens, which is used to focus the light spot diameter to 50. 150°, the fine-tuning accuracy of the three-way fine-tuning device is 0.001mm, the power of the laser module is less than 200W, and the output power can be adjusted to meet the processing needs of different materials.

[0012] Furthermore, the ultrasonic elliptical vibration module includes two orthogonally arranged longitudinal ultrasonic vibration units. Longitudinal ultrasonic vibration unit A is fixed to longitudinal ultrasonic vibration unit B by fastening bolts, and excites bending vibration of longitudinal ultrasonic vibration unit B. Combined with the longitudinal vibration of longitudinal ultrasonic vibration unit B itself, a longitudinal-bending ultrasonic elliptical vibration in the cutting plane is synthesized. Both longitudinal ultrasonic vibration units consist of a fastening bolt cover plate, a circular piezoelectric ceramic sheet, a copper electrode, and a stepped amplitude transformer.

[0013] Furthermore, the annular piezoelectric ceramic sheet is of model PZT. 4. Utilizing the high efficiency of the ring-shaped piezoelectric ceramic in the d33 working mode, ultrasonic longitudinal vibration is output.

[0014] Furthermore, the total length of longitudinal ultrasonic vibration unit A is equal to the wavelength of longitudinal vibration at the same frequency. The first annular piezoelectric ceramic stack is located at the crest of the longitudinal vibration and is used to excite the longitudinal ultrasonic vibration of the device. The total length of longitudinal ultrasonic vibration unit B is equal to two wavelengths of longitudinal vibration and four wavelengths of bending vibration at the same frequency. The second annular piezoelectric ceramic stack is located at the crest of the longitudinal vibration and is used to excite and generate longitudinal ultrasonic vibration. Longitudinal ultrasonic vibration unit A is fixed to the stepped amplitude transformer of longitudinal ultrasonic vibration unit B by fastening bolts, with the contact point at the crest of bending vibration to excite and generate bending ultrasonic vibration. Combined with the aforementioned longitudinal ultrasonic vibration, it forms longitudinal-bending ultrasonic elliptical vibration.

[0015] Furthermore, the longitudinal ultrasonic vibration unit B is provided with a through hole to allow the introduction of inert gas, ensuring that the through hole is not blocked and that the rear end face of the diamond is smooth.

[0016] Furthermore, the diamond tool has a reflective surface at the bottom. The laser is incident from the back end of the diamond tool, undergoes total internal reflection through the reflective surface, and is refracted out from the front face. An anti-reflection film is added to the back end face of the tool, and a reflective film is added to the reflective surface.

[0017] Furthermore, the laser power calibrator is used to verify the power and energy density of the laser beam emitted from the tool.

[0018] Furthermore, the jet nozzle is located to the right rear of the tool's rear end face, and the angle between the jet nozzle of the equalizing water pipe and the rear end face of the light-guiding diamond tool is 30°~60°, with a jet nozzle diameter of 0.5~1mm.

[0019] Furthermore, the controller is configured to: when the temperature sensor detects that the tool temperature exceeds the cleaning threshold, trigger the electromagnetic reversing valve to conduct the cleaning liquid, forming a mixture with a gas-liquid volume ratio of 1:5 to 1:8; when the temperature is below the cleaning threshold, only high-pressure gas is conducted to form a positive pressure environment.

[0020] This invention organically integrates ultrasonic elliptical vibration-assisted cutting, single-point diamond cutting technology, and micro-laser-assisted machining technology, improving processing efficiency and accuracy while extending tool life. Furthermore, the device can flexibly switch between the laser and ultrasonic modules to adapt to different processing needs.

[0021] The present invention has the following advantages:

[0022] 1. This composite assisted cutting system combines ultrasonic elliptical vibration cutting technology with laser-assisted cutting technology, giving full play to the advantages of both technologies. It can effectively solve problems such as tool chipping caused by high-frequency impacts during machining of hard and brittle materials, and graphitization wear of diamond tools due to excessive heat in laser-assisted cutting.

[0023] 2. Compared with the prior art, the cutting tool in this invention is designed with a reflective surface, which can ensure that the laser can still be refracted from the front cutting surface when the laser on the current cutting surface is at a small negative rake angle or 0.

[0024] 3. The amplitude of ultrasonic vibration can be adjusted by the ultrasonic power supply; the ultrasonic elliptical vibration trajectory can be controlled by optimizing the amplitude transformer structure; and the power and spot size of the laser beam can also be continuously adjusted by the laser generator, providing a basis for ultrasonic... The optimization of laser-assisted cutting technology has provided a foundation and made the composite assisted cutting system more adaptable.

[0025] 4. The temperature control and active cleaning system of this invention eliminates the need for external compressed air sources and external cutting fluid pumps, reducing the overall weight of the structure. Simultaneously, the serpentine microchannel directly contacts the tool base, rapidly removing heat from the base through medium circulation, effectively reducing thermal expansion and thus completely eliminating machining deviations caused by base deformation. The cleaning structure effectively treats contamination on the rear face of the light guide diamond, reducing laser energy loss and improving laser energy utilization. It also effectively avoids the risk of diamond graphitization at high temperatures, extending the tool's lifespan. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the module structure in an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the internal structure of the module in an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the light guide knife holder structure in an embodiment of the present invention.

[0030] Figure 4 , Figure 5 These are schematic diagrams of the internal optical paths of two different cutting tools in embodiments of the present invention.

[0031] Figure 6 This is a schematic diagram of the temperature control and active cleaning system.

[0032] In the diagram, 1 is the laser module, 2 is the ultrasonic elliptical vibration module, 3 is the light-guiding diamond, 4 is the laser power meter, 5 and 12 are both PZT-4 ring-shaped piezoelectric ceramics, 6 and 11 are both copper electrodes, 7 and 10 are the rear cover plates of the ultrasonic vibration unit, 8 and 9 are both fastening bolts, 13 and 14 are both stepped amplitude transformers, 15 is the vent, 16 is the three-way fine-tuning device, 17 is the tool height adjustment mechanism, 18 is the diamond light-guiding tool holder, and 19 is the tool holder fastening. Position, 20. Light guide channel; 22. Laser channel; 23. Laser beam; 24. Ultrasonic vibration unit; 25. Tool body; 26. Outlet micro check valve; 27. Metal fin heat sink; 28. Storage tank; 29. ​​Inlet micro check valve; 30. Tool body; 31. Microflow channel; 32. Resistance temperature sensor; 33. Controller; 34. Electromagnetic directional valve; 35. Cleaning liquid; 36. High-pressure gas source; 37. High-pressure gas / gas-liquid mixture. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0034] This invention discloses a laser An ultrasonic vibration coupled assisted cutting system includes a laser module 1, an ultrasonic elliptical vibration module 2, a light-guided diamond tool 3, and a temperature control and active cleaning system. The ultrasonic elliptical vibration module has a through-hole at its center. The laser module emits laser light. A three-way fine-tuning device is connected to the laser module to adjust its position, allowing the laser beam to pass through the light-guided tool holder and strike the light-guided diamond tool during operation. The ultrasonic elliptical vibration module consists of two orthogonally placed longitudinal ultrasonic vibration units, outputting longitudinal-bending elliptical ultrasonic vibration in the cutting plane. The light-guided diamond tool is mounted on the light-guided tool holder, which is connected to the output end of the ultrasonic elliptical vibration cutting output mechanism. The ultrasonic elliptical vibration cutting output end drives the light-guided diamond tool to complete ultrasonic elliptical vibration cutting. The light-guided diamond tool has a special optical path design; the incident laser undergoes a series of refractions and reflections through this special optical path structure before being refracted out through the rake face. The tool height adjustment mechanism is connected to the ultrasonic elliptical vibration cutting module and is used to perform tool setting operations on the light-guided diamond tool during cutting.

[0035] Specifically, such as Figure 1 As shown, a laser of the present invention The ultrasonic synchronous assisted cutting system includes a laser module 1, an ultrasonic elliptical vibration cutting module 2, a light-guiding diamond tool 3, a three-dimensional fine-tuning device 16, and a tool height adjustment mechanism 17.

[0036] like Figure 1 and 2 As shown, the laser module emits a laser spot with a diameter of 50 mm. The laser module 1 has a diameter of 150 μm and can adjust the power of the emitted laser beam to adapt to the characteristics and requirements of different processing materials.

[0037] like Figure 1 and 2 As shown, the laser module 1 is fixedly connected to the three-dimensional displacement fine-tuning mechanism 16. The three-dimensional displacement fine-tuning mechanism 16 adjusts the position of the laser beam so that it passes through the groove 20 opened on the light guide tool holder 18 and is incident on the rear end face of the light guide diamond tool 3, with an adjustment accuracy of 1μm. By designing and optimizing the geometric features of the light guide diamond tool 3, the incident laser beam is reflected and refracted before being emitted from the front face of the light guide diamond tool 3 and focused on the cutting area before the workpiece material is removed, thus softening it. The laser power calibrator 4 can verify the power and energy density of the laser beam emitted from the tool.

[0038] When a beam of light enters a medium with a lower refractive index n1 from a medium with a higher reflectivity, refraction will occur, and the refraction law is as follows: The air refractive index n1 = 1.

[0039] like Figure 4 As shown, in embodiment A, the tool rake angle is 0°:

[0040] θ1=∠ABD=∠DBC(1)

[0041] θ2+2θ1=π / 2(2)

[0042] When a beam of light enters a medium with a lower refractive index n1 from a medium with a higher reflectivity, refraction will occur, and the refraction law is as follows: The air refractive index n1 = 1.

[0043] To prevent total internal reflection at the rake face, which would prevent the laser beam from refracting out of the rake face, θ2 and θ1 need to satisfy a certain numerical relationship, i.e., θ2 < θ1. r =arcsin(1 / n2). Take n2=2.417, that is, θ2<24°, θ1>33°.

[0044] like Figure 5 As shown, in embodiment B, the tool rake angle is ≠ 0°:

[0045] θ2+2θ1=π / 2(3)

[0046] θ2+2θ5=θ3(4)

[0047] To avoid total internal reflection at the rake face, which would prevent the laser beam from refracting out, θ2 and θ1 need to satisfy a certain numerical relationship, namely θ5 < θr = arcsin(1 / n2). Taking n2 = 2.417, that is, θ5 < 24°, 2θ1 + θ3 < 138°.

[0048] Let the rake angle α of the tool be 0° to -30°, and the angle θ between the reflecting surface and the bottom surface satisfy:

[0049] θ=90° 1 / 2 (24.72°-α)

[0050] When α = 0°, θ = 0°2: the laser is incident at an angle of 62° on the reflecting surface (> the critical angle of 24.72°, total internal reflection), and incident at an angle of 18° on the rake face (< the critical angle, refracted emission). When α = -30°, θ = 30°, the laser is incident at an angle of 67° on the reflecting surface and at an angle of 22° on the rake face, still avoiding total internal reflection. This configuration achieves a laser emission rate of ≥92% at a small negative rake angle, and the reflecting surface is located in the non-cutting edge area at the bottom of the tool, significantly improving rigidity.

[0051] like Figure 1 and 2 As shown, the ultrasonic elliptical vibration cutting module includes PZT-4 annular piezoelectric ceramics 5 and 12, copper electrodes 6 and 11, ultrasonic vibration unit rear cover plates 7 and 10, fastening bolts 8 and 9, stepped amplitude transformers 13 and 14, and a vent 15. Specifically, the ultrasonic vibration unit rear cover plate 7, copper electrodes 6, and PZT-4 annular piezoelectric ceramics 5 are mounted on the stepped amplitude transformer 14 using fastening bolts 8, and the ultrasonic vibration unit rear cover plate 10, copper electrodes 11, and PZT-4 annular piezoelectric ceramics 12 are mounted on the stepped amplitude transformer 13 using fastening bolts 9. The stepped amplitude transformer 13 and the stepped amplitude transformer 14 are orthogonally connected.

[0052] like Figure 2 As shown, the ultrasonic elliptical vibration module includes two orthogonally arranged longitudinal ultrasonic vibration units. Each longitudinal ultrasonic vibration unit is sequentially connected and secured by a bolted back cover plate, a circular piezoelectric ceramic plate, a copper electrode, and a stepped amplitude transformer. All components should be cleaned with anhydrous ethanol and dried in a forced-air drying oven before assembly. The circular piezoelectric ceramic plate is of model PZT. 4. Utilizing the high efficiency of the d33 working mode of the annular piezoelectric ceramic, ultrasonic longitudinal vibration is output. In this embodiment, the total length of longitudinal ultrasonic vibration unit A is equal to one longitudinal wavelength, with the first piezoelectric ceramic stack (PZT-4) located at the wave crest. The total length of unit B is equal to two longitudinal wavelengths plus four bending wavelengths, with the second piezoelectric ceramic stack located at both the longitudinal and bending wave crests. The two units are orthogonally fixed, and the ratio of the major axis to the minor axis of the synthesized elliptical trajectory is adjustable from 1:1 to 2:1. In the prior art, the conversion of the irregularly shaped amplitude transformer is passive and cannot actively control the vibration trajectory. The dual-excitation longitudinal-bending design of this invention achieves wavelength matching of the two orthogonal longitudinal units, piezoelectric ceramic stack position calibration, and repeated adjustment of amplitude fluctuations using a laser vibrometer, ensuring the amplitude fluctuation is within an accuracy of ±0.1μm.

[0053] like Figure 2 As shown, the total length of longitudinal ultrasonic vibration unit A is equal to the wavelength of longitudinal vibration at the same frequency. The first annular piezoelectric ceramic stack is located at the crest of the longitudinal vibration and is used to excite the longitudinal ultrasonic vibration of the device. The total length of longitudinal ultrasonic vibration unit B is equal to two wavelengths of longitudinal vibration and four wavelengths of bending vibration at the same frequency. The second annular piezoelectric ceramic stack is located at the crest of the longitudinal vibration and is used to excite and generate longitudinal ultrasonic vibration. Longitudinal ultrasonic vibration unit A is fixed to the stepped amplitude transformer of longitudinal ultrasonic vibration unit B by fastening bolts. The contact point is at the crest of bending vibration, which excites and generates bending ultrasonic vibration. Combined with the aforementioned longitudinal ultrasonic vibration, it forms longitudinal-bending ultrasonic elliptical vibration.

[0054] The longitudinal ultrasonic vibration unit B has a through hole at its center for conducting the laser beam. High-strength bolts are used to constrain the amplitude transformer 14 and the rear cover plate 7 to the support frame, which is connected to a tool height adjustment device. This device allows for fine-tuning of the displacement of the light-guiding diamond tool, with an adjustment accuracy of 0.1 micrometers. This enables precise tool setting during cutting and improves cutting accuracy.

[0055] The longitudinal ultrasonic vibration unit B has a vent hole 15 at its thin end, which is connected to the through hole to allow inert gas to be introduced, ensuring that there is no blockage inside the through hole and that the diamond rear end face is smooth.

[0056] like Figure 6 As shown, the temperature control and active cleaning system includes an embedded microchannel thermostatic subsystem and a diamond rear face dual-mode cleaning subsystem;

[0057] The embedded microfluidic thermostatic subsystem includes: a cemented carbide tool base 30 with an internally integrated serpentine microfluidic channel 31, a condenser tube, a cooling medium storage tank 28, and an outlet micro-check valve 26 and an inlet micro-check valve 29. The serpentine microfluidic channel 31 is formed by laser welding two pre-machined micro-grooves on a cemented carbide substrate. Specifically, a serpentine micro-groove is first machined on the surface of the cemented carbide, and then combined with another piece of cemented carbide to form a tool base, thereby forming a microfluidic channel. The two alloys are sealed by laser welding. The cross-section of the microfluidic channel is circular. The condenser tube is covered with metal fins 27, one end of which is connected to the outlet of the microfluidic channel 31, and the other end is connected to the cooling medium storage tank 28. There are two micro-check valves 26 and 29, which are respectively located at the inlet and outlet of the microfluidic channel 31 to achieve unidirectional flow.

[0058] The dual-mode cleaning subsystem for the rear face of the diamond includes: an equalizing water pipe, a resistance temperature sensor 32, a controller 33, an electromagnetic reversing valve 34, and a high-pressure air source 36; the equalizing water pipe is located on the upper right side of the light-guiding diamond 3 and is used to spray high-pressure gas or a gas-liquid mixture 37; the resistance temperature sensor 32 is attached to the side of the light-guiding diamond 3; the controller 33 is electrically connected to the temperature sensor 32 and the electromagnetic reversing valve 34; the electromagnetic reversing valve 34 is used to switch the path between the high-pressure air source 36 and the cleaning liquid 35.

[0059] Furthermore, the cross-section of the serpentine microchannel 31 is circular with a diameter of 2-4 mm, and the total length of the microchannel is 3-4 times the length of the tool base 30.

[0060] Furthermore, the opening pressure threshold of the micro check valves 26 and 29 is 0.05~0.2MPa.

[0061] Furthermore, the condenser tube is an aluminum capillary tube with an inner diameter of 3-5 mm and a wall thickness of 1-1.5 mm. The metal fins 27 are fixed to the outer wall of the condenser tube by brazing, with a fin spacing of 1-3 mm and a height of 10-20 mm.

[0062] Furthermore, the jet nozzle is located to the right rear of the tool's rear end face, the angle between the jet nozzle of the equalizing water pipe and the rear end face of the light-guiding diamond 3 is 30°~60°, and the diameter of the jet nozzle is 0.5~1mm.

[0063] Furthermore, the controller 33 is configured to: when the temperature sensor 32 detects that the tool temperature exceeds the cleaning threshold, trigger the electromagnetic reversing valve 34 to conduct the cleaning liquid 35 to form a mixture 37 with a gas-liquid volume ratio of 1:5 to 1:8; when the temperature is below the cleaning threshold, only the high-pressure gas 36 is conducted to form a positive pressure environment.

[0064] Furthermore, the cooling medium is a mixture of water and ethylene glycol, wherein the volume percentage of ethylene glycol is 30% to 50%. In this embodiment, the cooling medium is a water-ethylene glycol mixture with a freezing point of -30°C. This can cover cutting environments ranging from -20°C to 100°C. Simultaneously, the high specific heat capacity of the medium ensures a gradual temperature rise after absorbing heat from the base, reducing the frequency of phase change cycles and extending system life. The system can operate stably in cold workshops or under high-temperature cutting conditions, exhibiting strong environmental adaptability. Of course, as other optional implementation methods, other cooling media can be selected according to actual working conditions.

[0065] Furthermore, it also includes an ultrasonic vibration unit and / or a laser channel to be suitable for single laser or ultrasonic conditions or laser-ultrasonic composite cutting, wherein the ultrasonic vibration unit is rigidly connected to the tool base 30, and the laser channel penetrates the tool base 30 and is aligned with the light guide diamond 3.

[0066] This invention also discloses a method for using the temperature control and active cleaning system for the above-mentioned self-heating ultra-precision cutting scenario, comprising the following steps:

[0067] The resistance temperature sensor 32 is tightly attached to the side of the light guide diamond 3. During the processing, the temperature data it acquires is transmitted to the controller 33.

[0068] The controller 33 is based on a preset cleaning threshold. When the detected temperature is lower than the cleaning threshold, the controller outputs a signal to make the electromagnetic reversing valve 34 only open the high-pressure gas source 36 passage and cut off the cleaning liquid 35. When the temperature is higher than the cleaning threshold, the controller switches the electromagnetic reversing valve passage to make the high-pressure gas source and the cleaning liquid open at the same time. The high-pressure gas negative pressure is used to draw in the cleaning liquid to form a mixture with a gas-liquid volume ratio of 1:5 to 1:8.

[0069] The equalizing water pipe receives the medium from the electromagnetic reversing valve. Under normal conditions, when the pressure is below the preset cleaning threshold, high-pressure gas is ejected from the nozzle, forming a positive pressure barrier on the rear end face of the light guide diamond to prevent cutting fluid from splashing and adhering. In cleaning mode, when the pressure is above the preset cleaning threshold, the gas-liquid mixture is ejected at a preset high speed, removing residual stains through the dual action of airflow impact and liquid dissolution. Simultaneously, the airflow cooling method lowers the temperature of the rear end face of the light guide diamond to a preset value. The preset high-speed ejection is adjusted based on the specific processing conditions, such as 30-80 m / s.

[0070] The preset cleaning threshold and preset value can be adjusted according to the specific processing conditions. In this embodiment, the preset cleaning threshold and preset value are 60°C.

[0071] This may also include the following steps:

[0072] Operating condition switching adaptation:

[0073] Among them, single ultrasonic cutting is: the laser channel is closed, only the ultrasonic vibration unit is turned on, and the cleaning subsystem maintains only high-pressure gas mode to avoid gas-liquid mixture from affecting metal chip removal.

[0074] Single laser cutting involves: shutting down the ultrasonic vibration unit, opening the laser channel, strengthening the circulation of the constant temperature subsystem, and switching the cleaning subsystem normally according to the temperature threshold.

[0075] Laser-ultrasonic composite cutting involves simultaneously activating the ultrasonic vibration unit and the laser channel, with the constant temperature subsystem and the cleaning subsystem operating at full capacity to ensure that base temperature control and light-guiding diamond cleaning are effective simultaneously.

[0076] The working principle and process of the embedded microfluidic constant temperature system are as follows: When the tool base 30 is heated by heat conduction, the water-ethylene glycol cooling medium in the microfluidic channel 31 undergoes underheating and boiling to generate bubbles. The internal pressure increases, pushing the outlet micro check valve 26 to open. The vaporized medium enters the condenser tube, liquefies, and flows back to the storage tank 28. After the pressure drops, the inlet micro check valve 29 opens to replenish the liquid medium, forming a closed-loop phase change cooling.

[0077] The isothermal subsystem of this invention employs a cemented carbide tool holder with an internally integrated serpentine microfluidic channel. It connects to a finned condenser and a cooling medium storage tank via inlet and outlet micro-check valves, achieving pump-free active temperature control through a self-driven phase change cycle of the water-glycol cooling medium. The cleaning subsystem uses a temperature sensor to monitor the tool status in real time. A controller triggers cleaning modes in stages based on temperature thresholds, spraying high-pressure gas and gas-liquid mixtures through pressure-equalizing water pipes and high-pressure gas pipes according to different cleaning modes. This invention eliminates cutting deviations caused by deformation of the heated tool holder through phase change boiling circulation and prevents laser energy loss and diamond graphitization risks caused by contamination. It can be applied to self-heating ultra-precision cutting scenarios such as laser-ultrasonic composite cutting and single laser / ultrasonic vibration.

[0078] During ultrasonic vibration machining, the ultrasonic vibration unit is rigidly connected to the tool base 10 through a flange to ensure that the vibration is transmitted to the light guide diamond without attenuation. At the same time, the embedded microchannel constant temperature subsystem cools the base to avoid base deformation caused by the accumulation of vibration friction heat, thus ensuring the accuracy of vibration transmission.

[0079] In laser processing, the laser channel passes through the tool base and is coaxial with the rear end face of the light guide diamond. The embedded microchannel thermostatic subsystem suppresses the thermal expansion of the base and avoids deviation in the coaxiality of the channel. The dual-mode cleaning subsystem of the diamond rear end face keeps the rear end face clean and prevents the laser from focusing deviation due to the refraction of dirt. The two work together to ensure that the laser energy accurately penetrates the light guide diamond.

[0080] When switching to single laser cutting, only the ultrasonic vibration unit is turned off, while the thermostat and cleaning subsystems remain operational, using microfluidic temperature control to adapt to the high laser temperature. When switching to single ultrasonic cutting, the laser is turned off, and the cleaning subsystem maintains only positive pressure protection to prevent liquid from affecting metal chip removal. When switching to composite cutting, all devices work together, with the thermostat controlling temperature, the cleaning subsystem providing protection, and the ultrasonic-laser transmission being precise, requiring no additional module replacement. This synergistic effect offers better adaptability and higher integration compared to traditional single processing scenarios, covering all scenarios of laser-ultrasonic composite and single laser / ultrasonic cutting for hard and brittle materials (including semiconductors, optical crystals, etc.).

[0081] The present invention features a resistance temperature sensor attached to the side of the light-guiding diamond. The controller has a preset cleaning threshold of 60°C. When the temperature is below 60°C, only the high-pressure air source is activated, forming a positive pressure barrier to prevent cutting fluid splashing. When the temperature is ≥60°C, the electromagnetic reversing valve switches to both high-pressure air and cleaning liquid, with a spray speed of 30-80 m / s. Particulate matter is removed through airflow impact, and oil stains are removed through liquid dissolution. Based on this dual effect, the light transmittance of the rear face can be restored to over 92% in a very short time. This invention introduces the phase change cycle principle from thermodynamics and the gas-liquid mixing spray principle from fluid mechanics into the field of laser-ultrasonic composite processing, solving the problems of diamond graphitization and laser energy loss.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser-ultrasonic composite cutting device, characterized in that, The system includes a laser module, an ultrasonic elliptical vibration module, a light-guided diamond cutting tool, and a temperature control and active cleaning system. The laser module, located behind the ultrasonic elliptical vibration module, emits a laser beam. The laser beam passes through a central through-hole in the ultrasonic elliptical vibration module and illuminates the light-guided diamond cutting tool. The laser module is mounted on a three-way fine-tuning device, which is used for laser position calibration and fine-tuning to ensure that the laser beam is focused at a predetermined position. The ultrasonic elliptical vibration module is a dual-excitation longitudinal bending ultrasonic vibration module. The longitudinal ultrasonic vibration and bending ultrasonic vibration form an ultrasonic elliptical vibration trajectory in the cutting plane and are transmitted to the diamond cutting tool via the light-guided tool holder. The light-guided diamond cutting tool is connected to the output end of the ultrasonic elliptical vibration module via the light-guided tool holder. The diamond cutting tool has a reflective light path design to ensure that the laser beam can still be refracted from the diamond rake face when using diamond cutting tools with a 0° rake angle or a small negative rake angle. The temperature control and active cleaning system includes an embedded microchannel thermostatic subsystem and a diamond rear face dual-mode cleaning subsystem. The embedded microfluidic thermostatic subsystem includes: a carbide tool base with an integrated serpentine microfluidic channel, a condenser tube, a cooling medium storage tank, and an outlet micro check valve and an inlet micro check valve; the serpentine microfluidic channel is formed by laser welding and sealing two pre-machined micro-grooves of carbide substrates; the condenser tube is covered with metal fins, one end of which is connected to the outlet of the serpentine microfluidic channel, and the other end is connected to the cooling medium storage tank; the outlet micro check valve and the inlet micro check valve are respectively located at the outlet and inlet of the microfluidic channel to achieve unidirectional flow. The dual-mode cleaning subsystem for the rear face of the diamond cutter includes: an equalizing water pipe, a resistance temperature sensor, a controller, an electromagnetic reversing valve, and a high-pressure air source; the equalizing water pipe is located on the upper right side of the light-guiding diamond cutter and is used to spray high-pressure gas or a gas-liquid mixture; the resistance temperature sensor is attached to the side of the light-guiding diamond cutter; the controller is electrically connected to the temperature sensor and the electromagnetic reversing valve, and the electromagnetic reversing valve is used to switch the path between the high-pressure air source and the cleaning liquid.

2. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, The output end of the laser module is equipped with a focusing lens, which is used to focus the light spot diameter to 50. The micrometer is 150μm, the micro-adjustment accuracy of the three-dimensional micro-adjustment device is 0.001mm, the power of the laser module is less than 200W, and the output power can be adjusted to meet the processing requirements of different materials.

3. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, The ultrasonic elliptical vibration module includes two orthogonally arranged longitudinal ultrasonic vibration units. Longitudinal ultrasonic vibration unit A is fixed to longitudinal ultrasonic vibration unit B by fastening bolts and excites the bending vibration of longitudinal ultrasonic vibration unit B. Combined with the longitudinal vibration of longitudinal ultrasonic vibration unit B itself, longitudinal-bending ultrasonic elliptical vibration in the cutting plane is synthesized. Both longitudinal ultrasonic vibration units are composed of a fastening bolt back cover plate, a circular piezoelectric ceramic sheet, a copper electrode, and a stepped amplitude transformer.

4. The laser-ultrasonic composite cutting device according to claim 3, characterized in that, The annular piezoelectric ceramic sheet is of model PZT.

4. Utilizing the high efficiency of the ring-shaped piezoelectric ceramic in the d33 working mode, ultrasonic longitudinal vibration is output.

5. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, The total length of longitudinal ultrasonic vibration unit A is equal to the wavelength of longitudinal vibration at the same frequency. The first annular piezoelectric ceramic stack is located at the crest of the longitudinal vibration and is used to excite the longitudinal ultrasonic vibration of the device. The total length of longitudinal ultrasonic vibration unit B is equal to two wavelengths of longitudinal vibration and four wavelengths of bending vibration at the same frequency. The second annular piezoelectric ceramic stack is located at the crest of the longitudinal vibration and is used to excite and generate longitudinal ultrasonic vibration. Longitudinal ultrasonic vibration unit A is fixed to the stepped amplitude transformer of longitudinal ultrasonic vibration unit B by fastening bolts. The contact point is at the crest of bending vibration and excites and generates bending ultrasonic vibration. Combined with the aforementioned longitudinal ultrasonic vibration, it forms longitudinal-bending ultrasonic elliptical vibration.

6. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, The longitudinal ultrasonic vibration unit B is equipped with a through hole through which inert gas is introduced to ensure that there is no blockage inside the through hole and that the rear end face of the diamond is smooth.

7. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, The diamond tool has a reflective surface at the bottom. The laser is incident from the back end of the diamond tool, undergoes total internal reflection through the reflective surface, and is refracted out from the front face. An anti-reflection film is added to the back end face of the tool, and a reflective film is added to the reflective surface.

8. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, A laser power calibrator is used to verify the power and energy density of a laser beam emitted from a cutting tool.

9. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, The jet nozzle is located to the right rear of the rear end face of the diamond. The angle between the jet nozzle of the equalizing water pipe and the rear end face of the diamond is 30°~60°, and the diameter of the jet nozzle is 0.5~1mm.

10. The laser-ultrasonic composite cutting device according to claim 1, characterized in that, The controller is configured to: when the temperature sensor detects that the tool temperature exceeds the cleaning threshold, trigger the electromagnetic reversing valve to conduct the cleaning liquid, forming a mixture with a gas-liquid volume ratio of 1:5 to 1:8; when the temperature is below the cleaning threshold, only high-pressure gas is conducted to form a positive pressure environment.

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