Ultrasonic-laser collaborative assisted milling system and processing method thereof

Abstract

The present invention provides an ultrasonic-laser collaborative assisted milling system and a processing method thereof, comprising a spindle with a built-in laser emission module, a tool handle at the end of the spindle, an ultrasonic elliptical vibration unit in the tool handle, a milling cutter at the output end of the ultrasonic elliptical vibration unit, and beam holes in the spindle, the tool handle, the ultrasonic elliptical vibration unit and the milling cutter, which are coaxial. The present invention uses a continuous laser beam to be directly transmitted through the central beam hole, and the milling cutter head acts on the workpiece processing surface, so that the continuous laser beam can be concentrated in structures such as curved surfaces, deep cavities and grooves, and the purpose of laser-assisted processing can be fully achieved, ensuring the quality of milling processing.

Description

Technical Field

[0001] The invention relates to the field of milling processing, and in particular to an ultrasonic-laser collaborative auxiliary milling system and a processing method thereof. Background Art

[0002] Hard and brittle materials, such as high-strength ceramics, cemented carbide, glass and carbon nanotubes, have a wide range of applications in aerospace, electronic information, optics, energy and other fields due to their unique physical and chemical properties. They are especially indispensable in key equipment such as high-performance radars and missile seekers. However, the high hardness, low toughness and high brittleness of these materials make the tools very easy to break and wear during processing, making it difficult to ensure processing quality and the processing efficiency is low. Therefore, the problem of efficient and precise processing of hard and brittle materials has become a key problem that needs to be solved in the manufacturing industry.

[0003] Energy field-assisted processing technology, as an effective solution for hard, brittle and difficult-to-process materials, has attracted much attention in my country's processing and manufacturing industry in recent years, and its application scope is becoming increasingly wide. Among them, ultrasonic vibration-assisted processing and laser-assisted processing have become two iconic advanced processing technologies with their excellent performance and effectiveness. Ultrasonic vibration-assisted processing technology significantly improves the machinability of hard and brittle materials by reducing the friction coefficient during the processing process and enhancing the plastic flow of materials; while laser-assisted processing technology, with its high energy density, high precision and non-contact characteristics, can effectively soften the workpiece material, reduce the mechanical wear of the tool, and greatly improve the processing efficiency, showing unique advantages in the field of precision processing of hard and brittle materials.

[0004] Ultrasonic-laser collaborative assisted milling technology integrates the advantages of two single energy field assisted processing, while effectively avoiding the problems of low efficiency of ultrasonic vibration assisted processing and easy generation of thermal stress and burns of workpieces in laser assisted processing. In response to this technology, many scholars at home and abroad have also developed various styles of ultrasonic-laser composite cutting equipment, such as patent CN215941632U, patent applications with publication numbers CN113798563A and CN116140680A, which can all realize ultrasonic-laser composite processing functions.

[0005] However, although this type of processing equipment has shown significant advantages, in actual application scenarios, the external design of the ultrasonic vibration unit and the laser emission module leads to a low degree of integration, making the overall structure relatively loose and not conducive to working in a narrow environment; and in the processing of complex structural components, the laser beam is difficult to concentrate on curved surfaces, deep cavities, grooves and other structures, resulting in the purpose of laser-assisted processing cannot be fully achieved. Summary of the invention

[0006] The main purpose of the present invention is to provide an ultrasonic-laser collaborative assisted milling system and a processing method thereof, so as to solve the problem that the auxiliary processing in the ultrasonic-laser collaborative assisted milling equipment cannot be fully realized.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] An ultrasonic-laser collaborative assisted milling system and a processing method thereof, comprising a spindle with a built-in laser emission module, a tool handle at the end of the spindle, an ultrasonic elliptical vibration unit in the tool handle, a milling cutter at the output end of the ultrasonic elliptical vibration unit, and beam holes in the spindle, the tool handle, the ultrasonic elliptical vibration unit and the milling cutter, which are coaxial.

[0009] The ultrasonic elliptical vibration unit generates ultrasonic elliptical vibration to act on the milling cutter, and the laser emission module generates a continuous laser beam that passes through the beam hole and is emitted from the head of the milling cutter, assisting the milling cutter to achieve ultrasonic-laser collaborative assisted milling processing;

[0010] The light beam hole is connected with an air pipe for air intake. A heating mechanism is arranged at the air pipe for heating the air entering the air pipe so that the air entering the light beam hole is hot air for blowing away waste chips and controlling the temperature.

[0011] In a preferred solution, the laser emission module is connected to the inside of the main shaft through a mechanical fixing device, and a fiber optic slip ring is provided at the end of the laser emission module. The output end of the fiber optic slip ring is electrically connected to the laser emission module, and the output end of the fiber optic slip ring is a rotating end. The input end of the fiber optic slip ring is connected to a laser control power supply through an optical fiber, the optical fiber passes through the end of the main shaft, and the input end of the fiber optic slip ring is a fixed end.

[0012] In a preferred embodiment, the ultrasonic elliptical vibration unit includes a fixed flange connected to the end of the tool handle, a variable amplitude rod is provided inside the tool handle, the variable amplitude rod passes through the fixed flange and extends to the outside of the tool handle, a spring chuck is connected to the head of the variable amplitude rod, a pressure cap is connected to the external thread of the spring chuck, and the tail end of the milling cutter is located inside the spring chuck;

[0013] The tail of the horn is provided with two second piezoelectric ceramics, a middle cover plate, two first piezoelectric ceramics, a rear cover plate and a pre-tightening bolt in sequence, the two second piezoelectric ceramics and the two first piezoelectric ceramics are connected with copper electrodes, the copper electrodes are attached to the second piezoelectric ceramics and the first piezoelectric ceramics, and the pre-tightening bolt passes through the second piezoelectric ceramics, the middle cover plate, the copper electrode, the first piezoelectric ceramics and the rear cover plate and is threadedly connected to the horn;

[0014] The copper electrodes are electrically connected to a dual-channel ultrasonic power supply through a wireless power transfer unit.

[0015] In a preferred embodiment, the wireless power transmission unit includes a rotating ring sleeved on the outside of the tool handle, a second ferrite coil electrically connected to the copper electrode is provided on the rotating ring, a dual-channel ultrasonic power supply is electrically connected to the first ferrite coil through a cable, the first ferrite coil is provided on a fixed ring, the first ferrite coil is electrically connected to the second ferrite coil in contact, and the fixed ring is connected to the spindle housing through a mounting frame.

[0016] In a preferred embodiment, the first piezoelectric ceramic adopts axial polarization to excite the longitudinal vibration mode of the ultrasonic elliptical vibration unit; the second piezoelectric ceramic adopts tangential polarization to excite the torsional vibration mode of the ultrasonic elliptical vibration unit, thereby realizing the longitudinal-torsional composite vibration mode of the ultrasonic elliptical vibration unit.

[0017] In a preferred solution, the main shaft is rotatably connected to the main shaft housing through a bearing, a driven gear is connected to the main shaft outer shell, an input shaft is rotatably arranged in the main shaft housing, a driving gear is fixed to the end of the input shaft, and the driving gear is meshed with the driven gear;

[0018] The input shaft is the output shaft of the milling machine.

[0019] In a preferred solution, a gas rotary joint is provided at the end of the main shaft, the input end of the gas rotary joint is connected to an external gas source device, and the input end of the gas rotary joint is a fixed end;

[0020] The output end of the gas rotary joint is connected with a gas pipe, and the output end of the gas rotary joint is a rotating end. The inner wall of the main shaft is provided with a gas pipe connection seat. The gas pipe is located inside the main shaft, and one end of the gas pipe away from the gas rotary joint is connected to the gas pipe connection seat.

[0021] An air hole is provided inside the main shaft, one end of the air hole is connected to the air pipe connection seat, and the other end of the air hole is connected to the light beam hole;

[0022] Air hole tilt setting.

[0023] In a preferred embodiment, a through hole is provided at the center of the gas rotary joint, the fixed end of the optical fiber slip ring is connected to a connecting frame, the connecting frame is connected to a conduit, the conduit is hollow, the conduit passes through the through hole, the conduit is connected to the fixed end of the gas rotary joint, and the optical fiber passes through the conduit and the connecting frame and is connected to the optical fiber slip ring.

[0024] In a preferred solution, a through hole is provided in the connecting frame; the heating mechanism includes a conductive slip ring provided outside the conduit, the fixed end of the conductive slip ring is connected to the connecting frame, and the external connection line of the conductive slip ring passes through the conduit and is externally connected to the power supply device and the control device;

[0025] A fixed sleeve is arranged inside the main shaft, a pipe sleeve is arranged inside the fixed sleeve, the pipe sleeve is sleeved on the outside of the air pipe, a heating ring is arranged between the pipe sleeve and the fixed sleeve, and the heating ring is connected to the rotating end of the conductive slip ring through an electric wire.

[0026] A processing method of an ultrasonic-laser collaborative assisted milling system, characterized in that it comprises the following steps:

[0027] Step S1, fixing the workpiece to be processed to the workbench by a workpiece fixture;

[0028] Step S2, workpiece position calibration;

[0029] Step S3, starting the ultrasonic elliptical vibration unit and the laser emission module, the ultrasonic elliptical vibration unit generates ultrasonic elliptical vibration to act on the milling cutter;

[0030] The laser emission module generates a continuous laser beam, which passes through the beam hole and directly acts on the workpiece through the milling cutter head;

[0031] Step S4, the milling cutter performs milling operation on the workpiece according to a preset program;

[0032] In step S4, gas is taken in through the gas source device, and the gas passes through the gas rotary joint, the gas pipe and the gas hole in sequence and is blown out from the beam hole to blow out the waste chips entering the beam hole, so as to ensure that the continuous laser beam acts on the workpiece smoothly;

[0033] A heating structure is arranged in the main shaft, and the gas in the gas pipe is cooled by the heating structure;

[0034] The gas blown out of the beam hole is heated to prevent the low-temperature gas from cooling the processing surface of the workpiece.

[0035] The present invention provides an ultrasonic-laser collaborative assisted milling system and a processing method thereof. By adopting the above scheme, the following beneficial effects are achieved:

[0036] 1. Through ultrasonic-laser collaborative assisted milling, the dual advantages of ultrasonic vibration assisted processing and laser assisted processing are integrated, which can effectively improve the tool life of hard and brittle difficult-to-process materials and the processing surface quality of hard and brittle materials. It has a compact structure and is suitable for a variety of working environments.

[0037] 2. The continuous laser beam is transmitted directly through the central beam hole and acts on the workpiece processing surface by the milling cutter head, so that the continuous laser beam can be concentrated on the curved surface, deep cavity and groove structure. The purpose of laser-assisted processing can be fully achieved, ensuring the quality of milling processing.

[0038] 3. The air blowing method can not only blow away the waste chips generated by milling to ensure the milling quality, but also prevent the waste chips from blocking the beam hole, ensuring that the purpose of laser-assisted processing can be fully achieved.

[0039] 4. The blown airflow is heated and the temperature is adjusted as needed, which not only prevents the gas from cooling the workpiece surface, but also ensures the temperature of laser-assisted heating, thereby ensuring the effect of laser assistance and improving the quality of milling processing.

[0040] 5. When the laser-assisted heating temperature is too high, the gas blown out is used to cool it down to ensure the best milling conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0042] Figure 1 is a schematic diagram of the machining process of the ultrasonic-laser collaborative assisted milling system in an embodiment of the present invention;

[0043] Figure 2 is a schematic structural diagram of an ultrasonic-laser collaborative assisted milling system in an embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of ultrasonic-laser collaborative assisted milling of a complex curved surface structure in an embodiment of the present invention;

[0045] Figure 4 is a schematic diagram of ultrasonic-laser collaborative assisted milling of a deep cavity structure in an embodiment of the present invention;

[0046] Figure 5 is a schematic structural diagram of an ultrasonic-laser collaborative assisted milling system in an embodiment of the present invention;

[0047] Figure 6 It is a partially enlarged structural schematic diagram of the ultrasonic-laser collaborative assisted milling system in an embodiment of the present invention;

[0048] Figure 7 It is a partially enlarged structural schematic diagram of the ultrasonic-laser collaborative assisted milling system in an embodiment of the present invention;

[0049] Figure 8 It is an enlarged schematic diagram of the structure of the heating ring of the present invention.

[0050] In the figure:

[0051] Spindle 1, mechanical fixture 2, laser emission module 3, optical fiber slip ring 31, continuous laser beam 4, beam hole 41, optical fiber 5, laser control power supply 6, pre-tightening bolt 7, rear cover 8, first piezoelectric ceramic 9, copper electrode 10, middle cover 11, second piezoelectric ceramic 12, amplitude rod 13, fixing flange 14, tool handle 15, fixing ring 16, first ferrite coil 17, mounting frame 18, rotating ring 19, second ferrite coil 20, spring chuck 21, pressure Cap 22, milling cutter 23, workpiece 24, workpiece fixture 25, workbench 26, cable 27, dual-channel ultrasonic power supply 28, spindle housing 101, driven gear 102, driving gear 103, input shaft 104, gas rotary joint 201, air pipe connecting seat 202, air pipe 203, air hole 204, connecting frame 301, conduit 302, through hole 303, fixing sleeve 401, heating ring 402, pipe sleeve 403, conductive slip ring 404, wire 405. DETAILED DESCRIPTION

[0052] Embodiment 1:

[0053] like Figure 1 , Figure 2 and Figure 5 As shown, an ultrasonic-laser collaborative assisted milling system comprises a spindle 1 with a laser emission module 3, a tool handle 15 is provided at the end of the spindle 1, an ultrasonic elliptical vibration unit is provided in the tool handle 15, a milling cutter 23 is provided at the output end of the ultrasonic elliptical vibration unit, and beam holes 41 are provided in the spindle 1, the tool handle 15, the ultrasonic elliptical vibration unit and the milling cutter 23. The beam holes 41 are coaxial, and the concentricity deviation of the multiple beam holes 41 and the laser emission module 3 is less than 0.05 mm;

[0054] The ultrasonic elliptical vibration unit generates ultrasonic elliptical vibration to act on the milling cutter 23, and the laser emitting module 3 generates a continuous laser beam 4 which passes through the beam hole 41 and is emitted from the head of the milling cutter 23, so that the auxiliary milling cutter 23 realizes ultrasonic-laser collaborative assisted milling processing, which combines the dual advantages of ultrasonic vibration assisted processing and laser assisted processing, and can effectively improve the tool life and processing surface quality of hard, brittle and difficult-to-process materials. The continuous laser beam 4 is emitted through the head of the milling cutter 23 and can directly act on the processing surface of the workpiece 24 being processed, so that the continuous laser beam 4 can be concentrated in structures such as curved surfaces, deep cavities and grooves, so that the purpose of laser assisted processing can be fully achieved, thereby ensuring the processing quality, and the ultrasonic elliptical vibration directly acts on the milling cutter 23, ensuring the full realization of ultrasonic vibration assisted processing.

[0055] In a preferred embodiment, the laser emission module 3 is connected to the inside of the main shaft 1 through a mechanical fixing device 2, and a fiber slip ring 31 is provided at the end of the laser emission module 3. The output end of the fiber slip ring 31 is electrically connected to the laser emission module 3, and the output end of the fiber slip ring 31 is a rotating end. The input end of the fiber slip ring 31 is connected to a laser control power supply 6 through an optical fiber 5. The optical fiber 5 passes through the end of the main shaft 1, and the input end of the fiber slip ring 31 is a fixed end. The laser emission module 3 preferably emits a continuous laser beam 4 with an output power of 1 to 100 W, a wavelength of 1080 nm, and a spot diameter of 100 μm. When working, the output end of the fiber slip ring 31 rotates with the main shaft 1 and the laser emission module 3, and the input end of the fiber slip ring 31, the optical fiber 5 and the laser control power supply 6 do not rotate with it. The laser emission module 3 is controlled by the laser control power supply 6, and the specific power of the output continuous laser beam 4 depends on the actual processing situation and the material of the workpiece 24 to be processed.

[0056] The focal length of the continuous laser beam 4 output by the laser emission module 3 is set to the sum of the extension lengths of the tool handle 15, the ultrasonic vibration unit and the milling cutter 23, ensuring that the continuous laser beam can be accurately focused on the workpiece surface during the ultrasonic-laser collaborative assisted milling process. In this embodiment, the focal length of the laser emission module is 285 mm.

[0057] In the preferred embodiment, the ultrasonic elliptical vibration unit includes a fixed flange 14 connected to the end of the shank 15, and a variable amplitude rod 13 is provided inside the shank 15. The variable amplitude rod 13 passes through the fixed flange 14 and extends to the outside of the shank 15. The head of the variable amplitude rod 13 is connected to a spring chuck 21, and the external thread of the spring chuck 21 is connected to a pressure cap 22. The tail end of the milling cutter 23 is located inside the spring chuck 21. After loosening the pressure cap 22, the spring chuck 21 no longer clamps the milling cutter 23, and then the milling cutter 23 can be removed, and vice versa, it can be installed. The operation is simple and the milling cutter 23 can be easily disassembled and assembled.

[0058] The tail of the amplitude transformer 13 is provided with two second piezoelectric ceramics 12, a middle cover plate 11, two first piezoelectric ceramics 9, a rear cover plate 8 and a pre-tightening bolt 7 in sequence. The two second piezoelectric ceramics 12 and the two first piezoelectric ceramics 9 are connected with a copper electrode 10. The second piezoelectric ceramics 12 and the first piezoelectric ceramics 9 are both of PZT-4 type, and both work based on the high-efficiency d33 working mode of piezoelectric ceramics. The copper electrode 10 fits the second piezoelectric ceramics 12 and the first piezoelectric ceramics 9. The pre-tightening bolt 7 passes through the second piezoelectric ceramics 12, the middle cover plate 11, the copper electrode 10, the first piezoelectric ceramics 9 and the rear cover plate 8 and is threadedly connected to the amplitude transformer 13.

[0059] The copper electrode 10 is electrically connected to a dual-channel ultrasonic power supply 28 via a wireless power transfer unit.

[0060] The dual-channel ultrasonic power supply 28 is independently placed in the machining center and connected to the wireless power transmission unit via a cable 27 .

[0061] In the preferred scheme, the first piezoelectric ceramic 9 adopts axial polarization to excite the longitudinal vibration mode of the ultrasonic elliptical vibration unit; the second piezoelectric ceramic 12 adopts tangential polarization to excite the torsional vibration mode of the ultrasonic elliptical vibration unit, thereby realizing the longitudinal-torsional composite vibration mode of the ultrasonic elliptical vibration unit. The longitudinal-torsional composite vibration mode acts on the milling cutter 23, and the milling cutter 23 completes ultrasonic elliptical vibration milling.

[0062] In a preferred embodiment, the wireless power transmission unit includes a rotating ring 19 installed on the outside of the tool handle 15 using a heat-mounting technology, a second ferrite coil 20 electrically connected to the copper electrode 10 is encapsulated on the rotating ring 19 by epoxy resin glue, a dual-channel ultrasonic power supply 28 is electrically connected to the first ferrite coil 17 through a cable 27, the first ferrite coil 17 is encapsulated on the fixed ring 16 by epoxy resin glue, the first ferrite coil 17 is electrically connected to the second ferrite coil 20 in a contact manner, and the fixed ring 16 is connected to the spindle housing 101 through a mounting bracket 18. During the rotation of the spindle 1, the rotating ring 19 and the second ferrite coil 20 rotate with it, the fixed ring 16 and the first ferrite coil 17 are connected to the spindle housing 101 and cannot rotate, and the first ferrite coil 17 is electrically connected to the second ferrite coil 20 in a contact manner, so that the transmission of the ultrasonic signal is not affected during the rotation, thereby ensuring that the first ferrite coil 17 and the second ferrite coil 20 can normally receive the excitation of the ultrasonic signal;

[0063] The two-phase excitation signals of the dual-channel ultrasonic power supply 28 respectively excite the first ferrite coil 17 and the second ferrite coil 20. By independently adjusting the voltage value and phase difference of the two-phase excitation signals of the dual-channel ultrasonic power supply 28, precise control of the longitudinal vibration, torsional vibration and phase difference can be achieved, thereby achieving precise control of the ultrasonic elliptical vibration trajectory output by the tip of the milling cutter 23.

[0064] To ensure the efficiency and stability of the induction and transmission of electric energy, a gap of 1 mm should be maintained between the fixed ring 16 and the rotating ring 19 of the wireless power output unit.

[0065] In the preferred embodiment, Figure 5 and Figure 7 As shown, the main shaft 1 is rotatably connected to the main shaft housing 101 through a bearing, a driven gear 102 is connected to the outer shell of the main shaft 1, an input shaft 104 is rotatably arranged in the main shaft housing 101, a driving gear 103 is fixed to the end of the input shaft 104, and the driving gear 103 is meshed with the driven gear 102;

[0066] The input shaft 104 is the output shaft of a milling device or a machining center, or the output shaft of the milling device is connected through the input shaft 104 and a coupling. The connection is simple and can adapt to different output shafts of machining centers.

[0067] The milling equipment uses the existing technology to output rotational motion to drive the input shaft 104 to rotate, thereby driving the driving gear 103, the driven gear 102 and the main shaft 1 to rotate in turn, and then driving the tool handle 15 and the milling cutter 23 to complete the milling work.

[0068] The milling cutter 23 is made of ultrafine powder cemented carbide material, which not only has excellent processing performance, but also is more conducive to the transmission of ultrasonic vibration and energy loss. In this embodiment, the milling cutter has a diameter of 8 mm, four cutting edges, a helix angle of 60°, and a cutting edge rake angle of 5°.

[0069] Embodiment 2:

[0070] like Figure 5 , Figure 6 and Figure 7 As shown, a gas rotary joint 201 is provided at the end of the main shaft 1, and the input end of the gas rotary joint 201 is connected to an external gas source device, and the input end of the gas rotary joint 201 is a fixed end. When the main shaft 1 rotates, the input end of the gas rotary joint 201 does not rotate accordingly;

[0071] The output end of the gas rotary joint 201 is connected to the gas pipe 203, and the output end of the gas rotary joint 201 is a rotating end. When the main shaft 1 rotates, the output end of the gas rotary joint 201 rotates accordingly. The inner wall of the main shaft 1 is provided with a gas pipe connecting seat 202. The gas pipe 203 is located inside the main shaft 1, and one end of the gas pipe 203 away from the gas rotary joint 201 is connected to the gas pipe connecting seat 202.

[0072] An air hole 204 is provided inside the spindle 1, one end of the air hole 204 is connected to the air pipe connection seat 202, and the other end of the air hole 204 is connected to the light beam hole 41, and the air hole 204 can be extended into the handle 15;

[0073] The gas hole 204 is arranged obliquely to ensure that the gas is output downward into the beam hole 41 .

[0074] During the milling process, the air flow generated by the gas source equipment in the prior art is sent to the input end of the gas rotary joint 201 through a pipeline, and then passes through the output end of the gas rotary joint 201, the air pipe 203 and the air hole 204 in sequence, and is blown out through the beam hole 41. This can not only blow away the waste chips generated by milling to ensure the quality of the milling process, but also prevent the waste chips from blocking the beam hole 41, thereby ensuring that the continuous laser beam 4 can act on the workpiece 24, that is, ensuring the full realization of laser assistance.

[0075] In the preferred solution, a through hole is provided at the center of the gas rotary joint 201, the fixed end of the optical fiber slip ring 31 is connected to the connecting frame 301, the connecting frame 301 is connected to the conduit 302, the conduit 302 is hollow, the conduit 302 passes through the through hole, the conduit 302 is connected to the fixed end of the gas rotary joint 201, and the optical fiber 5 passes through the conduit 302 and the connecting frame 301 and is connected to the optical fiber slip ring 31. The conduit 302 can ensure that the optical fiber 5 and other lines enter the main shaft 1 normally, thereby ensuring the stability of the work and preventing the fixed end of the optical fiber slip ring 31 and the optical fiber 5 from rotating with the main shaft 1.

[0076] Embodiment 3:

[0077] like Figure 5 , Figure 7 and Figure 8 As shown, in the preferred solution, a heating mechanism is provided at the air pipe 203, and the heating mechanism includes a conductive slip ring 404 provided on the outside of the conduit 302, and the fixed end of the conductive slip ring 404 is connected to the connecting frame 301. The external circuit of the conductive slip ring 404 passes through the conduit 302 and is externally connected to the power supply device and the control device. The conductive slip ring 404 is an existing conductive slip ring with a hollow hole, and the hollow hole is used for the conduit 302 to pass through. A through hole 303 is provided in the connecting frame 301, and the through hole 303 is a spare hole. The circuit chooses whether to pass through the through hole 303 according to the actual connection situation;

[0078] A fixed sleeve 401 is provided inside the spindle 1, and a pipe sleeve 403 is provided inside the fixed sleeve 401. The pipe sleeve 403 is sleeved on the outside of the air pipe 203. A heating ring 402 is provided between the pipe sleeve 403 and the fixed sleeve 401. The heating ring 402 is connected to the rotating end of the conductive slip ring 404 through an electric wire 405. The heating ring 402 is preferably an electric heating ring or a cast aluminum heating ring. The heating temperature is controlled at 20°~X, where X is the melting point temperature of the air pipe 203 -10°, which is determined according to the actual processing conditions and the material of the workpiece 24 being processed.

[0079] During the milling process, the adverse effects of milling waste are reduced by blowing air, and the blown gas is heated to prevent the gas from cooling the processing surface of the workpiece 24, thereby ensuring the temperature of laser-assisted heating, and then ensuring the effect of laser assistance, and the quality of milling processing is better; and when the laser-assisted heating temperature is too high, the gas can be cooled by blowing the gas instead of heating, to ensure the best milling conditions and the quality of milling processing is better.

[0080] Embodiment 4:

[0081] A processing method of an ultrasonic-laser collaborative assisted milling system, characterized in that it comprises the following steps:

[0082] Step S1, fixing the workpiece 24 to be processed to the workbench 26 through the workpiece fixture 25;

[0083] Step S2, calibrating the position of the workpiece 24;

[0084] Step S3, starting the ultrasonic elliptical vibration unit and the laser emission module 3, the ultrasonic elliptical vibration unit generates ultrasonic elliptical vibration to act on the milling cutter 23;

[0085] The laser emitting module 3 generates a continuous laser beam 4, which passes through the beam hole 41 and directly acts on the workpiece 24 through the head of the milling cutter 23;

[0086] Step S4, the milling cutter 23 performs a milling operation on the workpiece 24 according to a preset program;

[0087] In step S4, gas is taken in through the gas source device, and the gas passes through the gas rotary joint 201, the gas pipe 203 and the gas hole 204 in sequence and then blown out from the beam hole 41 to blow out the waste chips entering the beam hole 41, so as to ensure that the continuous laser beam 4 acts smoothly on the workpiece 24;

[0088] The gas blown out of the beam hole 41 is heated to prevent the low-temperature gas from cooling the processing surface of the workpiece 24 .

[0089] The spot shape formed by the continuous laser beam after focusing on the surface of the workpiece 24 is circular, and the spot diameter is 2 mm. The temperature field formed by the laser spot at the focusing position on the surface of the workpiece 24 is Gaussian distributed, and the temperature field of the processing area can be precisely controlled by adjusting the power of the continuous laser beam 4, thereby effectively preventing the material from being burned while softening the hard and brittle materials and improving the material additivity.

[0090] The output path of the tip of the milling cutter 23 is an elliptical vibration trajectory composed of longitudinal ultrasonic vibration and torsional ultrasonic vibration. It can not only realize the periodic separation of the milling cutter 23 and the workpiece 24, so that the heat in the cutting zone can be effectively extracted, but also significantly improve the relative speed of the milling cutter 23, as shown in the following formula (1), thereby increasing the strain rate in the cutting zone, improving the plastic flow of hard and brittle materials, and being beneficial to reducing tool wear and generating high-precision surfaces.

[0091] (1);

[0092] Among them, V X (t) is the longitudinal ultrasonic vibration velocity, V Z (t) is the torsional ultrasonic vibration velocity, f is the vibration frequency of the blade tip, t is the time, V f is the relative cutting speed, A X and A Z are the amplitudes in the X and Z directions, respectively, and Δφ is the phase difference between the two-phase ultrasonic vibrations. In this embodiment, the X direction is the cutting depth direction, the Z direction is the cutting speed direction, and A X 3μm, AZ is 9μm and Δφ is 60°.

[0093] The workpiece 24 is mounted on a workbench 26 of a machining center through a workpiece fixture 25 .

[0094] like Figure 3 The deep cavity structure processing of hard and brittle materials shown in Figure 4 For the processing of complex curved surface structures of hard and brittle materials, the milling system of the present invention can realize the synchronous output of ultrasonic elliptical vibration and continuous laser beam 4 on the milling cutter 23 while the milling cutter 23 performs rotational milling motion, so as to perform ultrasonic-laser collaborative assisted milling, enhance the plastic flow of materials, reduce the wear of the tool, and realize the precision processing of deep cavity structures of hard and brittle materials. It breaks through the technical bottleneck of the existing external and oblique laser assisted heating method that cannot be focused on the milling position due to interference and cannot be applied to complex structures such as curved surfaces, deep cavities and groove processing, and ensures that ultrasonic vibration assistance and laser assistance can be fully realized.

[0095] At the same time, during the milling process, air flow is continuously blown out from the beam hole 41 , which can not only blow away the waste chips generated by milling to ensure the quality of the milling process, but also prevent the waste chips from blocking the beam hole 41 , ensuring that the continuous laser beam 4 can act on the workpiece 24 .

[0096] Furthermore, the airflow blown out of the beam hole 41 is heated, which can prevent the airflow from cooling the processing surface of the workpiece 24, thereby ensuring the milling effect.

[0097] The workpiece 24 of the present application includes but is not limited to a hard and brittle material workpiece and a complex structure workpiece.

Claims

1. An ultrasonic-laser collaborative assisted milling system, characterized by: It comprises a main shaft (1) having a laser emission module (3) therein, a tool handle (15) being provided at the end of the main shaft (1), an ultrasonic elliptical vibration unit being provided in the tool handle (15), a milling cutter (23) being provided at the output end of the ultrasonic elliptical vibration unit, and beam holes (41) being provided in the main shaft (1), the tool handle (15), the ultrasonic elliptical vibration unit and the milling cutter (23), and the beam holes (41) are coaxial; The ultrasonic elliptical vibration unit generates ultrasonic elliptical vibration to act on the milling cutter (23), and the laser emission module (3) generates a continuous laser beam (4) which passes through the beam hole (41) and is then emitted from the head of the milling cutter (23), thereby assisting the milling cutter (23) to achieve ultrasonic-laser collaborative assisted milling processing; The light beam hole (41) is connected to an air pipe (203) for air intake. The air pipe (203) is provided with a heating mechanism for heating the air entering the air pipe (203) so that the air entering the light beam hole (41) is hot air for blowing away waste chips and controlling the temperature. The heating mechanism comprises a fixed sleeve (401) disposed inside the main shaft (1), a pipe sleeve (403) being disposed inside the fixed sleeve (401), the pipe sleeve (403) being sleeved on the outside of the air pipe (203), and a heating ring (402) being disposed between the pipe sleeve (403) and the fixed sleeve (401); The laser emission module (3) is connected to the interior of the main shaft (1) via a mechanical fixing device (2); an optical fiber slip ring (31) is provided at the end of the laser emission module (3); the output end of the optical fiber slip ring (31) is electrically connected to the laser emission module (3); the output end of the optical fiber slip ring (31) is a rotating end; the input end of the optical fiber slip ring (31) is connected to a laser control power supply (6) via an optical fiber (5); the optical fiber (5) passes through the end of the main shaft (1); and the input end of the optical fiber slip ring (31) is a fixed end; A gas rotary joint (201) is provided at the end of the main shaft (1), an input end of the gas rotary joint (201) is connected to an external gas source device, and the input end of the gas rotary joint (201) is a fixed end; The output end of the gas rotary joint (201) is connected to a gas pipe (203), and the output end of the gas rotary joint (201) is a rotating end. The inner wall of the main shaft (1) is provided with a gas pipe connecting seat (202). The gas pipe (203) is located inside the main shaft (1), and one end of the gas pipe (203) away from the gas rotary joint (201) is connected to the gas pipe connecting seat (202). An air hole (204) is provided inside the main shaft (1), one end of the air hole (204) is communicated with the air pipe connecting seat (202), and the other end of the air hole (204) is communicated with the light beam hole (41); The air hole (204) is arranged obliquely.

2. The ultrasonic-laser collaborative assisted milling system according to claim 1, characterized in that: The ultrasonic elliptical vibration unit comprises a fixed flange (14) connected to the end of a tool handle (15); a variable amplitude rod (13) is provided inside the tool handle (15); the variable amplitude rod (13) passes through the fixed flange (14) and extends to the outside of the tool handle (15); a spring chuck (21) is connected to the head of the variable amplitude rod (13); a pressure cap (22) is threadedly connected to the outside of the spring chuck (21); and the tail end of the milling cutter (23) is located inside the spring chuck (21); The tail of the amplitude transformer (13) is provided with two second piezoelectric ceramics (12), a middle cover plate (11), two first piezoelectric ceramics (9), a rear cover plate (8) and a pre-tightening bolt (7) in sequence; the two second piezoelectric ceramics (12) and the two first piezoelectric ceramics (9) are both connected with a copper electrode (10); the copper electrode (10) fits the second piezoelectric ceramics (12) and the first piezoelectric ceramics (9); the pre-tightening bolt (7) passes through the second piezoelectric ceramics (12), the middle cover plate (11), the copper electrode (10), the first piezoelectric ceramics (9) and the rear cover plate (8) and is then threadedly connected to the amplitude transformer (13); The copper electrode (10) is electrically connected to a dual-channel ultrasonic power supply (28) via a wireless power transfer unit.

3. The ultrasonic-laser collaborative assisted milling system according to claim 2 is characterized in that: The wireless power transmission unit comprises a rotating ring (19) sleeved on the outside of the tool handle (15), a second ferrite coil (20) electrically connected to the copper electrode (10) is provided on the rotating ring (19), a dual-channel ultrasonic power supply (28) is electrically connected to the first ferrite coil (17) via a cable (27), the first ferrite coil (17) is provided on the fixed ring (16), the first ferrite coil (17) is electrically connected to the second ferrite coil (20) in a contact manner, and the fixed ring (16) is connected to the spindle housing (101) via a mounting frame (18).

4. The ultrasonic-laser collaborative assisted milling system according to claim 2, characterized in that: The first piezoelectric ceramic (9) adopts axial polarization to excite the longitudinal vibration mode of the ultrasonic elliptical vibration unit; the second piezoelectric ceramic (12) adopts tangential polarization to excite the torsional vibration mode of the ultrasonic elliptical vibration unit, thereby realizing the longitudinal-torsion composite vibration mode of the ultrasonic elliptical vibration unit.

5. The ultrasonic-laser collaborative assisted milling system according to claim 1, characterized in that: The main shaft (1) is rotatably connected to the main shaft housing (101) via a bearing, a driven gear (102) is connected to the outer shell of the main shaft (1), an input shaft (104) is rotatably arranged in the main shaft housing (101), a driving gear (103) is fixed to the end of the input shaft (104), and the driving gear (103) is meshed with the driven gear (102); The input shaft (104) is the output shaft of the milling device.

6. The ultrasonic-laser collaborative assisted milling system according to claim 1, characterized in that: A through hole is provided at the center of the gas rotary joint (201); a connecting frame (301) is connected to the fixed end of the optical fiber slip ring (31); the connecting frame (301) is connected to a conduit (302); the conduit (302) is hollow; the conduit (302) passes through the through hole; the conduit (302) is connected to the fixed end of the gas rotary joint (201); and the optical fiber (5) passes through the conduit (302) and the connecting frame (301) and is connected to the optical fiber slip ring (31).

7. The ultrasonic-laser collaborative assisted milling system according to claim 6, characterized in that: A through hole (303) is provided in the connecting frame (301); The heating mechanism further comprises a conductive slip ring (404) provided outside the conduit (302); a fixed end of the conductive slip ring (404) is connected to the connecting frame (301); and an external connection line of the conductive slip ring (404) passes through the conduit (302) and is externally connected to a power supply device and a control device. The heating ring (402) is connected to the rotating end of the conductive slip ring (404) via an electric wire (405).

8. A processing method of the ultrasonic-laser collaborative assisted milling system according to any one of claims 1 to 7, characterized in that The steps include: Step S1, fixing the workpiece (24) to be processed to the workbench (26) by means of a workpiece fixture (25); Step S2, calibrating the position of the workpiece (24); Step S3, starting the ultrasonic elliptical vibration unit and the laser emission module (3), so that the ultrasonic elliptical vibration unit generates ultrasonic elliptical vibration to act on the milling cutter (23); The laser emission module (3) generates a continuous laser beam (4), and the continuous laser beam (4) passes through the beam hole (41) and then acts directly on the workpiece (24) through the head of the milling cutter (23); Step S4, the milling cutter (23) performs a milling operation on the workpiece (24) according to a preset program; In step S4, gas is introduced through the gas source device, and the gas passes through the gas rotary joint (201), the gas pipe (203) and the gas hole (204) in sequence before being blown out from the beam hole (41) to blow out waste chips entering the beam hole (41) and ensure that the continuous laser beam (4) acts smoothly on the workpiece (24); The gas blown out of the beam hole (41) is heated to prevent the low-temperature gas from cooling the processing surface of the workpiece (24).

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