Laser processing device for surface microstructure of thin-wall spherical shell type micro component

Abstract

The invention discloses a laser machining device for a surface microstructure of a thin-wall spherical shell type micro-component, and relates to the technical field of micro-component surface machining. The problem that due to the fact that traditional material removal modes such as ultra-precision cutting are incomplete in material removal and substandard in contour precision, the manufacturing requirement caused by the nanoscale precision of the surface microstructure of the thin-wall spherical shell micro-component cannot be met is solved, the device comprises an X / Y / Z / B / C axis movement unit, a Y axis, a B axis and a C axis are sequentially arranged on a horizontal base table board in a stacked mode, and a workpiece is installed on a C axis objective table; the X axis and the Z axis are mounted on a cross beam of the portal frame in an overlapping manner, the laser processing head is fixed on a Z-axis carriage, and the workpiece position change introduced by the swing of the B axis can be compensated through the X axis; according to the device, laser processing and in-situ detection of the surface microstructure of the thin-wall spherical shell micro-component are integrated, high-precision adjustment of a movement position, precise regulation and control of laser pulse energy and precise capturing and recognition of a feature point position can be achieved, and high-precision stable controllable removal of an incomplete part of a cutting processing material is met.

Description

Technical Field

[0001] This invention relates to the technical field of surface processing of micro-components, and more particularly to a laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components. Background Technology

[0002] With the rapid development of modern science and technology, various high-performance, multi-scale, integrated, and high-precision thin-walled spherical shell complex micro-components have been widely used in fields such as national defense, aerospace, biomedicine, and mechatronics. These parts typically have spherical diameters ranging from millimeters to sub-millimeters, and their surfaces are distributed with multiple multi-scale irregular features. Their machining accuracy requirements include nanometer-level surface roughness, sub-millimeter-level shape accuracy, and significant morphological consistency among the feature structures. Currently, relatively mature single-material removal methods such as electrical discharge machining (EDM) and ultra-precision cutting mainly address the manufacturing needs of macroscopic parts' surface contours and micro-morphologies. Limited by manufacturing principles and equipment errors, their manufacturing accuracy cannot meet the nanometer-level precision requirements for creating micro-component surface feature structures within confined spaces.

[0003] Under the constraints of micro-scale, the unique structural characteristics, material inhomogeneity, significant sphericity error, and minute surface defects of thin-walled spherical micro-components pose higher and more urgent demands on their surface microstructure processing equipment and manufacturing methods. Existing material processing methods, such as ultra-precision cutting, can remove surface features from micro-components; however, problems such as tool wear, chip accumulation, system chatter, weak rigidity deformation, and environmental fluctuations during processing lead to incomplete material removal, limiting further improvements in processing accuracy. Laser processing, as an emerging material processing method, has been widely applied in laser welding, laser drilling, and cutting. Compared to traditional processing methods, laser processing employs a non-contact material removal mode, offering strong anti-interference capabilities. The laser beam possesses excellent monochromaticity and directionality, making it easy to guide and focus. The processing method is flexible and easily integrated with multi-axis CNC systems, effectively avoiding surface scratches, cracks, and discoloration. Workpiece thermal deformation is minimal, and processing accuracy is higher, making it suitable for creating nanoscale precision surfaces of microstructures. To address the shortcomings of ultra-precision cutting technology, this paper proposes an ultra-precision laser processing method for fabricating microstructures on the surface of thin-walled spherical shell micro-components. This method aims to achieve high-precision removal of microstructures from the surface of micro-components, meeting practical engineering needs. Therefore, research and development of laser processing equipment and processing technology for fabricating thin-walled spherical shell microstructures is of great practical significance, addressing the urgent need for high-precision complex micro-components in various fields. Summary of the Invention

[0004] To address the problem that traditional material removal methods, such as ultra-precision cutting, cannot meet the manufacturing requirements for creating nanoscale precision microstructures on the surface of thin-walled spherical shell micro-components due to incomplete material removal and substandard contour accuracy, the present invention aims to provide a laser processing device for microstructures on the surface of thin-walled spherical shell micro-components.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A laser processing device for surface microstructures of thin-walled spherical shell micro-components includes: a gantry, a base 1, a B-axis motion unit 2, a Z-axis motion unit 3, an optical component 4, a laser 5, a beam transmission component 6, an X-axis motion unit 7, a detection head 8, a fixture 10, a zero-point quick-change system 11, a C-axis motion unit 12, and a Y-axis motion unit 13. The gantry is mounted on the upper surface of the base 1, and the Y-axis motion unit 13 is mounted in the middle of the upper surface of the base 1, located inside the gantry. The B-axis motion unit 2 is mounted on the slide of the Y-axis motion unit 13, and the Y-axis motion unit 13 is used to realize the forward and backward displacement movement of the B-axis motion unit 2 along the Y-axis. The C-axis motion unit 12 is mounted on the rotary table of the B-axis motion unit 2, and the B-axis motion unit 2 is used to realize the rotational movement of the C-axis motion unit 12 around the B-axis. The zero-point quick-change system 11 is mounted on the C-axis motion unit 13. On the rotary table of unit 12, a clamp 10 is mounted on a zero-point quick-change system 11. The clamp 10 is used to clamp the thin-walled spherical shell micro-component 9. The C-axis motion unit 12 is used to realize the rotational motion of the thin-walled spherical shell micro-component 9 around the C-axis. The X-axis motion unit 7 is mounted on the gantry, and the Z-axis motion unit 3 is mounted on the slide of the X-axis motion unit 7. The X-axis motion unit 7 is used to realize the displacement motion of the Z-axis motion unit 3 along the X-axis. The optical component 4 and the detection head 8 are both mounted on the slide of the Z-axis motion unit 3. The Z-axis motion unit 3 is used to realize the displacement motion of the optical component 4 and the detection head 8 along the Z-axis. The laser 5 and the beam transmission component 6 are both mounted on the top of the gantry. The laser 5 transmits the laser to the optical component 4 through the beam transmission component 6. The optical component 4 is used for laser processing of the surface of the thin-walled spherical shell micro-component 9 and optical microscopic imaging of the processing position.

[0007] In the aforementioned laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components, the B-axis is parallel to the Y-axis.

[0008] In the aforementioned laser processing device for surface microstructures of thin-walled spherical shell micro-components, the C-axis is parallel to the Z-axis.

[0009] The laser processing device for the surface microstructure of the thin-walled spherical shell micro-component mentioned above includes a gantry frame comprising: lateral vertical beams and a top horizontal beam. The lower ends of the two lateral vertical beams are connected to the upper surface of the base 1, and the left and right ends of the top horizontal beam are connected to the upper ends of the two lateral vertical beams, respectively. The Y-axis motion unit 13 is located between the two lateral vertical beams.

[0010] The aforementioned laser processing device for the surface microstructure of thin-walled spherical shell micro-components includes a beam transmission component 6 comprising a shutter 14, a beam polarization state adjustment unit, a beam expander 17, and a spatial filtering system 18. The beam polarization state adjustment unit comprises a half-wave plate 15 and a glaring lens 16. The laser 5, shutter 14, half-wave plate 15, glaring lens 16, and beam expander 17 are arranged sequentially along the axial direction. The laser beam emitted from the laser 5 passes through the shutter 14, half-wave plate 15, glaring lens 16, and beam expander 17 in sequence before being emitted. The beam polarization state adjustment unit is used to change the polarization state of the emitted laser beam, and the beam expander 17 is used to expand the laser beam.

[0011] The laser processing device for the surface microstructure of the thin-walled spherical shell micro-components described above, wherein the beam transmission component 6 further includes: a spatial filtering system 18, through which the laser beam expanded by the beam expander 17 passes.

[0012] The laser processing device for the surface microstructure of the thin-walled spherical shell micro-components described above, wherein the beam transmission component 6 further includes: a beam quality analyzer 19 and a beam splitter 20. The laser beam passing through the spatial filtering system 18 passes through the beam splitter 20, and the laser beam reflected by the beam splitter 20 enters the beam quality analyzer 19. The beam quality analyzer 19 is used to monitor and analyze the quality of the laser beam in real time.

[0013] The laser processing device for the surface microstructure of the thin-walled spherical shell micro-component described above, wherein the beam transmission component 6 further includes: a second beam splitter 21 and a laser power meter 22. The laser beam transmitted through the first beam splitter 20 passes through the second beam splitter 21, and the laser beam reflected by the second beam splitter 21 enters the laser power meter 22. The laser power meter 22 is used to monitor the laser beam power in real time.

[0014] The aforementioned laser processing device for the surface microstructure of thin-walled spherical shell micro-components includes an optical component 4 comprising: a dichroic mirror 23, a processing objective lens 24, a beam splitter 25, an imaging objective lens 26, a CCD camera 27, and a coaxial microscopic imaging illumination source 28. The CCD camera 27, imaging objective lens 26, dichroic mirror 25, beam splitter 25, and processing objective lens 24 are arranged sequentially along the axial direction. The laser beam transmitted through the beam splitter 21 passes through the dichroic mirror 23, and the laser beam reflected by the dichroic mirror 23 passes through the processing objective lens 24 to perform laser processing on the thin-walled spherical shell micro-component 9. The coaxial microscopic imaging illumination source 28 is located on the side of the beam splitter 25. The beam splitter 25, imaging objective lens 26, CCD camera 27, and coaxial microscopic imaging illumination source 28 constitute a coaxial microscopic imaging system.

[0015] The laser processing device for the surface microstructure of the thin-walled spherical shell micro-components described above includes B-axis motion unit 2 and C-axis motion unit 12, which are both precision direct-drive rotary tables; X-axis motion unit 7 and Y-axis motion unit 13, which are both precision direct-drive platforms; and Z-axis motion unit 3, which is a nano-positioning stage.

[0016] The present invention, by employing the above-mentioned technology, has the following positive effects compared with the prior art:

[0017] (1) This invention utilizes the high spatial resolution of laser micromachining technology to improve the manufacturing spatial response capability, enhances manufacturing stability by the characteristic of no macroscopic force in laser processing, and improves manufacturing contour accuracy and surface quality through the photochemical interaction mechanism of ultraviolet laser and polymer material, thus meeting the manufacturing requirements of nanoscale surface roughness and sub-millimeter shape accuracy of multiple cross-scale irregular features on the surface of thin-walled spherical shells from millimeter to sub-millimeter scale.

[0018] (2) The present invention uses high-precision linear motion units and rotary motion units as the main moving parts. The positioning accuracy of the X / Y / Z axis linear motion unit is better than 0.5μm, the bidirectional repeatability positioning is better than 0.3μm, and the straightness is better than 1.5μm; the positioning accuracy of the B / C axis rotary motion unit is better than 5", the bidirectional repeatability positioning is better than 3", and the axial error is better than 2μm. It meets the high-precision control requirements for the precise calibration of the laser beam focal position and the relative position of the feature structure and the laser beam, and is suitable for high-precision laser processing of complex micro-components such as thin-walled spherical shells under the constraint of narrow space.

[0019] (3) This invention integrates laser processing of surface microstructures of thin-walled spherical shell micro-components with in-situ detection, and can realize functions such as high-precision adjustment of motion position, precise control of laser pulse energy, and accurate identification of feature points, so as to meet the high-precision, stable and controllable removal of incomplete parts of cutting materials.

[0020] (4) In this invention, the base is made of granite material, which has a small coefficient of thermal expansion, can absorb vibration well, eliminate processing errors caused by thermal expansion, and has a good vibration isolation effect. Therefore, it can greatly improve the performance of the device and is suitable for high-precision creation of precision / ultra-precision microstructures.

[0021] (5) The present invention has a certain degree of universality. It is not only applicable to the high-precision laser processing and manufacturing of surface feature structures of thin-walled spherical shell micro-components, but can also be further promoted to the specific practice of high-precision laser creation of complex configuration parts such as micro-steps, micro-arrays, and free-form surfaces. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a laser processing device for surface microstructures of thin-walled spherical shell micro-components according to the present invention.

[0023] Figure 2 This is a schematic diagram of the optical path of a laser processing device for surface microstructures of thin-walled spherical shell micro-components according to the present invention.

[0024] In the attached diagram: 1. Base; 2. B-axis motion unit; 3. Z-axis motion unit; 4. Optical assembly; 5. Laser; 6. Beam transmission component; 7. X-axis motion unit; 8. Detection head; 9. Thin-walled spherical shell micro-component; 10. Fixture; 11. Zero-point quick-change system; 12. C-axis motion unit; 13. Y-axis motion unit; 14. Shutter; 15. Half-wave plate; 16. Granlin mirror; 17. Beam expander; 18. Spatial filtering system; 19. Beam quality analyzer; 20. Beam splitter one; 21. Beam splitter two; 22. Laser power meter; 23. Dichroic mirror; 24. Processing objective; 25. Beam splitter three; 26. Imaging objective; 27. CCD camera; 28. Coaxial microscopic imaging illumination source. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0026] Please refer to Figure 1 and Figure 2As shown in Figure 1, a laser processing device for the surface microstructure of thin-walled spherical shell micro-components is illustrated. It mainly consists of a base 1, a Y-axis motion unit 13, a B-axis motion unit 2, a C-axis motion unit 12, a zero-point quick-change system 11, a fixture 10, thin-walled spherical shell micro-components 9, a Z-axis motion unit 3, an X-axis motion unit 7, an optical assembly 4, a detection head 8, and a beam transmission component 6. The entire device adopts a gantry structure. The base 1 is a large platform made of granite, which effectively absorbs environmental vibrations to improve structural stability. The Y-axis linear motion unit 13 is driven by a linear motor and horizontally connected to the base 1 by screws, enabling high-precision reciprocating linear motion in the horizontal direction. The B-axis motion unit 2 is connected to the slide of the Y-axis linear motion unit 13 by drop screws, moving with the Y-axis and achieving high-precision rotary motion. The C-axis motion unit 12 is connected to the rotary table of the B-axis motion unit by screws via a ramp, rotating with the B-axis. The zero-point quick-change system 11 is connected to the C-axis motion unit 12 by screws and can rotate with the C-axis. The thin-walled spherical shell micro-component 9 is clamped onto the fixture 10 by negative pressure adsorption. The fixture 10 is connected to the reference plate of the zero-point quick-change system by screws and to the base of the zero-point quick-change system by pull studs. The X-axis motion unit 7 is connected to the vertical gantry by screws, and the Z-axis motion unit 3 is connected to the slide of the X-axis motion unit 7 by screws and can reciprocate with the X-axis motion unit. The laser focusing and optical microscopic imaging component 4 is connected to the slide of the Z-axis motion unit 3 by screws and can move with the Z-axis motion unit and the X-axis motion unit to achieve high-precision removal of microstructure materials. The detection head 8 is connected to the slide of the Z-axis motion unit 3 by screws and can move with the Z-axis motion unit and the X-axis motion unit to achieve precise calibration of the spatial position of the microstructure and the laser focus. The laser 5 is fixed to the top of the gantry by screws and transmits the laser to the laser focusing and optical microscopic imaging component 4 through the beam transmission and control component.

[0027] Furthermore, in a preferred embodiment, beam splitter 20 is a 10:90 beam splitter (ultraviolet band), beam splitter 21 is a 50:50 beam splitter (ultraviolet band), and beam splitter 25 is a 50:50 beam splitter (visible light band).

[0028] Furthermore, in a preferred embodiment, the optical system beam transmission component 6 mainly consists of a laser 5, a thin-walled spherical shell-like micro-component 9, a shutter 14, a half-wave plate 15, a Granlin mirror 16, a beam expander 17, a spatial filtering system 18, a beam quality analyzer 19, a 10:90 beam splitter (ultraviolet band), a 50:50 beam splitter (ultraviolet band), a laser power meter 22, a dichroic mirror (ultraviolet band) 23, a processing objective lens 24, a 50:50 beam splitter (visible light band), an imaging objective lens 26, a CCD camera 27, and a coaxial microscopic imaging illumination source 28, as shown in Figure 2. The shutter 14 is used to control the on / off state of laser transmission, and is normally closed during non-processing periods, with its status displayed on the control interface. A half-wave plate 15 and a Granlin mirror 16 form a beam polarization state adjustment unit to change the polarization state of the emitted laser beam, thereby obtaining high-quality linearly polarized light and improving laser processing accuracy and quality. A beam expander 17 expands the laser beam to obtain a central portion with better beam quality. A spatial filtering system 18 shapes the spatial Gaussian distribution of the laser beam's energy, filtering out clutter components other than the central Gaussian distribution. A 10:90 beam splitter (ultraviolet band) extracts a portion of the beam from the optical path, and a beam quality analyzer 1... 9. The quality of the laser beam is monitored and analyzed in real time. A 50:50 beam splitter (ultraviolet band) extracts part of the beam, and a laser power meter 22 monitors the laser power in real time. A dichroic mirror (ultraviolet band) 23 reflects the laser beam into the processing objective lens 24. The focused laser beam acts on the surface of the thin-walled spherical micro-component 9 for microstructure processing. A 50:50 beam splitter (visible light band), a coaxial microscopic imaging illumination source 28, an imaging objective lens 26, and a CCD camera 27 form a coaxial microscopic imaging system used for initial positioning of the processing location.

[0029] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention.

[0030] In addition to the above, the present invention also has the following embodiments:

[0031] In a further embodiment of the present invention, the working principle and operation method are as follows: A laser device for manufacturing microstructures on the surface of thin-walled spherical shell micro-components mainly consists of a motion system, an optical system, an in-situ detection system, and an auxiliary system. The motion system includes X-axis, Y-axis, Z-axis, B-axis, and C-axis motion units. The X / Y-axis linear motion unit adopts a precision direct-drive platform, and the Z-axis linear motion unit uses a nano-positioning stage, both driven by ironless linear motors and with real-time feedback of motion position from an open linear grating system. The B / C-axis rotary motion unit adopts a precision direct-drive turntable, driven by a split-type ironless torque motor and with real-time feedback of pose information from a tube grating, enabling five-axis four-linkage to precisely adjust the positional relationship between each feature structure on the surface of the thin-walled spherical shell microstructure and the laser beam, so that the laser beam focus falls on the surface of the feature structure to be processed. The optical system includes two parts: a beam transmission and control subsystem and a laser focusing and optical coaxial microscopic imaging subsystem, used to adjust the laser emitted by the laser into a pulse beam with a specified intensity and spatial distribution, and transmit and focus it onto the processing position. The beam transmission and control subsystem consists of an optical shutter, polarization adjustment unit, beam expander unit, detection unit, spatial filtering system, focusing processing objective lens, and reflectors and detection probes required for beam transmission and detection. The laser focusing and optical microscopy imaging subsystem is coaxial and confocal with the focused beam, providing a focused beam that meets process requirements for laser manufacturing. It also provides clear imaging of characteristic microstructures to identify their contours and determine the position of the focused spot within the field of view, further establishing the initial relative position between the focused spot and the characteristic microstructure. The in-situ detection system mainly includes functional modules such as confocalization, white light interferometry, and multifocal plane superposition to achieve online detection of the position, contour, and roughness of characteristic structures, thereby improving processing accuracy and quality. Confocal technology can be used to measure the morphology of various sample surfaces, white light interferometry is used to measure surface morphology or the structure of transparent films, and multifocal plane superposition technology is used to measure very rough surface morphology. The auxiliary system mainly includes an auxiliary gas purification and control system, a dust removal system, and a vibration isolation support system. The auxiliary gas purification and control system consists of a pneumatic triplet with oil and water filtration and pressure regulation functions, a pressure sensor, a precision filter, a pressure regulating valve, and a solenoid valve. It is mainly used to purge the processing area during the machining process to promptly remove residue. The dust removal system comprises a laser fume purifier, flexible hoses, and bamboo-joint suction pipes, used to remove harmful dust and odors generated during processing. The vibration isolation support system uses a single piece of natural granite to isolate vibration noise from external sources such as air conditioners, heat pumps, and air compressors. It is also equipped with an air-floating platform structure to further improve the system's ability to block external disturbances and accuracy errors caused by changes in the machine tool's center of gravity.

[0032] In a further embodiment of the present invention, the specific operation process is as follows:

[0033] Step 1: Activate the auxiliary system, motion system, and optical system sequentially to align the motion platform and preheat the laser before processing. Apply a vacuum negative pressure environment, and quickly disassemble and install the machined sample along with the clamping fixture onto the laser processing equipment using the zero-point quick-change system.

[0034] Furthermore, the auxiliary gas purification and control system is used to purge the processing area during the processing to remove residue in a timely manner. The system has a maximum working pressure of 1MPa and a filtration accuracy better than 5μm / 99%.

[0035] Furthermore, the motion system is arranged on a granite vibration isolation base platform. The platform has a small coefficient of thermal expansion, which can eliminate processing errors caused by thermal expansion and has a good vibration isolation effect, making it suitable for precision micro-hole processing.

[0036] Furthermore, the motion system includes X / Y / Z / B / C axis motion units, with the Y-axis, B-axis and C-axis arranged sequentially on the horizontal base platform, and the workpiece mounted on the C-axis stage.

[0037] Furthermore, the X-axis and Z-axis are stacked and mounted on the gantry beam, and the laser processing head is fixed on the Z-axis slide. The workpiece position change caused by the B-axis swing can be compensated by the X-axis.

[0038] Furthermore, the X-axis motion unit of the motion system adopts the SWI450LM-300 precision direct drive platform, with a stroke range of 300mm, positioning accuracy of 0.5μm, bidirectional repeatability better than 0.3μm, and straightness of 1.5μm;

[0039] Furthermore, the Y-axis motion unit of the motion system adopts the SWI225LM-300 precision direct drive platform, with a stroke range of 300mm, positioning accuracy of 0.5μm, bidirectional repeatability better than 0.3μm, and straightness of 1.5μm;

[0040] Furthermore, the Z-axis motion unit of the motion system adopts the REI130ZS-100 nano-positioning platform, with a stroke range of 100mm, positioning accuracy of 0.3μm, bidirectional repeatability better than 0.2μm, and straightness of 1.5μm;

[0041] Furthermore, the B-axis motion unit of the motion system adopts the MDRT15 precision direct drive rotary table, with a stroke range of ±90°, positioning accuracy of 5", bidirectional repeatability of 3", and axial error better than 2μm.

[0042] Furthermore, the C-axis motion unit of the motion system adopts the MDRS140 precision direct drive rotary table, with a stroke range of 360°, positioning accuracy of 5", bidirectional repeatability of 3", and axial error better than 2μm;

[0043] Furthermore, the laser is a 266nm wavelength ultraviolet nanosecond laser with a pulse repetition frequency of 1Hz~1000Hz, a pulse width better than 10ns@1kHz, an average output power ≥100W@1KHz, a maximum power >1W, and functions such as output power adjustment and external triggering.

[0044] Furthermore, the zero-point quick-change system has a repeatability accuracy better than ±0.5μm, ensuring high-precision repeatable clamping and positioning.

[0045] Step 2: Move the multi-axis motion platform and accurately calibrate the position of the thin-walled spherical shell micro-component and the spatial position of the laser focus using microscopic vision and in-situ detection system. Precisely adjust the relative positional relationship between the various feature structures on the surface of the thin-walled spherical shell micro-component and the laser beam.

[0046] Furthermore, the microscopic vision module includes an illumination beam, a beam splitter, a dichroic mirror, and an imaging lens. The dichroic mirror, model FF347-Di01-25×36, has a reflectivity of 97% for 266nm wavelength laser light and a transmittance of 93% for visible light. It is used to deflect the laser beam incident at 45° to allow the illumination beam to pass through. The beam splitter deflects the illumination beam and allows the illumination beam reflected from the sample surface to pass through.

[0047] Furthermore, the imaging lens of the microscopic vision module is an essential optical element for forming an intermediate image in an infinity-corrected optical microscope. The corresponding CCD is used to acquire the intermediate image formed by the imaging lens and transmit the image information to the industrial control computer for display on the monitor.

[0048] Furthermore, the in-situ inspection system integrates three functional measurement modes: confocal, white light interferometry, and multifocal plane superposition, to handle various workpiece surface types.

[0049] Furthermore, the in-situ detection system's confocal technology achieves a pixel resolution better than 0.09 µm;

[0050] Furthermore, the vertical resolution of the in-situ detection system using white light interferometry can reach the nanometer level;

[0051] Furthermore, the in-situ detection system features multi-focal plane stacking technology, which is fast (mm / s), has a large scanning range, and supports a large slope (up to 86°).

[0052] Step 3: Based on the structural characteristics of the microstructure to be processed and the stable and controllable removal parameters, a multi-axis motion platform CNC program is developed, the laser parameters of the laser are adjusted, and the feature structure is laser-processed. During the processing, the laser-workpiece interaction area is observed online through a coaxial vision system.

[0053] Furthermore, the coaxial vision system selects LED illuminators as the incident light source, which have a programmable function for adjusting light intensity, facilitating system integration.

[0054] Step 4: After the microstructure processing of the thin-walled spherical shell surface is completed, it is inspected by the in-situ detection system. If the expected technical specifications are not met, steps 2 and 3 are repeated based on the inspection results. If the specifications are met, the multi-axis motion platform moves to a safe position, the laser is turned off, and the micro-component of the thin-walled spherical shell is removed, completing the high-precision laser removal of the incomplete parts of the material removed during the thin-walled spherical shell machining process.

[0055] In a further embodiment of the present invention, this method addresses the problem that traditional material removal methods such as ultra-precision cutting cannot meet the manufacturing requirements for creating nanoscale precision microstructures on the surface of thin-walled spherical shell micro-components. It proposes to improve the manufacturing spatial response capability by utilizing the high spatial resolution of laser micromachining technology, enhance manufacturing stability by leveraging the absence of macroscopic forces in laser processing, and improve manufacturing contour accuracy and surface quality through the photochemical interaction mechanism between ultraviolet laser and polymer materials. This satisfies the manufacturing requirements for nanoscale surface roughness and sub-millimeter shape accuracy of multiple cross-scale irregular features on the surface of thin-walled spherical shells ranging from millimeters to sub-millimeters.

[0056] In a further embodiment of the present invention, the device employs high-precision linear motion units and rotary motion units as the main moving parts. The positioning accuracy of the X / Y / Z axis linear motion unit is better than 0.5 μm, the bidirectional repeatability is better than 0.3 μm, and the straightness is better than 1.5 μm; the positioning accuracy of the B / C axis rotary motion unit is better than 5", the bidirectional repeatability is better than 3", and the axial error is better than 2 μm. This meets the high-precision control requirements for accurate calibration of the laser beam focal position and the relative position of the feature structure with the laser beam, and is suitable for high-precision laser processing of complex micro-components such as thin-walled spherical shells under confined space.

[0057] In a further embodiment of the present invention, the method integrates laser processing of the surface microstructure of thin-walled spherical shell micro-components with in-situ detection, which can realize functions such as high-precision adjustment of the motion position, precise control of laser pulse energy, and accurate identification of feature points, thereby meeting the requirements of high-precision, stable and controllable removal of incomplete parts of the material being cut.

[0058] In a further embodiment of the present invention, the key structural component of the device—the base—is made of granite, which has a small coefficient of thermal expansion, can effectively absorb vibrations, eliminate processing errors caused by thermal expansion, and has a good vibration isolation effect. Therefore, it can greatly improve the performance of the device and is suitable for high-precision fabrication of precision / ultra-precision microstructures.

[0059] In a further embodiment of the present invention, the method has a certain degree of universality, and is not only applicable to the high-precision laser processing and manufacturing of surface feature structures of thin-walled spherical shell micro-components, but can also be further extended to the specific practice of high-precision laser creation of complex-shaped parts such as micro-steps, micro-arrays, and free-form surfaces.

[0060] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser processing device for surface microstructures of thin-walled spherical shell-like micro-components, characterized in that, include: The system comprises a gantry frame, a base (1), a B-axis motion unit (2), a Z-axis motion unit (3), an optical assembly (4), a laser (5), a beam transmission component (6), an X-axis motion unit (7), a detection head (8), a fixture (10), a zero-point quick-change system (11), a C-axis motion unit (12), and a Y-axis motion unit (13). The gantry frame is mounted on the upper surface of the base (1), and the Y-axis motion unit (13) is mounted in the middle of the upper surface of the base (1). Inside the gantry frame; the B-axis motion unit (2) is mounted on the slide of the Y-axis motion unit (13), which is used to realize the forward and backward displacement of the B-axis motion unit (2) along the Y-axis; the C-axis motion unit (12) is mounted on the rotary table of the B-axis motion unit (2), which is used to realize the rotational motion of the C-axis motion unit (12) around the B-axis; the zero-point quick-change system (11) is mounted on the rotary table of the C-axis motion unit (12), and the fixture (10) is installed on the zero-point quick-change system (11). The clamp (10) is used to clamp the thin-walled spherical shell micro-component (9). The C-axis motion unit (12) is used to realize the rotational motion of the thin-walled spherical shell micro-component (9) around the C-axis. The X-axis motion unit (7) is installed on the gantry. The Z-axis motion unit (3) is installed on the slide of the X-axis motion unit (7). The X-axis motion unit (7) is used to realize the displacement motion of the Z-axis motion unit (3) along the X-axis. The optical component (4) and the detection head (8) are both installed on the slide of the Z-axis motion unit (3). The Z-axis motion unit (3) is used to realize the displacement motion of the optical component (4) and the detection head (8) along the Z-axis. The laser (5) and the beam transmission component (6) are both installed on the top of the gantry. The laser (5) transmits the laser to the optical component (4) through the beam transmission component (6). The optical component (4) is used for surface laser processing of the thin-walled spherical shell micro-component (9) and optical microscopic imaging of the processing position.

2. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 1, characterized in that, The B-axis is parallel to the Y-axis.

3. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 1, characterized in that, The C-axis is parallel to the Z-axis.

4. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 1, characterized in that, The gantry includes: lateral vertical beams and top horizontal beams. The lower ends of the two lateral vertical beams are connected to the upper surface of the base (1), and the left and right ends of the top horizontal beam are connected to the upper ends of the two lateral vertical beams respectively. The Y-axis motion unit (13) is located between the two lateral vertical beams.

5. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 1, characterized in that, The beam transmission component (6) includes: shutter (14), beam polarization state adjustment unit, beam expander (17) and spatial filtering system (18). The beam polarization state adjustment unit includes: half-wave plate (15) and Glenling mirror (16). The laser (5), shutter (14), half-wave plate (15), Glenling mirror (16) and beam expander (17) are arranged sequentially along the axial direction. The laser beam emitted by the laser (5) passes through the shutter (14), half-wave plate (15), Glenling mirror (16) and beam expander (17) in sequence before being emitted. The beam polarization state adjustment unit is used to change the polarization state of the emitted laser beam, and the beam expander (17) is used to expand the laser beam.

6. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 5, characterized in that, The beam transmission component (6) also includes a spatial filtering system (18), through which the laser beam expanded by the beam expander (17) passes.

7. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 6, characterized in that, The beam transmission component (6) also includes a beam quality analyzer (19) and a beam splitter (20). The laser beam transmitted through the spatial filtering system (18) passes through the beam splitter (20), and the laser beam reflected by the beam splitter (20) is injected into the beam quality analyzer (19). The beam quality analyzer (19) is used to monitor and analyze the quality of the laser beam in real time.

8. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 7, characterized in that, The beam transmission component (6) also includes a second beam splitter (21) and a laser power meter (22). The laser beam transmitted through the first beam splitter (20) passes through the second beam splitter (21), and the laser beam reflected by the second beam splitter (21) enters the laser power meter (22). The laser power meter (22) is used to monitor the power of the laser beam in real time.

9. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 8, characterized in that, The optical components (4) include: a dichroic mirror (23), a processing objective (24), a beam splitter (3) (25), an imaging objective (26), a CCD camera (27), and a coaxial microscopic imaging illumination source (28). The CCD camera (27), imaging objective (26), dichroic mirror (25), beam splitter (3) (25), and processing objective (24) are arranged sequentially along the axial direction. The laser beam transmitted through the beam splitter (21) passes through the dichroic mirror (23), and the laser beam reflected by the dichroic mirror (23) passes through the processing objective (24) to perform laser processing on the thin-walled spherical shell micro-component (9). The coaxial microscopic imaging illumination source (28) is located on the side of the beam splitter (3) (25). The beam splitter (3) (25), imaging objective (26), CCD camera (27), and coaxial microscopic imaging illumination source (28) constitute a coaxial microscopic imaging system.

10. The laser processing apparatus for surface microstructures of thin-walled spherical shell micro-components according to claim 1, characterized in that, The B-axis motion unit (2) and the C-axis motion unit (12) are both precision direct drive rotary tables, the X-axis motion unit (7) and the Y-axis motion unit (13) are both precision direct drive platforms, and the Z-axis motion unit (3) is a nano-positioning stage.

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