Milling and vibration auxiliary machining multi-scale surface texture manufacturing system and method

Abstract

The invention discloses a milling and vibration auxiliary machining multi-scale surface texture manufacturing system which comprises a milling machining main shaft, a workbench base and a control system, and the control system controls the main shaft to move along a set track; a ball-end milling cutter is mounted on the main shaft, and a two-dimensional vibration platform is mounted on the workbench base; the two-dimensional vibration platform comprises a square workbench and a flexible hinge square frame located on the outer side of the square workbench. The center of four sides of the flexible hinge square frame is connected with the center of four sides of the square workbench through flexible hinges A, the four corners of the flexible hinge square frame are fixed to the workbench base, the center of four sides of the flexible hinge square frame is connected with the four corners of the workbench base through flexible hinges B, and the centers of two adjacent sides of the flexible hinge square frame are connected with a vibration device generating vibration and absorb and transmit vibration; a workpiece is fixed on the square workbench; the vibration devices generate vibration in the X-axis direction and the Y-axis direction of the square workbench respectively. According to the method, the millimeter-level basic texture and the micron-level fine texture are generated in the single machining process at the same time, the manufacturing efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of precision manufacturing technology, and in particular to a multi-scale surface texture manufacturing system and method using milling and vibration-assisted machining. Background Technology

[0002] Currently, surface texturing technology plays an increasingly important role in modern engineering applications, particularly in fields such as tribology, fluid mechanics, and biomedical engineering. Traditional surface texturing methods mainly focus on generating features at a single scale, making it difficult to meet the demands of modern applications for multi-scale surface functionality. While existing micromilling techniques can generate micron-scale surface features, they are typically limited to specific size ranges, making it difficult to achieve cross-scale texturing from millimeters to microns in a single machining operation.

[0003] Current multi-scale surface texture fabrication primarily relies on multi-step processes, requiring the combination of different processing techniques such as laser processing, chemical etching, and electrochemical machining to achieve features at different scales. This approach is not only complex and costly, but also prone to increased energy consumption, material waste, and the potential use of hazardous chemicals. Furthermore, multi-step processes suffer from poor process consistency and difficulty in controlling processing precision, severely limiting the widespread application of multi-scale textured surfaces in practical engineering.

[0004] Vibration-assisted machining (VAM) is an emerging precision manufacturing method that significantly improves surface quality, reduces cutting forces, and extends tool life by introducing high-frequency vibrations into traditional cutting processes. However, existing VAM technologies primarily focus on improving the performance of traditional machining processes, lacking research on the active design and manufacturing of multi-scale surface textures. In particular, how to organically combine VAM technology with ball end milling to achieve the simultaneous manufacturing of millimeter-level basic textures and micrometer-level fine textures still lacks systematic theoretical guidance and technical solutions.

[0005] Therefore, there is an urgent need to develop a manufacturing technology that can generate multi-scale surface textures simultaneously in a single processing step to meet the growing demand for functional surfaces in modern engineering. Summary of the Invention

[0006] This invention provides a multi-scale surface texture manufacturing system and method for milling and vibration-assisted machining to solve the technical problems existing in the prior art.

[0007] The technical solution adopted by this invention to solve the technical problems existing in the prior art is as follows:

[0008] A multi-scale surface texture manufacturing system for milling and vibration-assisted machining includes a milling spindle, a worktable base, and a control system. The control system controls the milling spindle to move along a set motion trajectory. A ball end mill is mounted on the milling spindle, and a two-dimensional vibration platform is mounted on the worktable base. The two-dimensional vibration platform includes a square worktable and a flexible hinged square frame located outside the square worktable. The four sides of the flexible hinged square frame are connected to the four sides of the square worktable via flexible hinges A, and its four corners are fixed to the worktable base. The four sides of the frame are connected to the four corners via flexible hinges B, and the centers of two adjacent sides are connected to a vibration device that generates vibration and absorbs and transmits vibration. The workpiece is fixed on the square worktable. The vibration device generates vibration in the X and Y axes of the square worktable, respectively.

[0009] Furthermore, flexible hinge A is a unidirectional notch flexible hinge; flexible hinge B is a parallel double unidirectional notch flexible hinge.

[0010] Furthermore, the two-dimensional vibration platform also includes four fixed blocks and four moving blocks; the four corners of the flexible hinge square frame are fixed to the workbench base through the four fixed blocks; the four sides of the flexible hinge square frame are fixedly connected to the four moving blocks, wherein two adjacent moving blocks are fixedly connected to the vibration end of the vibration device.

[0011] Furthermore, the vibration device includes two piezoelectric ceramic actuators, the output ends of which are respectively fixed to the centers of the adjacent two sides of the flexible hinge square frame; the control system outputs a voltage signal to the piezoelectric ceramic actuators, causing them to vibrate, and transmits the vibration to the flexible hinge square frame, and then to the square worktable through the flexible hinge A, causing the square worktable to vibrate mechanically, thereby causing the workpiece to vibrate and displace.

[0012] Furthermore, the control system includes a pulse width modulator, which outputs a voltage signal to a piezoelectric ceramic actuator. The amplitude and frequency of the square worktable vibration are adjusted by regulating the duty cycle and frequency of the pulse signal.

[0013] Furthermore, it also includes a data acquisition system, which includes a laser Doppler vibration meter; the control system is equipped with LabVIEW software. The laser Doppler vibration meter monitors the output displacement of the flexible platform in real time and sends the acquired data to the control system. The control system uses the LabVIEW software to analyze the vibration trajectory and feed back signals to realize closed-loop control of the vibration device.

[0014] The present invention also provides a method for manufacturing multi-scale surface textures by milling and vibration-assisted machining using the above-mentioned milling and vibration-assisted machining system for multi-scale surface textures. The milling spindle moves along a set motion trajectory under the control of a control system, causing the ball-end mill to mill a base texture of millimeter or sub-millimeter scale on the workpiece surface. At the same time, the vibration device is driven to generate vibrations in the X and Y axis directions of the square worktable, generating textures of micron scale on the surface of the base texture. By synchronously coordinating the feed parameters of the ball-end mill with the vibration frequency, amplitude, and phase difference parameters of the vibration device, millimeter-scale grid textures and micron-scale periodic textures are synchronously generated during a single machining process.

[0015] Further, the ball-end mill is made to mill grooves on the workpiece surface. Let R be the radius of the ball-end mill, h be the cutting depth, a be the groove spacing, and b be the width of the groove formed by a single cut. By controlling the relationship between the groove spacing a and the groove width b, three different texture morphologies are generated: a convex structure is formed when a > b, a pyramid structure is formed when a = b, and a spiky structure is formed when a < b. Let R be the radius of the ball-end mill and h be the cutting depth. The groove width b is determined by the formula The maximum texture height h1 is obtained by the formula calculation.

[0016] Further, there are four working modes of vibration-assisted machining for micron textures: no vibration, single-direction vibration in the X direction, single-direction vibration in the Y direction, and bi-directional vibration. During bi-directional vibration, the trajectories of each point on the workpiece in the X and Y axis directions are ellipses.

[0017] Further, on the XY plane, the first motion trajectory of the milling spindle is rotated 90° relative to the second motion trajectory with respect to the workpiece center, and the groove spacing and cutting depth of the ball-end mill during the two milling operations are kept consistent, forming a grid texture on the workpiece surface.

[0018] The advantages and positive effects of the present invention are as follows:

[0019] (1) Realize the integrated manufacturing of multi-scale textures: By integrating ball-end milling and vibration-assisted technologies, millimeter-scale base textures and micron-scale fine textures are simultaneously generated during a single machining process, avoiding the complexity of traditional multi-step processes, significantly improving the manufacturing efficiency, and reducing the production cost.

[0020] (2) Significantly improve the surface quality: The introduction of vibration-assisted technology effectively reduces the chip adhesion phenomenon, improves the accuracy and consistency of surface textures. Compared with non-vibration machining, surface defects are significantly reduced, and the texture definition is clearer.

[0021] (3) Surface function can be predicted and controlled: A quantitative relationship between texture parameters and surface wettability was established. As the groove spacing decreases, the surface contact angle decreases and the hydrophilicity increases, providing theoretical guidance and technical support for the design of functional surfaces.

[0022] (4) Strong controllability of texture morphology: By precisely controlling the ratio of groove spacing to groove width, three different basic texture morphologies such as protrusion, pyramid and spike can be realized; combined with the selection of four vibration modes, it provides a rich combination scheme for surface functional design to meet different application needs.

[0023] (5) Equipment structure innovation: The two-degree-of-freedom vibration platform adopts a layered design of double parallel flexible hinge outer frame and single beam hinge inner layer, which effectively reduces the coupling effect between vibration directions, improves vibration accuracy and stability, and the rounded corner flexible hinge design reduces stress concentration and improves equipment reliability.

[0024] (6) Environmental friendliness: Compared with traditional multi-step processes, the present invention avoids chemical etching and other process steps, reduces the use of harmful chemicals, reduces material waste and energy consumption, and meets the development requirements of green manufacturing.

[0025] (7) High processing accuracy and repeatability: Real-time monitoring by laser Doppler vibration meter and precise control by LABVIEW software ensure the accuracy of vibration trajectory and the stability of processing, realizing high-precision and high-repeatability multi-scale texture manufacturing. Attached Figure Description

[0026] Figure 1 : A schematic diagram of a multi-scale surface texture manufacturing system for milling and vibration-assisted machining according to the present invention;

[0027] Figure 2 : A schematic diagram of a two-dimensional vibration platform structure according to the present invention;

[0028] Figure 3 The present invention discloses a multi-scale surface texture manufacturing system for milling and vibration-assisted machining, which generates three different texture morphologies by controlling the relationship between the groove spacing a and the groove width b.

[0029] Figure 4 A schematic diagram illustrating the creation of different millimeter-level textures using a multi-scale surface texture manufacturing system that combines milling and vibration-assisted machining, with different toolpaths planned.

[0030] Figure 5 Simulation results of the multi-scale mesh texture and two-dimensional vibration-assisted mesh element of the present invention.

[0031] In the diagram: 1. Flexible hinge A; 2. Flexible hinge B; 3. Ball end mill; 4. Workpiece; 5. Workpiece fixing bolt; 6. Workpiece fixing bolt hole; 7. Fixing block; 8. Support base; 9. Piezoelectric ceramic actuator; 10. Moving block; 11. Fixing block fixing screw; 12. Two-dimensional vibration platform; 13. Preload bolt; 14. Fixing block through hole.

[0032] O is the center of the ball end mill, R is the radius of the ball end mill, h is the depth of cut, b is the width of the groove formed in a single cut, and a is the groove spacing. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0034] In the description of this invention, the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection through intermediate components; or an electrical connection or signal transmission. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0035] Please see Figures 1 to 5 A multi-scale surface texture manufacturing system for milling and vibration-assisted machining includes a milling spindle, a worktable base, and a control system. The control system controls the milling spindle to move along a set motion trajectory. A ball end mill 3 is mounted on the milling spindle, and a two-dimensional vibration platform 12 is mounted on the worktable base. The two-dimensional vibration platform 12 includes a square worktable and a flexible hinged square frame located outside the square worktable. The four sides of the flexible hinged square frame are connected to the four sides of the square worktable via flexible hinges A1, and its four corners are fixed to the worktable base. The four sides of the frame are connected to the four corners via flexible hinges B2, and the centers of two adjacent sides are connected to a vibration device that generates vibration and absorbs and transmits vibration. A workpiece 4 is fixed on the square worktable. The vibration device generates vibration in the X and Y axis directions of the square worktable, respectively.

[0036] The two-dimensional vibration platform 12, as a two-degree-of-freedom vibration auxiliary platform, adopts an innovative layered flexible mechanism design. The double parallel flexible hinge structure of the outer frame effectively improves the compressive stiffness and reduces the coupling effect of the two vibration directions. The single beam hinge design of the inner mechanism expands the vibration range. The overall structure adopts rounded corner flexible hinges to improve motion accuracy and reduce stress concentration.

[0037] Preferably, the flexible hinge A1 can be a one-way notch flexible hinge.

[0038] Preferably, the flexible hinge B2 can be a parallel double unidirectional notch flexible hinge.

[0039] Preferably, the two-dimensional vibration platform 12 may further include four fixed blocks 7 and four moving blocks 10; the four corners of the flexible hinge square frame are fixed to the workbench base by the four fixed blocks 7; the four sides of the flexible hinge square frame are fixed to the four moving blocks 10, wherein two adjacent moving blocks 10 are fixed to the vibration end of the vibration device.

[0040] Preferably, the vibration device may include two piezoelectric ceramic actuators 9, the output ends of which are respectively fixed to the centers of adjacent sides of the flexible hinge square frame. The control system outputs a voltage signal to the piezoelectric ceramic actuators 9, causing them to vibrate and transmit the vibration to the flexible hinge square frame. This vibration is then transmitted to the square worktable via the flexible hinge A1, causing the worktable to vibrate at a frequency greater than 200Hz, thereby causing the workpiece 4 to vibrate and displace. A pre-tightening device is provided to ensure that the pre-tightening force is consistent in both vibration directions.

[0041] Preferably, the control system may include a pulse width modulator, which outputs a voltage signal to the piezoelectric ceramic actuator 9, and the amplitude and frequency of the square worktable vibration can be adjusted by adjusting the duty cycle and frequency of the pulse signal.

[0042] Preferably, the system may also include a data acquisition system, which may include a laser Doppler vibration meter. The control system may be equipped with LabVIEW software. The laser Doppler vibration meter can monitor the output displacement of the flexible platform in real time and send the acquired data to the control system. The control system can use the LabVIEW software to analyze the vibration trajectory and provide feedback signals to achieve closed-loop control of the vibration device. This enables precise control and quality monitoring of the vibration trajectory, ensuring the stability and repeatability of multi-scale texture manufacturing.

[0043] LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is a graphical programming platform developed by National Instruments (NI, National Instruments Corporation) in the United States and is widely used in fields such as data acquisition, instrument control, industrial automation, and signal processing.

[0044] The present invention also provides a method for manufacturing multi-scale surface textures by milling and vibration-assisted machining using the above-mentioned multi-scale surface texture manufacturing system for milling and vibration-assisted machining. The milling spindle moves along a set motion trajectory under the control of a control system, causing the ball-end mill 3 to mill on the surface of the workpiece 4 to generate a base texture at the millimeter or sub-millimeter scale. At the same time, the vibration device is driven to generate vibrations in the X and Y axis directions of the square workbench, generating a texture at the micron scale on the surface of the base texture; by synchronously coordinating and controlling the feed parameters of the ball-end mill 3 and the vibration frequency, amplitude, and phase difference parameters of the vibration device, a millimeter-scale grid texture and a micron-scale periodic texture are synchronously generated during a single machining process.

[0045] Preferably, the ball-end mill 3 can be used to mill grooves on the surface of the workpiece 4. Let R be the radius of the ball-end mill 3, h be the cutting depth, a be the groove spacing, and b be the width of the groove formed by a single cut; different three different texture morphologies can be generated by controlling the relationship between the groove spacing a and the groove width b: a convex structure is formed when a > b, a pyramid structure is formed when a = b, and a spiky structure is formed when a < b; let R be the radius of the ball-end mill 3 and h be the cutting depth; where the groove width b can be calculated by the formula and determined; the maximum texture height h1 can be obtained by the formula This provides a rich selection of surface morphologies for surface functional design.

[0046] The formation of the multi-scale texture synchronously controls the millimeter-scale parameters and micron-scale parameters by synchronously coordinating and controlling the feed parameters of the ball-end mill 3 and the vibration frequency, amplitude, and phase difference parameters of the vibration device. The millimeter-scale parameters include a ball-end mill 3 radius R of 50 - 600 μm, a cutting depth h of 50 - 300 μm, and a groove spacing a of 50 - 600 μm; the micron-scale parameters include a vibration frequency of 2000 - 6000 Hz, a vibration amplitude of 0 - 3 μm, and a feed per tooth of 1 - 10 μm; the textures at the two scales are generated simultaneously during the machining process, forming a composite surface morphology with a hierarchical structure feature.

[0047] Multi-scale texture manufacturing realizes the synchronous generation of textures at two scales by establishing a coordinated control relationship between millimeter-scale parameters and micron-scale parameters, significantly reducing chip adhesion phenomena, improving the accuracy and consistency of surface textures, and enabling controllable adjustment of surface wettability by adjusting texture parameters.

[0048] Preferably, vibration-assisted machining can have the following four micron-scale texture generation modes: no vibration, unidirectional X-axis vibration, unidirectional Y-axis vibration, and bidirectional vibration; wherein, in bidirectional vibration, the trajectories of each point on the workpiece 4 in the X and Y axes are elliptical. Bidirectional vibration achieves circular trajectory motion through 90° phase difference control, providing diverse options for precise control of micron-scale textures.

[0049] During bidirectional vibration, the trajectory of workpiece 4 is elliptical, and the trajectory equation in the X-axis direction is: x w =Asin(2πf a t+θ x The equation of the trajectory along the Y-axis is: y w =Bsin(2πf a t+θ y ); where A and B are the vibration amplitudes, f a Let θ be the vibration frequency. x θ is the phase angle in the X-axis direction. y Let t be the phase angle in the Y-axis direction and t be the time. The phase difference of the bidirectional vibration is set to 90° to achieve a circular trajectory.

[0050] Preferably, in the XY plane, the first and second motion trajectories of the milling spindle can rotate 90° relative to the center of workpiece 4, and the groove spacing and cutting depth of the ball end mill 3 in the two milling operations remain consistent, forming a mesh texture on the surface of workpiece 4. This mesh texture on the surface of workpiece 4 is achieved through two intersecting milling trajectories. The first milling operation is roughly along the X-axis, and the second milling operation is roughly along the Y-axis, with the groove spacing and cutting depth remaining consistent in both operations.

[0051] The structure, workflow, and working principle of the present invention are further illustrated below with reference to a preferred embodiment:

[0052] As attached Figures 1 to 5 As shown, a multi-scale surface texture manufacturing system for milling and vibration-assisted machining includes a milling spindle, a worktable base, and a control system. The control system controls the milling spindle to move along a set motion trajectory. The system is characterized by having a ball end mill 3 mounted on the milling spindle and a two-dimensional vibration platform 12 mounted on the worktable base. The two-dimensional vibration platform 12 includes a square worktable and a flexible hinged square frame located outside the square worktable. The four sides of the flexible hinged square frame are connected to the four sides of the square worktable via flexible hinges A1, and its four corners are fixed to the worktable base. The four sides of the frame are connected to its four corners via flexible hinges B2, and the centers of two adjacent sides are connected to a vibration device that generates vibration and absorbs and transmits the vibration. A workpiece 4 is fixed on the square worktable. The vibration device generates vibrations in the X and Y axes of the square worktable.

[0053] Flexible hinge A1 is a one-way angled circular notch flexible hinge, also known as a single rounded corner straight beam flexible hinge.

[0054] Flexible hinge B2 is a parallel double unidirectional angle circular notch flexible hinge, also known as a double rounded corner straight beam type flexible hinge parallel parallel structure.

[0055] The two-dimensional vibration platform 12 includes a centrally located square worktable, four fixing blocks 7 for fixing, four motion blocks 10 for transmitting motion, four inner single-rounded straight beam flexible hinges, eight outer double-rounded straight beam flexible hinges in parallel, and multiple workpiece fixing bolt holes 6 for fixing the workpiece 4. The workpiece is fixed on the square worktable by threading the workpiece fixing bolts 5 through the through holes on the workpiece 4 and the workpiece fixing bolt holes 6.

[0056] The four corners of the flexible hinge square frame are fixed to the workbench base by four fixed blocks 7; the four sides of the flexible hinge square frame are fixed to four moving blocks 10, and two adjacent moving blocks 10 are fixed to the vibration end of the vibration device.

[0057] The vibration device includes two piezoelectric ceramic actuators 9, the output ends of which are respectively fixed to the centers of the adjacent two sides of the flexible hinge square frame. The control system outputs a voltage signal to the piezoelectric ceramic actuators 9, causing them to vibrate and transmit the vibration to the flexible hinge square frame. The vibration is then transmitted to the square worktable through the flexible hinge A1, causing the square worktable to vibrate mechanically, which in turn causes the workpiece 4 to vibrate and displace.

[0058] A multi-scale surface texture manufacturing system for milling and vibration-assisted machining also includes a support base 8 for mounting and fixing a flexible hinged square frame, the support base 8 being directly fixed to the worktable base by bolts.

[0059] The interior of the support base 8 is connected to the fixing blocks 7 of the two-dimensional vibration platform 12 via bolts, serving to support and fix the two-dimensional vibration platform 12. The four fixing blocks 7 can be fixedly connected to the four inner corners of the support base 8 with screws, thus providing a fixing function. Alternatively, the fixing blocks 7 can be integrated with the support base 8. When integrated, the four fixing blocks 7 have through holes, through which fixing screws 11 pass and are threaded into the bolt holes of the worktable base to fix the four corners of the flexible hinge square frame.

[0060] The worktable is located at the center of the support base 8. The worktable is connected to four moving blocks 10 via four single-rounded straight beam flexible hinges. Each moving block 10 has parallel structures of double-rounded straight beam flexible hinges on both sides. One end of each parallel structure is fixedly connected to the moving block 10, and the other end is fixedly connected to a corresponding fixed block 7, which in turn is fixedly connected to the worktable base. Two adjacent moving blocks 10 are connected to two piezoelectric ceramic actuators 9 arranged perpendicularly to each other in the same horizontal plane, enabling high-precision two-degree-of-freedom motion of the worktable.

[0061] The control system includes a pulse width modulator, which outputs a voltage signal to a piezoelectric ceramic actuator 9. The amplitude and frequency of the square worktable vibration are adjusted by regulating the duty cycle and frequency of the pulse signal.

[0062] A multi-scale surface texture manufacturing system for milling and vibration-assisted machining also includes a data acquisition system, which includes a laser Doppler vibrometer. The control system is equipped with LabVIEW software. The laser Doppler vibrometer monitors the output displacement of the flexible platform in real time and sends the acquired data to the control system. The control system uses the LabVIEW software to analyze the vibration trajectory and outputs signals to control the operation of the vibration device.

[0063] The output end of the encapsulated cylindrical piezoelectric ceramic actuator 9 is fixedly connected to the moving block 10 of the two-dimensional vibration platform 12, and a pre-tightening force is provided to the encapsulated cylindrical piezoelectric ceramic actuator 9 through a pre-tightening mechanism. The pre-tightening mechanism includes a pre-tightening module and a pre-tightening bolt 13. The pre-tightening module is cylindrical, with a circular groove A on its upper bottom surface whose inner diameter matches the outer diameter of the piezoelectric ceramic actuator, and a circular groove B on its lower bottom surface whose inner diameter matches the nominal diameter of the pre-tightening bolt 13. The pre-tightening bolt 13 is threadedly connected to the side wall of the support base 8, and the threaded end of the pre-tightening bolt 13 extends into the circular groove B of the pre-tightening module located in the support base 8. One end of the cylindrical piezoelectric ceramic actuator 9 is located in the circular groove A, and the other end is connected to the moving block 10.

[0064] The preload bolt 13 is rotated so that its end abuts against the cylindrical preload module, applying a horizontal force to the preload module, which in turn applies horizontal pressure to the cylindrical piezoelectric ceramic actuator 9, thereby providing preload force to the encapsulated cylindrical piezoelectric ceramic actuator 9.

[0065] The encapsulated cylindrical piezoelectric ceramic actuator 9 is supplied with voltage by a control system, which converts an electrical signal into a vibration displacement signal and transmits it to the two-dimensional vibration platform 12, causing the central workbench of the two-dimensional vibration platform 12 to perform high-frequency mechanical vibrations, thereby driving the workpiece 4 to generate vibration displacement. By adjusting the input power and frequency of the piezoelectric ceramic controller, the amplitude and frequency of the central workbench vibration can be adjusted.

[0066] The support base 8 can be a square frame body. The four corners of the square frame body are square columns. Among them, two adjacent sides are cuboids, and the other two adjacent sides are U-shaped bodies. The cuboid, square column, cuboid, square column, U-shaped body, square column, U-shaped body, and square column are connected in sequence to enclose a square frame body.

[0067] The encapsulated cylindrical piezoelectric ceramic actuator 9 and the preloading module are connected to each other and are located inside the U-shaped body. The preloading bolts 13 are installed on the side walls of the U-shaped body to apply forces to the cylindrical piezoelectric ceramic actuator 9 in the X-axis direction and Y-axis direction respectively.

[0068] Please refer to Figure 3 , where O is the center of the ball end mill 3, R is the radius of the ball end mill 3, h is the cutting depth, a is the groove spacing, and b is the groove width formed by a single cut.

[0069] During the ball end milling process, the ball end mill 3 cuts along a preset tool path. According to the contour geometric relationship of the ball end mill 3, the radius R of the ball end mill 3 and the cutting depth h jointly determine the groove width b formed by a single cut. The calculation formula is . By adjusting the relationship between the adjacent groove spacing a and the groove width b, three different millimeter-scale basic texture morphologies can be achieved. When a > b, there is a gap between adjacent machining areas, forming a convex-type millimeter-scale texture; when a = b, adjacent machining areas just meet, forming a pyramid-type millimeter-scale texture; when a < b, adjacent machining areas overlap, forming a spike-type millimeter-scale texture. At this time, the maximum texture height h1 is determined by the formula determined.

[0070] The formation of the multi-scale texture is achieved by synchronously coordinating and controlling the feed parameters of the ball end mill 3 and the vibration frequency, amplitude, and phase difference parameters of the vibration device to synchronously control the millimeter-scale parameters and micron-scale parameters.

[0071] For example: the millimeter-scale parameters include the radius R of the ball end mill 3 being 200 μm, the cutting depth h being 100 μm, and the groove spacing a being 200 μm; the micron-scale parameters include the vibration frequency of 6000 Hz, the vibration amplitude of 2 μm, and the feed per tooth of 10 μm; the textures of the two scales are generated simultaneously during the machining process, forming a composite surface topography with a hierarchical structure feature.

[0072] Please refer to Figure 4The arrows above indicate the two cross-shaped tool paths of the ball end mill 3 on the XY plane, which represent the movement trajectory of the milling spindle on the XY plane.

[0073] The mesh texture is created through two cross-cutting milling operations. The first milling is performed along the X-direction, and the second milling is performed along the Y-direction perpendicular to the first feed direction. The groove spacing and cutting depth are kept consistent in both milling operations. Depending on the relationship between the spacing and width, three tool paths are ultimately formed, corresponding to millimeter-level texture mesh unit shapes: boss-type millimeter-level texture array, pyramid-type millimeter-level texture array, and spike-type millimeter-level texture array.

[0074] The above method can significantly reduce chip adhesion, improve the accuracy and consistency of surface texture, and achieve controllable adjustment of surface wettability by adjusting the groove spacing. As the groove spacing decreases, the surface contact angle decreases and the hydrophilicity increases.

[0075] Please see Figure 5 This displays different multi-scale composite texture structures generated under different feed parameters of the ball end mill 3 and the vibration frequency, amplitude, and phase difference parameters of the vibration device. Among them:

[0076] (a) The ball end mill has a diameter of 400 μm, a depth of cut of 100 μm, a spacing of 400 μm, and a feed per tooth of 10 μm; the vibration device has a vibration frequency of 6000 Hz, a vibration amplitude of 2 μm, and a phase difference of 90 degrees.

[0077] (b) The ball end mill has a diameter of 400 μm, a depth of cut of 100 μm, a spacing of 340 μm, and a feed per tooth of 10 μm; the vibration device has a vibration frequency of 6000 Hz, a vibration amplitude of 2 μm, and a phase difference of 90 degrees.

[0078] (c) The ball end mill has a diameter of 400 μm, a depth of cut of 100 μm, a spacing of 200 μm, and a feed per tooth of 10 μm; the vibration device has a vibration frequency of 6000 Hz, a vibration amplitude of 2 μm, and a phase difference of 90 degrees.

[0079] The formation of multi-scale composite textures is achieved through simultaneous manufacturing at both the millimeter and micrometer scales. While the ball end mill 3 performs millimeter-scale texture machining on the surface of the workpiece 4, a two-dimensional vibration platform 12 drives the workpiece 4 to vibrate at high frequency, causing a periodic change in the relative motion trajectory between the tool and the workpiece 4. This superimposes micrometer-scale fine textures onto the millimeter-scale base texture. The resulting composite textures include: boss-type millimeter-scale textures combined with vibration-assisted micrometer-scale textures, pyramid-type millimeter-scale textures combined with vibration-assisted micrometer-scale textures, spike-type millimeter-scale textures combined with vibration-assisted micrometer-scale textures, and corresponding unit texture composite structures.

[0080] The ball end mill 3, worktable base, square worktable, flexible hinge A1, flexible hinge B2, one-way notch flexible hinge, parallel double one-way notch flexible hinge, fixed block 7, moving block 10, vibration device, piezoelectric ceramic actuator 9, pre-tightening mechanism, pre-tightening module, pre-tightening bolt 13, pulse width modulator, data acquisition system, laser Doppler vibration meter, support base 8 and other devices and structures mentioned above can all adopt the devices and structures in the prior art, or adopt the devices and structures in the prior art and or construct them using conventional technical means.

[0081] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The patent scope of the present invention should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention still fall within the patent scope of the present invention.

Claims

1. A multi-scale surface texture manufacturing system for milling and vibration-assisted machining, comprising a milling spindle, a worktable base, and a control system, wherein the control system controls the milling spindle to move along a set motion trajectory; characterized in that, A ball end mill is mounted on the milling spindle, and a two-dimensional vibration platform is mounted on the worktable base. The two-dimensional vibration platform includes a square worktable and a flexible hinged square frame located outside the square worktable. The four centers of the flexible hinged square frame are connected to the four centers of the square worktable via flexible hinges A, and its four corners are fixed to the worktable base. The four centers of the frame are connected to the four corners via flexible hinges B, and the centers of two adjacent sides are connected to the vibration device that generates vibration and absorbs and transmits vibration. The workpiece is fixed on the square worktable. The vibration device generates vibration in the X and Y axis directions of the square worktable, respectively.

2. The multi-scale surface texture manufacturing system for milling and vibration-assisted machining according to claim 1, characterized in that, Flexible hinge A is a one-way notch flexible hinge; flexible hinge B is a parallel double one-way notch flexible hinge.

3. The multi-scale surface texture manufacturing system for milling and vibration-assisted machining according to claim 1, characterized in that, The two-dimensional vibration platform also includes four fixed blocks and four moving blocks; the four corners of the flexible hinge square frame are fixed to the workbench base through the four fixed blocks; the four sides of the flexible hinge square frame are fixed to the four moving blocks, and the adjacent two moving blocks are fixed to the vibration end of the vibration device.

4. The multi-scale surface texture manufacturing system for milling and vibration-assisted machining according to claim 1, characterized in that, The vibration device includes two piezoelectric ceramic actuators. The output ends of the two piezoelectric ceramic actuators are respectively fixed to the center of the adjacent two sides of the flexible hinge square frame. The control system outputs a voltage signal to the piezoelectric ceramic actuators, causing the piezoelectric ceramic actuators to vibrate. The vibration is then transmitted to the flexible hinge square frame, and then transmitted to the square worktable through the flexible hinge A, causing the square worktable to vibrate mechanically, thereby causing the workpiece to vibrate and displace.

5. The multi-scale surface texture manufacturing system for milling and vibration-assisted machining according to claim 4, characterized in that, The control system includes a pulse width modulator, which outputs a voltage signal to a piezoelectric ceramic actuator. The amplitude and frequency of the square worktable vibration are adjusted by regulating the duty cycle and frequency of the pulse signal.

6. The multi-scale surface texture manufacturing system for milling and vibration-assisted machining according to claim 1, characterized in that, It also includes a data acquisition system, which includes a laser Doppler vibration meter; the control system is equipped with LabVIEW software. The laser Doppler vibration meter monitors the output displacement of the flexible platform in real time and sends the acquired data to the control system. The control system uses LabVIEW software to analyze the vibration trajectory and feed back signals to realize closed-loop control of the vibration device.

7. A method for manufacturing multi-scale surface texture using a milling and vibration-assisted machining multi-scale surface texture manufacturing system according to any one of claims 1 to 6, characterized in that, The milling spindle moves along a set motion trajectory under the control of the control system, causing the ball end mill to mill a basic texture on the workpiece surface at the millimeter or sub-millimeter scale. At the same time, the vibration device is driven to vibrate in the X and Y directions of the square worktable, generating a micrometer-scale texture on the surface of the basic texture. By synchronously coordinating the feed parameters of the ball end mill with the vibration frequency, amplitude, and phase difference parameters of the vibration device, millimeter-level mesh texture and micrometer-level periodic texture are generated simultaneously in a single machining process.

8. The multi-scale surface texture manufacturing method using milling and vibration-assisted machining according to claim 7, characterized in that, The ball-end mill is used to mill grooves on the workpiece surface. Let \(R\) be the radius of the ball-end mill, \(h\) be the cutting depth, \(a\) be the groove spacing, and \(b\) be the groove width formed by a single cut. By controlling the relationship between the groove spacing \(a\) and the groove width \(b\), three different texture morphologies are generated: when \(a > b\), a convex structure is formed; when \(a = b\), a pyramid structure is formed; when \(a < b\), a spike structure is formed. Let \(R\) be the radius of the ball-end mill and \(h\) be the cutting depth. The groove width \(b\) is determined by the formula The maximum texture height \(h_1\) is obtained by the formula calculated.

9. The multi-scale surface texture manufacturing method using milling and vibration-assisted machining according to claim 7, characterized in that, Vibration-assisted machining has the following four micron-textured working modes: no vibration, unidirectional X-axis vibration, unidirectional Y-axis vibration, and bidirectional vibration; among them, in bidirectional vibration, the trajectories of each point on the workpiece in the X and Y axis directions are ellipses.

10. The multi-scale surface texture manufacturing method using milling and vibration-assisted machining according to claim 7, characterized in that, In the XY plane, the first and second motion trajectories of the milling spindle rotate 90° relative to the workpiece center, and the groove spacing and cutting depth of the ball end mill remain consistent in the two milling operations, forming a grid texture on the workpiece surface.

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