A method and device for processing micro-pit structure on surface of thin-walled spherical shell type complex micro-component based on coordinate transformation

Abstract

The application discloses a kind of complex microstructure processing method and device of thin-walled spherical shell type complex microstructure surface micro-pit based on coordinate conversion, it is related to ultra-precision machining technical field, to solve the problem that existing coordinate conversion method cannot be applied to the conversion and generation of five-axis linkage ultra-precision machining coordinates of thin-walled spherical shell type complex microstructure. Including the following steps: S1, construct microsphere target full-surface micro-pit point set initial coordinates;S2, rotate C axis by a certain angle, make microsphere target surface arbitrary to-be-processed spatial micro-pit point rotate to the horizontal plane where C axis movement unit axis is located, B axis rotates a certain angle, make the angle between milling shaft axis and Z axis linear motion unit and the angle between the line connecting to-be-processed point-workpiece coordinate system origin and Z axis linear motion unit direction are equal, obtain the coordinates of B axis and C axis and X / Y / Z linear axis movement unit under workpiece coordinate system;S3, convert the coordinates of workpiece coordinate system into processing coordinates under processing coordinate system, carry out high-precision processing to micro-pit structure.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision machining technology, and more specifically, to a method and apparatus for machining micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation. Background Technology

[0002] With the development of aerospace, biomedicine, microelectromechanical systems (MEMS), and other fields, the demand for various high-precision complex micro-components is increasing. For example, a complex micro-component made of CH composite material with a diameter of 1–5 mm and a wall thickness of 20–120 μm has been widely used in nuclear physics experiments and new energy exploration due to its low density, atomic number, and excellent machinability. To further clarify the tool-material interaction mechanism and reveal the influence of material properties on practical engineering applications, it is necessary to process dozens of micrometer-scale characteristic micro-pit structures on the entire surface of the aforementioned micro-components, requiring micrometer-level shape accuracy, nanometer-level surface roughness, and micrometer-level pit spacing error. This poses a severe challenge to ultra-precision manufacturing processes and machining coordinate transformation methods.

[0003] For high-precision machining of complex micro-spherical shell micro-pit structures with full-surface micro-cavities under micro-scale constraints, a dedicated ultra-precision multi-axis linkage device is required. This necessitates the design of specialized micro-structure machining processes and micro-pit structure point set coordinate generation algorithms. Furthermore, based on the device structure and machining coordinate system, the point set coordinates must be rationally designed and transformed to achieve stable and controllable removal of the micro-pit structures. The key to ensuring the quality of micro-structure machining lies in how to uniformly distribute and generate the coordinates of the micro-pit structures based on the micro-target size and the specific number of micro-pit structures, and then transform them to the machining coordinate system. This, combined with writing the CNC program based on the micro-structure dimensional characteristics, is crucial. Existing ultra-precision machining devices mainly rely on two-axis and three-axis ultra-precision manufacturing technologies. Five-axis linkage ultra-precision machining is primarily designed for simple basic surfaces such as planes or cylinders. For complex micro-components, limitations in control program writing and process formulation mean that many factors influence the accuracy of the results, making precise implementation difficult. Coordinate transformation methods for regular basic contours and single-feature structures are not applicable to the transformation and generation of coordinates for machining complex micro-components such as thin-walled spherical shells. Summary of the Invention

[0004] The technical problem to be solved by this invention is:

[0005] Existing coordinate transformation methods are not applicable to the transformation and generation of coordinates for five-axis linkage ultra-precision machining of complex micro-components such as thin-walled spherical shells.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] This invention provides a method for fabricating micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation, comprising the following steps:

[0008] S1. Point set coordinate generation: By observing with a high-resolution CCD camera, the axis of the C-axis motion unit and the axis of the milling axis are in the same plane. The high-resolution CCD camera is adjusted to take pictures of the workpiece area, the diameter of the microsphere target is identified and obtained, and the workpiece coordinate system is established with the center of the microsphere target as the coordinate origin to generate the initial coordinates of the micro-pit point set on the entire surface of the microsphere target.

[0009] S2. Spatial coordinate transformation: Based on the initial coordinates of the micro-pit point set on the entire surface of the micro-spherical target, the C-axis is rotated by a certain angle so that any micro-pit point to be processed on the surface of the micro-spherical target is rotated to the horizontal plane where the axis of the C-axis motion unit is located. The B-axis is rotated by a certain angle so that the angle between the milling axis and the Z-axis linear motion unit is equal to the angle between the line connecting the origin of the workpiece coordinate system and the direction of the Z-axis linear motion unit. The coordinates of the B-axis and C-axis, as well as the coordinates of the X / Y / Z linear axis motion units in the workpiece coordinate system, are obtained.

[0010] S3. Machining coordinate calibration: Establish a machining coordinate system and convert the coordinates of the workpiece coordinate system into machining coordinates under the machining coordinate system to perform high-precision machining of the micro-pit structure.

[0011] Furthermore, S1 includes the following steps:

[0012] S1-1. Adjust the CCD camera to point at the microsphere target and perpendicular to the horizontal plane to obtain an image of the microsphere target. Obtain the maximum outer dimension of the microsphere target, i.e., the diameter of the microsphere target, through image processing.

[0013] S1-2, with the center of the complex micro-spherical target as the origin O. w With the negative direction of the Z-axis linear motion unit as Z... w +, with the positive direction of the X-axis linear motion unit as X w +, with the positive direction of the Y-axis linear motion unit as Y w +, Establish workpiece coordinate system O w -X w Y w Z w ;

[0014] S1-3. In the workpiece coordinate system, the number N of the micro-pit structures to be machined on the entire surface of the thin-walled microsphere target is... u The initial point set coordinates of the micro-pit structure on the entire surface of the microsphere target were generated based on the Fibonacci algorithm.

[0015] Furthermore, the initial point set coordinates of the micro-pit structure on the entire surface of the microsphere target, generated by the Fibonacci algorithm as described in S1-3, specifically involves, along O... w Z w The direction uniformly divides the microsphere target shell into Nu If the i-th layer is a shell, then the coordinate of the midpoint Z in the thickness direction of the i-th layer is... w for:

[0016]

[0017] D is the diameter of the microsphere target;

[0018] S1-4, by X w Xiang and Y w The coordinates follow an arithmetic sequence distribution, yielding the micro-pit structure X on the surface of the thin-walled spherical shell. w Xiang and Y w To coordinates:

[0019]

[0020]

[0021] f represents the golden ratio.

[0022] Furthermore, in S1-3, the side surfaces of the segmented Nu layer are equivalent to toroids, and the area of ​​each toroid is πD. 2 / Nu ensures a uniform distribution of the micro-pit point set on a macroscopic scale.

[0023] Furthermore, S2 includes the following steps:

[0024] S2-1, The workpiece coordinate system contains any point N to be machined. i coordinates (x) wi ,y wi ,z wi ), to X w O w Y w Projecting in the plane yields the projection point Pi. Based on the angle εi between the line connecting the projection point Pi and the origin Ow of the workpiece coordinate system and the Yw axis, the C-axis coordinates corresponding to the machining point Ni are obtained.

[0025] Specifically, when any point N to be processed i (x wi ,y wi Located in X w O w Y w The second quadrant of the coordinate system, i.e., x wi <0,y wi If the value is greater than 0, then the C-axis rotation angle corresponding to the point Ni to be processed is (π / 2 - εi), and the corresponding C-axis coordinate is:

[0026]

[0027] When any point N to be processed i (x wi ,ywi Located in X w O w Y w The first quadrant of the coordinate system, i.e., x wi >0,y wi >0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is (π / 2 + εi), then the corresponding C-axis coordinates are:

[0028]

[0029] When any point N to be processed i (x wi ,y wi Located in X w O w Y w The fourth quadrant of the coordinate system, i.e., x wi >0,y wi <0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is The corresponding C-axis coordinate is:

[0030]

[0031] When any point N to be processed i (x wi ,y wi Located in X w O w Y w The third quadrant of the coordinate system, i.e., x wi <0,y wi <0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is The corresponding C-axis coordinate is:

[0032]

[0033] S2-2, From any point N to be processed in the workpiece coordinate system i (x wi ,y wi ,z wi ), connection point N i With the center of the microsphere target O w denoted as N i O w According to N i O w With respect to the workpiece coordinate system Z w The positive angle βi between the axes gives the B-axis coordinates corresponding to machining point Ni as follows:

[0034]

[0035] S2-3, Any point N to be machined in the workpiece coordinate system i (x wi ,y wi ,z wi Rotation of C axis i After adjusting the angle, rotate to the workpiece coordinate system X. w O w Z w In the plane, and at the origin O of the machining coordinate system w Connecting lines and Z w The positive angle is B i Then to X w O w Y w Its projection in the plane, on O w X w - The projection point is denoted as H. i Then O w H i That is, the point N to be processed. i Corresponding X w coordinate X wi From the coordinate transformation relationship, we get:

[0036]

[0037] S2-4. Any point N to be machined in the workpiece coordinate system i (x wi ,y wi ,z wi Rotation of C axis i After adjusting the angle, rotate to X. w O w Z w In the plane, its Y w coordinate Y wi =0; Rotate B axis i After the angle, its Z w With the coordinates remaining unchanged, we can see from formula (1):

[0038]

[0039] Furthermore, S3 includes the following steps:

[0040] S3-1, Control the X / Y / Z linear motion unit to perform tool setting operation;

[0041] S3-2. Set the tool setting completion point as the machining origin and set it as the origin O of the machining coordinate system. m With the positive direction of the Z-axis linear motion unit as Z... m +, with the positive direction of the X-axis linear motion unit as X m +, with the positive direction of the Y-axis linear motion unit as Ym +, Establish machining coordinate system O m -X m Y m Z m ;

[0042] S3-3, Place any micro-pit point N to be machined in the workpiece coordinate system. i (X wi ,Y wi Z wi B wi C wi Convert to machining coordinates N in the machining coordinate system i (X i ,Y i Z i B i C i );

[0043] Any micro-pit point N to be processed i (X i ,Y i Z i B i C i In the machining coordinate system, X m Y m and Z m The coordinates of the directions are as follows:

[0044]

[0045] Y i =Y wi =0 (12)

[0046]

[0047] Any micro-pit point N to be processed i (X i ,Y i Z i B i C i In the machining coordinate system, B i The coordinates are:

[0048]

[0049] Any micro-pit point N to be processed i (X i ,Y i Z i B i C i In the machining coordinate system, C i The coordinates are:

[0050]

[0051] After completing the spatial transformation of the coordinates of the micro-pit structures on the entire surface of the complex micro-component of the thin-walled spherical shell, the micro-pit structures are processed according to the processing coordinates.

[0052] A processing device for micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells is disclosed. The processing device is a five-axis linkage machine tool, including a vacuum adsorption fixture assembly. The vacuum adsorption fixture assembly includes a hollow adsorption base and an adsorption chuck. The end of the adsorption chuck is trumpet-shaped and used to adsorb the workpiece by vacuum. The inclined side of the end section of the adsorption chuck forms an angle of 35° to 46° with the central axis. The ratio of the inner diameter of the port of the adsorption chuck used to adsorb the workpiece to the diameter of the target ball to be processed is (0.6 to 0.8):1.

[0053] Furthermore, the adsorption base and the adsorption clamp are connected by a pipe thread.

[0054] Furthermore, the five-axis linkage machine tool includes: three linear motion units (X / Y / Z), a B-axis motion unit 1, and a C-axis motion unit 5. The horizontal X / Z-axis linear motion units are arranged perpendicularly to each other, and the vertical Y-axis linear motion unit is arranged on the X-axis linear motion unit guide rail. The B-axis motion unit 1 uses a hydrostatic bearing and is arranged on the Z-axis linear motion unit. The C-axis motion unit 5 uses a gas hydrostatic bearing and is mounted on the slide of the Y-axis linear motion unit. Both the B and C-axis motion units are driven by frameless torque motors and controlled by circular grating feedback. The milling axis 2 is offset and mounted on the B-axis motion unit 1 via a bushing. The ball end mill 3 is connected to the end of the milling axis 2 via a pneumatic clamping module. The thin-walled spherical shell workpiece 6 is adsorbed and connected to the end of the C-axis motion unit 5 via a vacuum adsorption fixture assembly. The high-resolution vertical CCD camera 4 is connected to the slide of the Y-axis linear motion unit for real-time monitoring and capture of the feature structure dimensions of the thin-walled spherical shell workpiece 6.

[0055] Furthermore, the processing device is equipped with a high-precision zero-point quick-change component for high-precision reversing and clamping of the microsphere target.

[0056] Compared with the prior art, the beneficial effects of the present invention are:

[0057] This invention discloses a method and apparatus for machining micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation. By generating point set coordinates, transforming spatial coordinates, and calibrating machining coordinates, the coordinates of the micro-pits with the center of the microsphere target as the origin are converted into programmable coordinates that can be read by the control system for CNC program writing. For five-axis linkage ultra-precision machining, the machining coordinate transformation enables high-precision, efficient, and controllable removal of micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells.

[0058] The device of this invention is equipped with a dedicated vacuum adsorption clamp assembly. The contact angle and contact area of ​​the clamp structure are optimized based on finite element simulation analysis to minimize the clamping deformation of complex micro-components with thin-walled spherical shells.

[0059] The method of this invention has a certain degree of universality. It is not only suitable for coordinate transformation in the machining of micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells of CH composite materials, but can also be further extended to the machining coordinate transformation in the machining of complex basic contour features of macro-scale parts on conventional multi-axis machine tools, thereby further ensuring machining accuracy and improving machining efficiency. Attached Figure Description

[0060] Figure 1 This is a flowchart of a method for fabricating micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation, as described in an embodiment of the present invention.

[0061] Figure 2 This is a schematic diagram of a device for processing micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells in an embodiment of the present invention;

[0062] Figure 3 This is a schematic diagram of the coordinate system for clamping and machining complex micro-components of thin-walled spherical shells in an embodiment of the present invention;

[0063] Figure 4 This is a schematic diagram of the coordinates of the set of points to be processed in an embodiment of the present invention (x wi <0,y wi >0);

[0064] Figure 5 This is a schematic diagram of the coordinates of the set of points to be processed in an embodiment of the present invention (x wi >0,y wi >0);

[0065] Figure 6 This is a schematic diagram of the coordinates of the set of points to be processed in an embodiment of the present invention (x wi >0,y wi <0);

[0066] Figure 7 This is a schematic diagram of the coordinates of the set of points to be processed in an embodiment of the present invention (x wi <0,y wi <0);

[0067] Figure 8 This is a schematic diagram of the rotation angle of axis B for the set of points to be processed in an embodiment of the present invention;

[0068] Figure 9 This is a schematic diagram of the X-axis coordinates of the set of points to be processed in an embodiment of the present invention;

[0069] Figure 10 This is a schematic diagram of the machining coordinate system in an embodiment of the present invention;

[0070] Figure 11 This is a diagram showing the relationship between the workpiece-fixture contact area and the diameter / radius of the microsphere target in an embodiment of the present invention;

[0071] Figure 12 This is a schematic diagram illustrating the process of optimizing the contact angle and contact area of ​​the workpiece-fixture contact using the finite element analysis method in an embodiment of the present invention.

[0072] Explanation of reference numerals in the attached figures:

[0073] 1-B-axis motion unit, 2-milling axis, 3-ball end mill, 4-vertical CCD camera, 5-C-axis motion unit, 6-workpiece. Detailed Implementation

[0074] In the description of this invention, it should be noted that the terms "first," "second," and "third" mentioned in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," and "third" may explicitly or implicitly include one or more of that feature.

[0075] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0076] Specific Implementation Plan 1: (e.g.) Figure 1 As shown, this invention provides a method for fabricating micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation, comprising the following steps:

[0077] S1. Point set coordinate generation: Adjust the high-resolution CCD camera to take pictures of the workpiece area, identify and obtain the diameter of the microsphere target, establish the workpiece coordinate system with the center of the microsphere target as the coordinate origin, and generate the initial coordinates of the micro-pit point set on the entire surface of the microsphere target.

[0078] S2. Spatial coordinate transformation: Based on the initial coordinates of the micro-pit point set on the entire surface of the micro-spherical target, the C-axis is rotated by a certain angle so that any micro-pit point to be processed on the surface of the micro-spherical target is rotated to the horizontal plane where the axis of the C-axis motion unit is located. The B-axis is rotated by a certain angle so that the angle between the milling axis and the Z-axis linear motion unit is equal to the angle between the line connecting the origin of the workpiece coordinate system and the direction of the Z-axis linear motion unit. Based on the coordinate transformation method, the coordinates of the B-axis and C-axis, as well as the coordinates of the X / Y / Z linear axis motion units in the workpiece coordinate system, are obtained.

[0079] S3. Machining coordinate calibration: Establish a machining coordinate system, and use coordinate transformation methods to convert the coordinates of the workpiece coordinate system into machining coordinates under the machining coordinate system to perform high-precision machining of the micro-pit structure.

[0080] Specific implementation plan two: S1 includes the following steps:

[0081] S1-1. Adjust the CCD camera to be parallel to the Y-axis so that it points to the microsphere target and is perpendicular to the horizontal plane, and obtain the image of the microsphere target. Obtain the maximum outer dimension of the microsphere target, i.e., the diameter of the microsphere target, through image processing.

[0082] The CCD camera is a 26-megapixel high-resolution industrial camera with a minimum image resolution of 1.25μm.

[0083] S1-2, as shown Figure 2 and Figure 3 As shown, the origin O is the center of the complex micro-spherical target. w With the negative direction of the Z-axis linear motion unit as Z... w +, with the positive direction of the X-axis linear motion unit as X w +, with the positive direction of the Y-axis linear motion unit as Y w +, Establish workpiece coordinate system O w -X w Y w Z w ;

[0084] S1-3. In the workpiece coordinate system, the number N of the micro-pit structures to be machined on the entire surface of the thin-walled microsphere target is... u The initial point set coordinates of the micro-pit structure on the entire surface of the microsphere target are generated based on the Fibonacci algorithm. This implementation scheme is otherwise identical to specific implementation scheme one.

[0085] In this embodiment, the workpiece coordinate system O w -X w Y w Z w The X / Y / Z linear motion units of the machining device are set up and remain stationary relative to the three linear motion units. During the subsequent C-axis rotation, the workpiece coordinate system remains stationary.

[0086] Specific Implementation Scheme 3: The initial point set coordinates of the micro-pit structure on the entire surface of the microsphere target generated by the Fibonacci algorithm as described in S1-3 are specifically as follows: along O w Z w The direction uniformly divides the microsphere target shell into N u If each layer has the same thickness, then the coordinate Z of the midpoint of the i-th layer in the thickness direction is... w for:

[0087]

[0088] D is the diameter of the microsphere target;

[0089] S1-4, by X w Xiang and Y wThe coordinates follow an arithmetic sequence distribution to ensure that X w and Y w The microstructure is relatively uniformly distributed, resulting in a micro-pit structure X on the surface of a thin-walled spherical shell. w Xiang and Y w To coordinates:

[0090]

[0091]

[0092] f represents the golden ratio. This implementation plan is otherwise the same as Implementation Plan Two.

[0093] Specific implementation plan four: In S1-3, the side surfaces of the segmented Nu layer are equivalent to toroidal surfaces, and the area of ​​each toroidal surface is πD. 2 / Nu ensures a uniform distribution of the micro-pit point set on a macroscopic scale. This implementation scheme is otherwise identical to specific implementation scheme three.

[0094] Specific implementation plan five: S2 includes the following steps:

[0095] S2-1, The workpiece coordinate system contains any point N to be machined. i coordinates (x) wi ,y wi ,z wi ), to X w O w Y w Projecting the image onto the plane yields the projection point Pi. Based on the angle εi between the line connecting the projection point Pi and the origin Ow of the workpiece coordinate system and the Yw axis, the machining point N is obtained through coordinate transformation. i The corresponding C-axis coordinate;

[0096] Specifically, such as Figure 4 As shown, when any point N to be processed i (x wi ,y wi Located in X w O w Y w The second quadrant of the coordinate system, i.e., x wi If <0, ywi>0, then the C-axis rotation angle corresponding to the point Ni to be processed is (π / 2-εi), and the corresponding C-axis coordinate is:

[0097]

[0098] like Figure 5 As shown, when any point N to be processed i (x wi ,y wi Located in X w Ow Y w The first quadrant of the coordinate system, i.e., x wi >0,y wi If the value is greater than 0, then the C-axis rotation angle corresponding to the point Ni to be processed is (π / 2 + εi), and the corresponding C-axis coordinate is:

[0099]

[0100] like Figure 6 As shown, when any point N to be processed i (x wi ,y wi Located in X w O w Y w The fourth quadrant of the coordinate system, i.e., x wi >0,y wi <0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is The corresponding C-axis coordinate is:

[0101]

[0102] like Figure 7 As shown, when any point N to be processed i (x wi ,y wi Located in X w O w Y w The third quadrant of the coordinate system, i.e., x wi <0,y wi <0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is The corresponding C-axis coordinate is:

[0103]

[0104] Workpiece coordinate system X w O w Z w The zero point of the C-axis is when it is parallel to the plane containing the linear motion units of the X and Z axes of the equipment.

[0105] Along the workpiece coordinate system Z w The C-axis rotates clockwise with a positive angle and counterclockwise with a negative angle.

[0106] S2-2, as shown Figure 8 As shown, from any point N to be machined in the workpiece coordinate system i (x wi ,y wi ,z wi ), connection point Ni With the center of the microsphere target O w denoted as N i O w According to N i O w With respect to the workpiece coordinate system Z w Positive axial angle β i The machining point N is obtained through coordinate transformation. i The corresponding B-axis coordinate is:

[0107]

[0108] Any point N to be processed i The corresponding N i O w With respect to the workpiece coordinate system Z w The positive included angle of the axis is equal to the rotation angle of its corresponding B-axis during machining;

[0109] Along the workpiece coordinate system Y w The B-axis is defined as the negative direction, with the clockwise direction of the B-axis being the positive direction.

[0110] S2-3, as shown Figure 9 As shown, any point N to be machined in the workpiece coordinate system i (x wi ,y wi ,z wi Rotation of C axis i After adjusting the angle, rotate to the workpiece coordinate system X. w O w Z w In the plane, and at the origin O of the machining coordinate system w Connecting lines and Z w The positive angle is B i Then to X w O w Y w Its projection in the plane, on O w X w - The projection point is denoted as H. i Then O w H i That is, the point N to be processed. i Corresponding X w coordinate X wi From the coordinate transformation relationship, we get:

[0111]

[0112] C-axis rotation angle C i After that, N i O w With respect to the workpiece coordinate system Z w Positive axial angle β i Remain unchanged;

[0113] C-axis rotation angle C i Then, any point N to be processed i Z i The coordinates remain unchanged.

[0114] S2-4. Any point N to be machined in the workpiece coordinate system i (x wi ,y wi ,z wi Rotation of C axis i After adjusting the angle, rotate to X. w O w Z w In the plane, its Y w coordinate Y wi =0; Rotate B axis i After the angle, its Z w With the coordinates remaining unchanged, we can see from formula (1):

[0115]

[0116] Obtain any point N to be machined in the workpiece coordinate system i Machining coordinates (X) wi ,Y wi Z wi B wi C wi This implementation plan is otherwise the same as that of Specific Implementation Plan Three.

[0117] Specific implementation plan six: S3 includes the following steps:

[0118] S3-1, Control the X / Y / Z linear motion unit to perform tool setting operation;

[0119] The tool setting is completed by observing the workpiece-tool contact area with a high-resolution CCD camera to determine whether there are trace chips. The positioning accuracy of the X / Y / Z axis linear motion unit is better than 0.4μm / full stroke.

[0120] S3-2, such as Figure 10 As shown, the tool setting completion point is set as the machining origin, and also as the origin O of the machining coordinate system. m With the positive direction of the Z-axis linear motion unit as Z... m +, with the positive direction of the X-axis linear motion unit as X m +, with the positive direction of the Y-axis linear motion unit as Y m +, Establish machining coordinate system O m -X m Y m Z m ;

[0121] S3-3. Based on the coordinate transformation method, any micro-pit point N to be machined in the workpiece coordinate system is transformed. i (X wi ,Y wi Z wi B wi C wi Convert to machining coordinates N in the machining coordinate system i (X i ,Y i Z i B i C i );

[0122] Any micro-pit point N to be processed i (X i ,Y i Z i B i C i In the machining coordinate system, X m Y m and Z m The coordinates of the directions are as follows:

[0123]

[0124] Y i =Y wi =0 (12)

[0125]

[0126] Any micro-pit point N to be processed i (X i ,Y i Z i B i C i In the machining coordinate system, B i The coordinates are:

[0127]

[0128] Any micro-pit point N to be processed i (X i ,Y i Z i B i C i In the machining coordinate system, C i The coordinates are:

[0129]

[0130] After completing the spatial transformation of the coordinates of the micro-pit structures on the entire surface of the complex micro-component of the thin-walled spherical shell, the micro-pit structures are machined according to the machining coordinates. The rest of this implementation scheme is the same as specific implementation scheme five.

[0131] For the machining of the remaining hemispherical surface microstructure, a high-precision turning and clamping is achieved by a zero-point quick-change component. The spatial coordinates of the spherical shell surface feature structure are extracted by a high-resolution CCD camera. Based on the same method described above, the transformation of the remaining point set coordinate system and the acquisition of machining coordinates are realized, thereby completing the machining of the full surface microstructure.

[0132] Specific Implementation Scheme Seven: A processing device for micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells, characterized in that the processing device is a five-axis linkage machine tool, including a vacuum adsorption fixture assembly, the vacuum adsorption fixture assembly including a hollow adsorption base and an adsorption chuck, the end of the adsorption chuck is trumpet-shaped, used for adsorbing workpieces by vacuum, the inclined side of the end section of the adsorption chuck forms an angle of 35° to 46° with the central axis, and the ratio of the inner diameter of the port of the adsorption chuck used for adsorbing workpieces to the diameter of the target ball to be processed is (0.6 to 0.8):1.

[0133] Specific implementation scheme eight: The adsorption base and the adsorption clamp are connected by a pipe thread. All other aspects of this implementation scheme are the same as specific implementation scheme seven.

[0134] Specific Implementation Scheme Nine: The five-axis linkage machine tool includes: three linear motion units (X / Y / Z), a B-axis motion unit 1, and a C-axis motion unit 5. The horizontal X / Z-axis linear motion units are arranged perpendicularly to each other, and the vertical Y-axis linear motion unit is arranged on the X-axis linear motion unit guide rail. The B-axis motion unit 1 uses a hydrostatic bearing and is arranged on the Z-axis linear motion unit. The C-axis motion unit 5 uses a gas hydrostatic bearing and is mounted on the slide of the Y-axis linear motion unit. Both the B and C-axis motion units are driven by frameless torque motors and controlled by circular grating feedback. The milling axis 2 is offset and mounted on the B-axis motion unit 1 via a bushing. The ball end mill 3 is connected to the end of the milling axis 2 via a pneumatic clamping module. The thin-walled spherical shell workpiece 6 is adsorbed and connected to the end of the C-axis motion unit 5 via a vacuum adsorption fixture assembly. A high-resolution vertical CCD camera 4 is connected to the slide of the Y-axis linear motion unit for real-time monitoring and capture of the characteristic structural dimensions of the thin-walled spherical shell workpiece 6. Other aspects of this implementation scheme are the same as in Specific Implementation Scheme Seven.

[0135] Specific Implementation Scheme Ten: The processing device is equipped with a high-precision zero-point quick-change component for high-precision reversing and clamping of the microsphere target. All other aspects of this implementation scheme are the same as Specific Implementation Scheme Nine.

[0136] The zero-point quick-change component in this implementation scheme is an application of existing technology and will not be explained in detail here. The repeatability of the zero-point quick-change component is ±0.5μm. It is used for turning and clamping the microsphere target to realize the conversion of the machining coordinates and high-precision machining of the 20 micro-pit structures on the entire surface of the complex micro-components made of CH material thin-walled spherical shell with diameter of 1-5mm and wall thickness of 20-120μm.

[0137] Example 1

[0138] The method of the present invention will be described using the following specific embodiments.

[0139] S1 Midpoint Set Coordinate Generation: Adjust the high-resolution CCD camera to photograph the workpiece area, identify and obtain the microsphere target diameter. The microsphere target is clamped by a dedicated vacuum adsorption fixture assembly, and the microsphere target diameter D = 1.000 mm is obtained. Establish the workpiece coordinate system O with the center of the microsphere target as the origin. w -X w Y w Z w ;

[0140] The number N of micro-pit structures on the entire surface of the microsphere target u =20, based on the Fibonacci algorithm and X w and Y w The initial coordinates of the set of 20 micro-pit structure points on the entire surface of the microsphere target in the workpiece coordinate system were obtained by arithmetic sequence distribution, as shown in Table 1.

[0141] Table 1

[0142]

[0143] S2, by N u = Coordinates of 20 micro-pit points, directed towards X w O w Y w Projecting in the plane, obtaining the line connecting the projection point and the origin of the workpiece coordinate system, and the Y-axis. w The included angles of the axes and the corresponding C-axis coordinates are shown in Table 2:

[0144] Table 2

[0145]

[0146] By N u =20 micro-pit point coordinates and microsphere target diameter D = 1.000 mm, obtain N i O w With respect to the workpiece coordinate system Z w The positive included angle βi and the B-axis coordinates corresponding to the point set Ni are shown in Table 3:

[0147] Table 3

[0148]

[0149] N in the workpiece coordinate system u = 20 micro-pit point sets rotated C along the C-axis i After the angle, further towards X w O w Y w Projecting onto the plane to obtain the set N of micro-pits to be processed. i Corresponding X w coordinate X wi ; The point set N in the workpiece coordinate system i Rotation of C-axis i After adjusting the angle, rotate to X. w O w Z w In the plane, its Y w coordinate Y wi =0; and any point set N i Rotation of C along the C-axis i Angle, rotation along axis B i After the angle, its Z w With the coordinates remaining unchanged, the X / Y / Z axis coordinates of the micro-pit point set in the workpiece coordinate system are shown in Table 4:

[0150] Table 4

[0151]

[0152] For Z w The set of micro-pit points <0 is used for reversing and clamping by a high-precision zero-point quick-change component. w This transforms into -Z w This allows for the fabrication of microstructures across the entire surface.

[0153] S3. The program controls the movement of each axis to achieve precise tool setting. The point where the tool setting is completed is defined as the machining origin, and this is used as the origin O of the machining coordinate system. m Based on the coordinate transformation method, the machining coordinates under the above workpiece coordinate system are transformed to the machining coordinate system, resulting in N in the machining coordinate system. i Point set coordinates (X) i ,Y i Z i B i C i As shown in Table 5:

[0154] Table 5

[0155]

[0156]

[0157] The above steps enable efficient spatial transformation of the coordinates of 20 micro-pit structures on the entire surface of a complex, thin-walled spherical shell component. The coordinates are transformed from the workpiece coordinate system to the machining coordinate system for use in the CNC program of the control system, achieving high-precision, efficient, and controllable removal of the micro-pit structures.

[0158] Example 2

[0159] The processing apparatus of the present invention will be described using the following specific embodiments.

[0160] The microsphere target is adsorbed onto the vacuum adsorption fixture by negative pressure, and a seal is achieved between the microsphere target and the fixture clamp through circumferential contact. Figure 11 As shown, when the radius of the microsphere target is R, the corresponding contact circumference radius is R*cosα, and the workpiece-fixture contact area S = π*(R*cosα) 2 , where α is the contact angle, and its value ranges from 35° to 46° after optimization using the finite element method.

[0161] like Figure 12 As shown, the deformation of the microsphere target during workpiece clamping and workpiece-fixture adsorption contact (circumferential contact) was simulated using the finite element analysis method to optimize the contact angle and contact area, and further optimize the fixture structure.

[0162] Specifically, when the diameter of the microsphere target is 1 mm, the optimized contact angle is 37°, and the workpiece-fixture adsorption contact area S = π*(0.5*cos37°) 2 =0.5. Based on finite element simulation, the maximum static deformation of the microsphere target at the circumferential contact point is only 9.26 nm, which meets the actual processing requirements.

[0163] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for machining micro-pit structures on the surface of complex micro-components of thin-walled spherical shells based on coordinate transformation, wherein the method is implemented using a machining device for micro-pit structures on the surface of complex micro-components of thin-walled spherical shells, the machining device being a five-axis linkage machine tool, including a vacuum adsorption fixture assembly, the vacuum adsorption fixture assembly including a hollow adsorption base and an adsorption chuck, the end of the adsorption chuck being trumpet-shaped for adsorbing workpieces by vacuum, the inclined side of the end section of the adsorption chuck forming an angle of 35°~46° with the central axis, and the ratio of the inner diameter of the port of the adsorption chuck used for adsorbing the workpiece to the diameter of the target sphere to be machined being (0.6~0.8):1; the five-axis linkage machine tool includes: The X / Y / Z linear motion units, B-axis motion unit (1), and C-axis motion unit (5) are arranged perpendicularly to each other. The vertical Y-axis linear motion unit is arranged on the X-axis linear motion unit guide rail. The B-axis motion unit (1) uses a liquid hydrostatic bearing and is arranged on the Z-axis linear motion unit. The C-axis motion unit (5) uses a gas hydrostatic bearing and is installed on the slide of the Y-axis linear motion unit. The B / C-axis motion units are driven by frameless torque motors and controlled by circular grating feedback. The milling axis (2) is installed on the B-axis motion unit (1) by a bushing offset. The ball end mill (3) is connected to the end of the milling axis (2) via a pneumatic clamping module. The thin-walled spherical shell workpiece (6) is attached to the end of the C-axis motion unit (5) by a vacuum adsorption fixture assembly. The high-resolution vertical CCD camera (4) is connected to the slide of the Y-axis linear motion unit for real-time monitoring and capture of the feature structure dimensions of the thin-walled spherical shell workpiece (6). Its features include the following steps: S1. Point set coordinate generation: By observing with a high-resolution CCD camera, the axis of the C-axis motion unit and the axis of the milling axis are in the same plane. The high-resolution CCD camera is adjusted to take pictures of the workpiece area, the diameter of the microsphere target is identified and obtained, and the workpiece coordinate system is established with the center of the microsphere target as the coordinate origin to generate the initial coordinates of the micro-pit point set on the entire surface of the microsphere target. S2. Spatial coordinate transformation: Based on the initial coordinates of the micro-pit point set on the entire surface of the micro-spherical target, the C-axis is rotated by a certain angle so that any micro-pit point to be processed on the surface of the micro-spherical target is rotated to the horizontal plane where the axis of the C-axis motion unit is located. The B-axis is rotated by a certain angle so that the angle between the milling axis and the Z-axis linear motion unit is equal to the angle between the line connecting the origin of the workpiece coordinate system and the direction of the Z-axis linear motion unit. The coordinates of the B-axis and C-axis, as well as the coordinates of the X / Y / Z linear axis motion units in the workpiece coordinate system, are obtained. S3. Machining coordinate calibration: Establish a machining coordinate system, convert the coordinates of the workpiece coordinate system into machining coordinates under the machining coordinate system, and perform high-precision machining on the micro-pit structure; S1 includes the following steps: S1-1. Adjust the CCD camera to point at the microsphere target and perpendicular to the horizontal plane to obtain an image of the microsphere target. Obtain the maximum outer dimension of the microsphere target, i.e., the diameter of the microsphere target, through image processing. S1-2, with the center of the complex micro-spherical target as the origin O. w With the negative direction of the Z-axis linear motion unit as Z... w +, with the positive direction of the X-axis linear motion unit as X w +, with the positive direction of the Y-axis linear motion unit as Y w +, Establish workpiece coordinate system O w -X w Y w Z w； S1-3. In the workpiece coordinate system, the number N of the micro-pit structures to be machined on the entire surface of the thin-walled microsphere target is... u The initial point set coordinates of the micro-pit structure on the entire surface of the microsphere target were generated based on the Fibonacci algorithm. The initial point set coordinates for generating the full-surface micro-pit structure of the microsphere target based on the Fibonacci algorithm described in S1-3 are specifically as follows: along O w Z w The direction uniformly divides the microsphere target shell into N u If the i-th layer is a shell, then the coordinate of the midpoint Z in the thickness direction of the i-th layer is... w for: (1) D is the diameter of the microsphere target; S1-4, by X w Xiang and Y w The coordinates follow an arithmetic sequence distribution, yielding the micro-pit structure X on the surface of the thin-walled spherical shell. w Xiang and Y w To coordinates: (2) (3) f represents the golden ratio; S2 includes the following steps: S2-1, The workpiece coordinate system contains any point N to be machined. i coordinates (x) wi , y wi , z wi ), to X w O w Y w Projecting onto the plane yields the projection point P. i Based on projection point P i and the origin O of the workpiece coordinate system w Connect the line and Y w axial angle ε i The processing point N is obtained. i The corresponding C-axis coordinate; Specifically, when any point N to be processed i (x wi , y wi Located in X w O w Y w The second quadrant of the coordinate system, i.e., x wi <0, y wi >0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is ( / 2-ε i If ), then the corresponding C-axis coordinate is: (4) When any point N to be processed i (x wi , y wi Located in X w O w Y w The first quadrant of the coordinate system, i.e., x wi >0, y wi >0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is ( / 2+ε i If ), then the corresponding C-axis coordinate is: (5) When any point N to be processed i (x wi , y wi Located in X w O w Y w The fourth quadrant of the coordinate system, i.e., x wi >0, y wi <0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is The corresponding C-axis coordinate is: (6) When any point N to be processed i (x wi , y wi Located in X w O w Y w The third quadrant of the coordinate system, i.e., x wi <0, y wi <0, at this time the point N to be processed is... i The corresponding C-axis rotation angle is The corresponding C-axis coordinate is: (7) S2-2, From any point N to be processed in the workpiece coordinate system i (x wi , y wi , z wi ), connection point N i With the center of the microsphere target O w denoted as N i O w According to N i O w With respect to the workpiece coordinate system Z w Positive axial angle β i The processing point N is obtained. i The corresponding B-axis coordinate is: (8) S2-3, Any point N to be machined in the workpiece coordinate system i (x wi , y wi , z wi Rotation of C axis i After adjusting the angle, rotate to the workpiece coordinate system X. w O w Z w In the plane, and at the origin O of the machining coordinate system w Connecting lines and Z w The positive angle is B i Then to X w O w Y w Its projection in the plane, on O w X w - The projection point is denoted as H. i Then O w H i That is, the point N to be processed. i Corresponding X w coordinate X wi From the coordinate transformation relationship, we get: (9) S2-4. Any point N to be machined in the workpiece coordinate system i (x wi , y wi , z wi Rotation of C axis i After adjusting the angle, rotate to X. w O w Z w In the plane, its Y w coordinate Y wi =0; Rotate B axis B i After the angle, its Z w With the coordinates remaining unchanged, we can see from formula (1): (10) S3 includes the following steps: S3-1, Control the X / Y / Z linear motion unit to perform tool setting operation; S3-2. Set the tool setting completion point as the machining origin and set it as the origin O of the machining coordinate system. m With the positive direction of the Z-axis linear motion unit as Z... m +, with the positive direction of the X-axis linear motion unit as X m +, with the positive direction of the Y-axis linear motion unit as Y m +, Establish machining coordinate system O m -X m Y m Z m ; S3-3, Place any micro-pit point N to be machined in the workpiece coordinate system. i (X wi Y wi Z wi B wi C wi Convert to machining coordinates N in the machining coordinate system i (X i Y i Z i B i C i ); Any micro-pit point N to be processed i (X i Y i Z i B i C i In the machining coordinate system, X m Y m and Z m The coordinates of the directions are as follows: (11) AND i =Y wi =0 (12) (13) Any micro-pit point N to be processed i (X i Y i Z i B i C i In the machining coordinate system, B i The coordinates are: (14) Any micro-pit point N to be processed i (X i Y i Z i B i C i In the machining coordinate system, C i The coordinates are: (15) After completing the spatial transformation of the coordinates of the micro-pit structures on the entire surface of the complex micro-component of the thin-walled spherical shell, the micro-pit structures are processed according to the processing coordinates.

2. The method for fabricating micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation according to claim 1, characterized in that, In S1-3, the N segments are divided into u The side surface of the layer is equivalent to a torus, and the area of ​​each torus is equal to 1. D 2 / N u This ensures the uniform distribution of the micro-pit point set on a macroscopic scale.

3. The method for fabricating micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation according to claim 1, characterized in that, The adsorption base and the adsorption clamp are connected by a pipe thread.

4. The method for processing micro-pit structures on the surface of complex micro-components such as thin-walled spherical shells based on coordinate transformation according to claim 3, characterized in that, The processing device is equipped with a high-precision zero-point quick-change component for high-precision turning and clamping of microsphere targets.

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