A method of co-body processing of multi-surface devices

Abstract

This invention discloses a method for the integrated machining of multi-surface devices, relating to the field of ultra-precision machining technology. The method includes: obtaining the rotation angle range of the rotating shaft based on the multi-surface device to be machined; obtaining the tool position using the rotation angle range; performing path planning based on the parameters of the multi-surface device, the cutting radius of the diamond tool, and the tool position to obtain a linkage machining path; obtaining the actual radius of the cutting edge of the tool using the linkage machining path; generating a target machining path based on the actual radius of the cutting edge, the parameters of the multi-surface device, and the tool position; and machining the multi-surface device to be machined using the target machining path to achieve integrated machining of the multi-surface device. This invention solves the problem of different radii of different cutting edge regions of the tool during tool rotation and cutting, and by compensating for and correcting this error, the integrated machining method using different cutting edge regions of the diamond tool during XZB axis linkage achieves integrated machining of devices with multiple surfaces.

Description

Technical Field

[0001] This invention belongs to the field of ultra-precision machining technology, and specifically relates to a method for co-processing multi-surface devices. Background Technology

[0002] Multi-surface devices have a wide range of applications, especially multi-surface optical elements in the field of optics, such as multi-reflective optical systems with multiple reflective surfaces and mirrors formed by multiple surfaces. These multi-surface devices not only require high surface accuracy for each surface, but also require high accuracy in the relative position and orientation between different surfaces. Otherwise, it will affect the installation error, optical performance and other application effects of such devices.

[0003] Generally, multi-surface device machining employs a split-cutting method, where the device is repositioned and re-clamped onto the machine tool while machining each surface. In this approach, the poses between different surfaces are adjusted using only tool setting or positioning blocks, a process whose accuracy is often difficult to guarantee. Integrated machining, on the other hand, can machine multiple surfaces without moving the device itself, by rotating it. The relative poses of the different surfaces are maintained by the machine tool spindle. However, current integrated machining methods only use the spindle to adjust the pose of the machined surface, without rotating the spindle during cutting. This limitation, due to the finite cutting edge of the diamond tool, restricts the machined area and surface curvature. Especially when machining some compact multi-surface devices, it is impossible to generate a collision-free machining path without rotating the tool.

[0004] Therefore, there is an urgent need for a co-processing method for multi-surface devices to address the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to propose a method for the co-processing of multi-surface devices, so as to realize the co-processing of multi-surface devices.

[0006] To achieve the above objectives, the present invention provides a method for the co-processing of multi-surface devices, comprising the following steps:

[0007] The rotation angle range of the shaft is obtained based on the multi-surface device to be processed;

[0008] The tool position is obtained using the angular range of the rotation of the shaft.

[0009] A linkage machining path is obtained by path planning based on the parameters of the multi-surface device, the cutting radius of the diamond tool, and the tool position.

[0010] The actual radius of the tool cutting edge is obtained using the aforementioned linkage machining path;

[0011] A target machining path is generated based on the actual radius of the cutting edge, the parameters of the multi-surface device, and the position of the cutting tool;

[0012] The multi-surface device to be processed is processed using the target processing path to achieve the co-processing of the multi-surface device.

[0013] Optionally, the range of rotation angles of the shaft can be obtained based on the multi-surface device to be processed, including:

[0014] The position and orientation of the diamond tool are obtained by fixing the tool post on the machine tool spindle;

[0015] The angle range of the shaft rotation is obtained by adjusting the position and orientation of the diamond tool so that the contact position between the diamond tool and the processing surface of the multi-surface device to be processed is in the cutting edge area.

[0016] Optionally, obtaining the tool position using the angular range of the rotation of the shaft includes:

[0017] Based on the angle range of the rotation of the shaft, the rotation of the shaft is controlled, and the machine tool position is obtained by using a tool setting device to make the diamond tool contact the tool setting block;

[0018] The tool position is obtained using an optimization function based on the machine tool position.

[0019] Optionally, the optimization function is:

[0020] [L,D]=arc min||LL cos(θ i )+D sin(θ i )+(Z i -Z0)||

[0021] Where L is the component of the distance between the center of the diamond tool arc and the center of the rotation axis along the Z-axis, D is the component of the distance between the center of the diamond tool arc and the center of the rotation axis along the X-axis, arcmin‖·‖ is the value of L and D that minimizes ·, and θ i Let i be the rotation angle of the spindle, i = 1, 2, 3, 4, 5, and (X0, Z0) be the position of the machine tool when the arc-shaped contour of the diamond tool tip touches the tool setting block when the spindle is at 0°. i Z i ) is the rotation of the axis to θ i When the arc-shaped contour of the tip of the diamond tool touches the tool block, the position of the machine tool is reached.

[0022] Optionally, the path planning to obtain the linkage machining path based on the multi-surface device parameters, the diamond tool cutting edge radius, and the tool position includes:

[0023] The sampling points for the multi-surface device parameters are obtained based on the multi-surface device parameters.

[0024] The coordinates of the sampling points corresponding to the multi-surface device parameter sampling points are obtained based on the KD tree using the sampling points of the multi-surface device parameter sampling points;

[0025] The normal vector at the sampling point is calculated by using the coordinates of the sampling points corresponding to the sampling points of the multi-surface device parameters through plane fitting.

[0026] Calculate the center coordinates of the cutting edge of the diamond tool based on the normal vector at the sampling point and the cutting edge radius of the diamond tool.

[0027] The rotation angles corresponding to the multi-surface device parameter sampling points are obtained by uniformly distributing the rotation angle range of the shaft.

[0028] The target motion is calculated by combining the center coordinates of the cutting edge of the tool with the rotation axis angle corresponding to the sampling points of the multi-surface device parameters and the tool position.

[0029] The linkage processing path is obtained based on the target motion amount.

[0030] Optionally, the coordinates of the tool cutting edge center are calculated as follows:

[0031] X c =x n +R(θ n )*V x

[0032] Z c =z n +R(θ n )*V z

[0033] Among them, (X) c Z c (x) represents the coordinates of the center of the cutting edge of the tool. n ,z n ) represents the sampling point, R(θ) n (V) represents the cutting edge radius of the diamond tool. x V z ) represents the normal vector at the sampling point.

[0034] Optionally, the rotation angle at each sampling point is:

[0035] θ n =α1+(x n -x n_min (α1-α2) / (x n_min -x n_max )

[0036] Where, θ nLet x be the rotation angle at each sampling point, [α1, α2] be the range of rotation angles of the rotation axis during the machining process, and x be the rotation angle at each sampling point. n_min x n_max These represent the minimum and maximum position coordinates of the X-axis guide rail during the machining process.

[0037] Optionally, the target exercise volume is:

[0038] X n =X c +L sin(θ n )-Dcos(θ n )

[0039] Z n =Z c +L cos(θ n )+Dsin(θ n )

[0040] Among them, X n The corresponding motion along the X-axis, Z n Let L be the Z-axis motion, D be the Z-axis component of the distance between the center of the diamond tool arc and the center of the rotation axis, and θ be the X-axis component of the distance between the center of the diamond tool arc and the center of the rotation axis. n The rotation angle at each sampling point.

[0041] Optionally, obtaining the actual radius of the tool cutting edge using the linked machining path includes:

[0042] The cutting surface shape is obtained using a contour measuring device based on the aforementioned linkage machining path;

[0043] The actual radius deviation is calculated using the cutting surface shape.

[0044] The actual radius at the cutting edge of the tool is obtained based on the actual radius deviation and the ideal cutting edge radius of the tool.

[0045] The angle of the rotating shaft at the sampling point on the axial surface is obtained by utilizing the angular range of the rotating shaft.

[0046] The actual radius of the tool cutting edge is obtained by substituting the rotation angle corresponding to the sampling point on the off-axis surface into the actual radius curve at the tool cutting edge.

[0047] Optionally, the actual radius at different cutting edges of the tool is:

[0048] R(θ)=e(θ)+r

[0049] Where R(θ) is the actual radius at different cutting edges of the tool, e(θ) is the relationship curve between the rotation axis angle θ and the actual radius deviation e at different cutting edges of the tool, and r is the ideal cutting edge radius of the tool.

[0050] Compared with the closest existing technology, the present invention has the following advantages:

[0051] The method for machining multiple surface devices using this invention avoids problems such as insufficient cutting edge or collisions in the machining path when the tool is not rotating. When the tool rotates, if the position of the tool relative to the axis of rotation is not calibrated, a high-precision machining path cannot be generated. This invention achieves high-precision calibration without trial cutting by optimizing the tool block contact. This invention solves the problem of different radii of different cutting edge regions of the tool when the tool rotates and cuts, and corrects this error through compensation. This invention uses a method for machining different cutting edge regions of a diamond tool when XZB axis linkage, which can realize the machining and forming of multiple surface devices. Attached Figure Description

[0052] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0053] Figure 1 This is a flowchart illustrating a method for the co-processing of multi-surface devices according to an embodiment of the present invention;

[0054] Figure 2 This is a schematic diagram of the two-reflection system to be processed according to an embodiment of the present invention;

[0055] Figure 3 This is a structural diagram of the integrated machining center proposed in an embodiment of the present invention;

[0056] Figure 4 This is a schematic diagram of the tool position calibration proposed in an embodiment of the present invention. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0058] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0059] Example 1

[0060] like Figure 1 As shown, the present invention provides a method for the co-processing of multi-surface devices, comprising the following steps:

[0061] S1. Collision test: First, install the multi-surface device to be processed on the spindle of the machine tool. Fix the tool post on the machine tool spindle and adjust the position and posture of the diamond tool so that when the multi-axis linkage cuts each surface, the contact position between the diamond tool and the processing surface of the multi-surface device to be processed is in the cutting edge area and no collision occurs throughout the process. Record the rotation angle range [α1, α2] of the spindle during the processing.

[0062] S2. Tool position calibration: Assuming that when the axis angle is 0°, the distance between the center of the diamond tool arc and the center of the axis is D and L in the X-axis and Z-axis directions, respectively;

[0063] A tool setting block is fixed on the spindle. Based on the angle range [α1, α2] that the spindle can rotate when machining each surface, the spindle is controlled to rotate at multiple angles. A diamond tool is used to contact the tool setting block with a tool setting device, and the position of each axis of the machine tool is recorded. Based on these machine tool positions, D and L are calculated by an optimization function.

[0064] S3. Linked Machining Path Generation: The linked machining path is calculated based on the multi-surface device parameters, machine tool parameters such as the diamond tool cutting edge radius, and tool position parameters D and L. The multi-surface device parameters are the equations and parameters of each face of the multi-surface device being machined, provided by the machining party and are known information. Specifically, the initial linked machining path is calculated as follows:

[0065] First, the B-axis angle is assigned, and multiple sampling points (x) are generated at certain intervals based on the parameters of the multi-surface device. n ,z n Then, a KD-tree is used to search for the coordinates of several nearby sampling points for each sampling point; the normal vector (V) at the sampling point is calculated by plane fitting using the coordinates of the several nearby sampling points. x V z ); based on the normal vector (V) at the sampling point x V z ) and diamond tool cutting edge radius R(θ) n Calculate the coordinates of the center of the cutting edge (X). c Z c ):

[0066] X c =x n +R(θ n )*V x

[0067] Zc =z n +R(θ n )*V z

[0068] Then, based on the rotation angle range [α1, α2] of the rotating shaft determined in Example S1, within the diameter range [x] along the X direction... n_min ,x n_max The rotation angle θ at each sampling point is evenly distributed between α1 and α2. n :

[0069] θ n =α1+(x n -x n_min (α1-α2) / (x n_min -x n_max )

[0070] Finally, based on the coordinates of the tool cutting edge center (X... c Z c and the rotation angle θ at each sampling point n And combine L and D to calculate the target motion, that is, the corresponding motion X on the X and Z axes. n and Z n :

[0071] X n =X c +Lsin(θ n )-D cos(θ n )

[0072] Z n =Z c +Lcos(θ n )+D sin(θ n )

[0073] Where, x n_min x n_max These represent the minimum and maximum position coordinates of the X-axis guide rail during the machining process.

[0074] Therefore, the linkage machining path can be represented as the machine tool coordinates (X, X) at a series of sampling points. n Z n ,θ n The calculation has been completed.

[0075] S4. Diamond tool cutting edge radius compensation: A plane is machined according to the initial machining path in Example 1, S3. The surface shape after machining is measured using a contour measuring device or a surface shape measuring device. Since the rotation axis angle is different at different positions during machining, the tool cutting edge area is different. Therefore, the actual radius at different cutting edge positions of the tool is calculated based on the measurement results to obtain the correspondence between the rotation axis angle and the actual radius.

[0076] Based on the parameters of the multi-surface device, the coordinates of multiple sampling points near each sampling point are searched by KD tree. Then, the plane is fitted and the normal vector at the sampling point is calculated. Similar to S3 in Example 1, the angles are evenly distributed within the range of [α1, α2] that the rotation axis of each surface in the multi-surface device to be processed can rotate, so as to obtain the rotation axis angle corresponding to each sampling point on the off-axis surface.

[0077] S5. Formal Cutting: For the device to be processed, the linkage processing path of each surface is generated using the method in S3 of Example 1. At this time, the diamond tool cutting radius is calculated using the rotation axis angle at each sampling point and the corresponding relationship obtained in S4 of Example 1.

[0078] Example 2

[0079] like Figure 2 As shown, taking the donor cutting process of a dual-reflection system with two off-axis parabolic surfaces as an example, a method for co-processing multi-surface devices is provided. The detailed implementation process is as follows:

[0080] Step 1, such as Figure 3 As shown, the blank of the two-dimensional optical system to be processed is mounted on the spindle of the machining tool. The tool post is fixed on the B-axis of the machine tool, and the position and posture of the diamond tool are adjusted so that when the two surfaces are cut by multi-axis linkage, the contact position between the diamond tool and the surface of the two-dimensional optical system to be processed is in the cutting edge area, and no collision occurs throughout the process. Then, the range of angles that the axis can rotate when processing each surface is recorded. The angles that the B-axis can rotate for the two surfaces are 20-25° and 40-60°, respectively.

[0081] Step 2: Fix the tool setting block on the spindle. Control the rotation of the spindle to 5 angles according to the rotatable angles of the B-axis on the two surfaces. Observe in the field of view of the machine tool tool setting instrument. When the arc-shaped contour of the tip of the diamond tool is tangent to the plane contour of the tool setting block, record the position of the machine tool's Z-axis movement. The detailed implementation process is as follows:

[0082] like Figure 4 As shown, assuming the B-axis (i.e., the rotation axis) is 0°, the tool position when touching the tool setting block is (X0, Z0), and the B-axis (i.e., the rotation axis) rotates to θ... i (i = 1, 2, 3, 4, 5), the machine tool positions when the tool setting block is touched are (X)i Z i Based on these machine tool positions, D and L are calculated using an optimization function, which is:

[0083] [L,D]=arc min||LL cos(θ i )+Dsin(θ i )+(Z i -Z0)||

[0084] Where L is the component of the distance between the center of the diamond tool arc and the center of the rotation axis along the Z-axis, D is the component of the distance between the center of the diamond tool arc and the center of the rotation axis along the X-axis, arcmin||·|| is the value of L and D that minimizes ·, and θ i Let i be the rotation angle of the spindle, i = 1, 2, 3, 4, 5, and (X0, Z0) be the position of the machine tool when the arc-shaped contour of the diamond tool tip touches the tool setting block when the spindle is at 0°. i Z i ) is the rotation of the axis to θ i When the arc-shaped contour of the tip of the diamond tool touches the tool block, the position of the machine tool is reached.

[0085] Step 3: Generate two XZB linked planar machining paths. To ensure that the B-axis angle range covers the two parabolic angle ranges in Step 1, the angle ranges used for these two paths are 15–30° and 35–65°, respectively. The radii of the two circular diameter planes to be machined are 10 mm and 20 mm, respectively. The sampling points are generated at 10 μm intervals in the XOZ plane. By linearly and uniformly distributing 15–30° within a 10 mm diameter and 35–65° within a 20 mm diameter, the coordinates (x, z) of each sampling point and the corresponding rotation axis (i.e., B-axis) angle θ can be calculated. Finally, the linked machining path is generated and cutting is performed according to the calculation method in Example 1, S3.

[0086] The surface shape after cutting is measured using a profilometer, and the deviation of the surface shape relative to the ideal plane is calculated. This deviation is the actual radius deviation e at different cutting edges of the tool, while the ideal cutting edge radius of the tool is r. Since the one-to-one correspondence between x and θ at each sampling point is known, the relationship curve e(θ) between θ and e can be obtained from the xe relationship curve e(x) measured by the profilometer. Therefore, the actual radius R(θ) at different cutting edges of the tool can be expressed as:

[0087] R(θ)=e(θ)+r

[0088] Step 4: Based on the equations and parameters of the two processed parabolic surfaces, search for the coordinates (x, z) of ten sampling points near each sampling point using a KD-tree, then fit the plane and calculate the normal vector (V) at that sampling point.x V z Similarly to step three, for the apertures of the two parabolic surfaces in the dual-reflection optical system to be processed, the angles are evenly distributed within 20-25° and 40-60° respectively, to obtain the rotation axis angle y corresponding to each sampling point off the axis.

[0089] Substituting the angle y into R(θ), we obtain the actual radius of the cutting edge of the tool corresponding to each sampling point. Then, the path planning process in step three of this embodiment generates the target machining path, where the target machining path represents a series of machining path coordinates (X, Z, B).

[0090] A series of machining path coordinates are generated into a machine tool file, which is then imported into a cutting machine tool to machine the two surfaces respectively, thus completing the overall machining of the two-mirror optical system.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for co-fabrication of multi-surface devices, characterized in that, Specifically, the following steps are included: The rotation angle range of the shaft is obtained based on the multi-surface device to be processed; The range of rotation angles of the shaft can be obtained based on the multi-surface device to be processed, including: The position and orientation of the diamond tool are obtained by fixing the tool post on the machine tool spindle; The angle range of the shaft rotation is obtained by positioning and aligning the diamond tool with the processing surface of the multi-surface device to be processed in the cutting edge area. The tool position is obtained using the angular range of the rotation of the shaft. Obtaining the tool position using the angular range of the rotation of the shaft includes: Based on the angle range of the rotation of the shaft, the rotation of the shaft is controlled, and the machine tool position is obtained by using a tool setting device to make the diamond tool contact the tool setting block; The tool position is obtained using an optimization function based on the machine tool position; The optimization function is: ； in, This represents the component of the distance along the Z-axis between the center of the diamond tool's arc and the center of the rotation axis. Let X be the component of the distance between the center of the arc of the diamond tool and the center of the rotation axis along the X-axis. In order to make Minimum and The value of , This is the rotation angle value of the shaft. , The position of the machine tool when the arc-shaped contour of the diamond tool tip touches the tool setting block when the axis of rotation is 0°. For the shaft to rotate to When the arc-shaped contour of the tip of the diamond tool touches the tool block, the position of the machine tool is reached; A linkage machining path is obtained by path planning based on the parameters of the multi-surface device, the cutting radius of the diamond tool, and the tool position. The actual radius of the tool cutting edge is obtained using the aforementioned linkage machining path; Obtaining the actual radius of the tool cutting edge using the aforementioned linkage machining path includes: The cutting surface shape is obtained using a contour measuring device based on the aforementioned linkage machining path; The actual radius deviation is calculated using the cutting surface shape. The actual radius of the tool at different cutting edges is obtained based on the actual radius deviation and the ideal cutting edge radius of the tool. The angle of the rotating shaft at the sampling point on the axial surface is obtained by utilizing the angular range of the rotating shaft. Substitute the rotation angle corresponding to the off-axis sampling point into the actual radius curve of the tool at different cutting edges to obtain the actual radius of the tool cutting edge; A target machining path is generated based on the actual radius of the cutting edge, the parameters of the multi-surface device, and the position of the cutting tool; The multi-surface device to be processed is processed using the target processing path to achieve the co-processing of the multi-surface device.

2. The method for co-processing multi-surface devices according to claim 1, characterized in that, Based on the parameters of the multi-surface device, the cutting radius of the diamond tool, and the tool position, a path planning method is used to obtain the linkage machining path, including: The sampling points for the multi-surface device parameters are obtained based on the multi-surface device parameters. The coordinates of the sampling points corresponding to the multi-surface device parameter sampling points are obtained based on the KD tree using the sampling points of the multi-surface device parameter sampling points; The normal vector at the sampling point is calculated by using the coordinates of the sampling points corresponding to the sampling points of the multi-surface device parameters through plane fitting. Calculate the center coordinates of the cutting edge of the diamond tool based on the normal vector at the sampling point and the cutting edge radius of the diamond tool. The rotation angles corresponding to the sampling points of the multi-surface device parameters are obtained by uniformly distributing the rotation angle range of the shaft. The target motion is calculated by combining the center coordinates of the cutting edge with the rotation axis angles corresponding to the sampling points of the multi-surface device parameters and the cutting edge position. The linkage processing path is obtained based on the target motion amount.

3. The method for co-processing multi-surface devices according to claim 2, characterized in that, The coordinates of the tool cutting edge center are calculated as follows: ； ； in, The coordinates of the cutting edge center are: For sampling points, The cutting edge radius of the diamond tool. The normal vector at the sampling point. The rotation angle at each sampling point.

4. The method for co-processing multi-surface devices according to claim 3, characterized in that, The rotation angle at each sampling point is: ； in, The rotation angle at each sampling point, This refers to the range of angles the shaft can rotate during the machining process. , These represent the minimum and maximum position coordinates of the X-axis guide rail during the machining process.

5. The method for co-processing multi-surface devices according to claim 4, characterized in that, The target amount of exercise is: ； ； in, This represents the motion amount along the X-axis. This represents the motion amount corresponding to the Z-axis. This represents the component of the distance along the Z-axis between the center of the diamond tool's arc and the center of the rotation axis. Let X be the component of the distance between the center of the arc of the diamond tool and the center of the rotation axis along the X-axis. The rotation angle at each sampling point.

6. The method for co-processing multi-surface devices according to claim 1, characterized in that, The actual radius of the cutting edge at different points is: ； in, This represents the actual radius at different cutting edges of the tool. Rotation axis angle Actual radius deviation at different cutting edges of the cutting tool Relationship curve, The ideal cutting edge radius of the tool.

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