Common processing method of multi-surface device

Abstract

The invention discloses a common-body machining method for a multi-surface device, and relates to the technical field of ultra-precision machining. The common-body machining method comprises the steps that the rotating angle range of a rotating shaft is obtained according to a to-be-machined multi-surface device; the cutter position is obtained through the rotating angle range of the rotating shaft; path planning is conducted according to the multi-surface device parameters, the cutting edge radius of the diamond cutter and the cutter position, and a linkage machining path is obtained; the actual radius of the cutting edge of the tool is obtained through the linkage machining path; path planning is carried out according to the actual radius of the cutting edge of the tool, the multi-surface device parameters and the tool position to generate a target machining path; and processing the to-be-processed multi-surface device by utilizing the target processing path to realize common processing of the multi-surface device. The problem that the radiuses of different cutting edge areas of the cutter are different when the cutter rotates for cutting is solved, the error is compensated and corrected, and a common body machining method of different cutting edge areas of the diamond cutter is adopted during XZB axis linkage to achieve common body machining forming of a device with a plurality of surfaces.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-precision machining, and in particular relates to a common body machining method for multi-surface devices. Background Art

[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 reflectors surrounded by multiple surfaces. These multi-surface devices not only require each surface to have high surface accuracy, but also require the relative position and posture between different surfaces to have high precision assurance, otherwise it will affect the installation error, optical performance and other application effects of such devices.

[0003] Generally speaking, multi-surface devices are cut by split cutting, that is, the device is adjusted and re-clamped on the processing machine when processing each surface. At this time, the posture between different surfaces is only adjusted by tool setting process or positioning block, and the accuracy of this process is often difficult to guarantee. Co-body processing can realize the processing of multiple surfaces by rotating the device without moving the device, and the relative posture of different surfaces is guaranteed by the machine tool axis. However, the current co-body processing method only uses the axis to adjust the posture of the processing surface, and no longer rotates the axis when cutting the surface. At this time, it is limited by the limited cutting edge of the diamond tool, and the processable area and surface curvature are constrained. Especially when processing some compact multi-surface devices, it is impossible to generate a processing path without collision without rotating the tool.

[0004] Therefore, there is an urgent need for a common processing method for multi-surface devices to address the deficiencies in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a method for co-processing a multi-surface device, so as to realize the co-processing of the multi-surface device.

[0006] To achieve the above object, the present invention provides a method for processing a multi-surface device, comprising the following steps:

[0007] Obtaining the angular range of the rotation of the rotating shaft according to the multi-surface device to be processed;

[0008] Obtaining the tool position using the angular range of rotation of the rotating shaft;

[0009] Performing path planning according to multi-surface device parameters, diamond tool edge radius and tool position to obtain a linkage processing path;

[0010] Using the linkage machining path to obtain the actual radius of the tool edge;

[0011] Performing path planning according to the actual radius of the tool edge, the multi-surface device parameters and the tool position to generate a target processing path;

[0012] The target processing path is used to process the multi-surface device to be processed to achieve the common processing of the multi-surface device.

[0013] Optionally, obtaining the angle range of the rotating shaft according to the multi-surface device to be processed includes:

[0014] Obtain the position and posture of the diamond tool according to the fixed tool holder of the machine tool rotating axis;

[0015] The angle range of rotation of the rotating shaft is obtained according to the position and posture 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 by using the angle range of the rotating shaft includes:

[0017] Based on the angular range of the rotation of the rotating shaft, the rotation of the rotating shaft is controlled, and the position of the machine tool is obtained by using a tool setting instrument to contact the tool setting block with the diamond tool;

[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 distance between the center of the diamond tool arc and the center of the rotating shaft along the Z-axis direction, D is the distance between the center of the diamond tool arc and the center of the rotating shaft along the X-axis direction, arc min‖·‖ is the value of L and D when · is minimized, θ i is the axis angle value, i = 1, 2, 3, 4, 5, (X0, Z0) is the position of the machine tool when the arc-shaped contour at the top of the diamond tool touches the tool setting block when the axis is 0°, (X i ,Z i ) is the axis of rotation to θ i The position of the machine tool when the arc-shaped contour at the top of the diamond tool touches the tool setting block.

[0022] Optionally, performing path planning according to the multi-surface device parameters, the diamond tool edge radius and the tool position to obtain the linkage processing path includes:

[0023] Acquire a multi-surface device parameter sampling point according to the multi-surface device parameter;

[0024] Using the multi-surface device parameter sampling points, based on the KD tree, the sampling point coordinates corresponding to the multi-surface device parameter sampling points are obtained;

[0025] Calculate the normal vector at the sampling point by plane fitting using the sampling point coordinates corresponding to the sampling point of the multi-surface device parameter sampling point;

[0026] Calculating the center coordinates of the cutting edge of the diamond tool according to the normal vector at the sampling point and the cutting edge radius of the diamond tool;

[0027] Obtaining the rotation axis angles corresponding to the multi-surface device parameter sampling points by evenly distributing the rotation axis angles according to the rotation angle range of the rotation axis;

[0028] Calculate the target motion amount by using the tool edge center coordinates and the rotation axis angle corresponding to the multi-surface device parameter sampling point in combination with the tool position;

[0029] The linkage processing path is obtained according to the target motion amount.

[0030] Optionally, calculate the tool edge center coordinates as:

[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 ) is the center coordinate of the tool edge, (x n ,z n ) is the sampling point, R(θ n ) is the cutting edge radius of the diamond tool, (V x ,V z ) is the normal vector at the sampling point.

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

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

[0036] Among them, θ nis the axis angle at each sampling point, [α1, α2] is the angle range of the axis rotation during the machining process, and x n_min 、x n_max They are respectively the minimum and maximum position coordinates of the X-axis guide rail during the machining process.

[0037] Optionally, the target amount of exercise 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 is the corresponding movement of the X axis, Z n is the corresponding motion of the Z axis, L is the distance between the center of the diamond tool arc and the center of the rotating shaft along the Z axis, D is the distance between the center of the diamond tool arc and the center of the rotating shaft along the X axis, θ n is the rotation axis angle at each sampling point.

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

[0042] Acquiring the cutting surface shape by using a contour measuring device according to the linkage processing path;

[0043] calculating the actual radius deviation using the cutting surface shape;

[0044] Obtaining the actual radius at the cutting edge of the tool according to the actual radius deviation and the ideal cutting edge radius of the tool;

[0045] The rotation angle of the rotating shaft corresponding to the sampling point of the off-axis surface is obtained by using the rotation angle range of the rotating shaft;

[0046] The rotation axis angle corresponding to the off-axis surface sampling point is substituted into the actual radius curve at the tool edge to obtain the actual radius of the tool edge.

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

[0048] R(θ)=e(θ)+r

[0049] Among them, R(θ) is the actual radius of the tool at different cutting edges, 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 prior art, the present invention has the following beneficial effects:

[0051] The co-processing method of a multi-surface device of the present invention can avoid problems such as insufficient cutting edge of the tool or collision in the processing path when the tool does not rotate; when the tool rotates, if the position of the tool relative to the rotating shaft is not calibrated, a high-precision processing path cannot be generated. The present invention can achieve high-precision calibration without trial cutting by touching and optimizing the tool block; the present invention solves the problem that the radii of different cutting edge areas of the tool are different when the tool is rotating and cutting, and corrects the error by compensation; the present invention adopts a co-processing method of different cutting edge areas of a diamond tool when the XZB axis is linked, which can realize co-processing and forming of devices with multiple surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 A flowchart of a common processing method for a multi-surface device according to an embodiment of the present invention;

[0054] Figure 2 A schematic diagram of a second reflective system to be processed according to an embodiment of the present invention;

[0055] Figure 3 A structural diagram of a common processing machine tool proposed in an embodiment of the present invention;

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

[0057] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0058] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0059] Embodiment 1

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

[0061] S1. Collision test: First, install the multi-surface device to be processed on the spindle of the processing machine tool, fix the tool holder on the machine tool shaft 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 whole process. Record the angular range of the shaft rotation during the processing process [α1, α2].

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

[0063] The tool setting block is fixed on the spindle. The rotation of the shaft is controlled to multiple angles based on the angular range [α1, α2] within which the shaft can rotate when machining each surface. The tool setting block is contacted with a diamond tool by means of a tool setting instrument, and the positions of the movement of each axis of the machine tool are recorded. Based on these machine tool positions, D and L are calculated using an optimization function.

[0064] S3, linkage processing path generation: the linkage processing path is calculated according to the multi-surface device parameters, the diamond tool edge radius and other machine tool parameters and the tool position parameters D and L, wherein the multi-surface device parameters are the equations and parameters of each surface of the multi-surface device to be processed, which are provided by the processing party and are known information; specifically, the initial linkage processing path is calculated by the following method:

[0065] First, the B-axis angle is assigned, and multiple sampling points (x n ,z n ), then search for the coordinates of several sampling points near each sampling point through the KD tree; use the coordinates of several sampling points near each sampling point to perform plane fitting and calculate the normal vector (V x ,V z ); According to the normal vector at the sampling point (V x ,V z ) and the diamond tool edge radius R(θ n ) Calculate the tool edge center coordinates (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, according to the rotation angle range [α1, α2] of the rotating shaft determined in S1 of the first embodiment, the diameter range [x n_min ,x n_max ], the rotation axis 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, according to the tool edge center coordinates (X c ,Z c ) and the rotation axis angle θ at each sampling point n , and combine L and D to calculate the target motion, that is, the corresponding motion X of 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] Among them, x n_min 、x n_max They are respectively the minimum and maximum position coordinates of the X-axis guide rail during the machining process.

[0074] At this point, the linkage machining path can be expressed as a series of machine tool coordinates (X n ,Z n ,θ n ), calculated.

[0075] S4, diamond tool edge radius compensation: according to the initial processing path in S3 of the first embodiment, a plane is processed, and the processed surface shape is measured by a contour measuring device or a surface shape measuring device. Since the rotation axis angles at different positions are different during the processing, the tool edge areas used are different, so the actual radius at different tool edges is calculated according to the measurement results, and the corresponding relationship between the rotation axis angle and the actual radius is obtained;

[0076] Based on the multi-surface device parameters, the coordinates of multiple sampling points near each sampling point are searched through the KD tree, and 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 angular range [α1, α2] in which the rotation axis of each surface in the multi-surface device to be processed can rotate, and the corresponding rotation axis angle at each sampling point on the off-axis surface is obtained.

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

[0078] Embodiment 2

[0079] like Figure 2 As shown, taking the donor cutting process of a two-reflection system with two off-axis paraboloids as an example, a common body processing method for a multi-surface device is provided, and the detailed implementation process is as follows:

[0080] Step 1: Figure 3 As shown, the blank of the two-reflection optical system to be processed is installed on the main spindle of the processing machine tool, the tool holder 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 multi-axis linkage cuts the two surfaces, the contact position between the diamond tool and the processing surface of the two-reflection optical system to be processed is in the cutting edge area, and no collision occurs throughout the whole process, and then the angle range of the rotating shaft when processing each surface is recorded, wherein the rotatable angles of the B-axis of the two surfaces are 20-25° and 40-60° respectively.

[0081] Step 2: Fix the tool setting block on the spindle, and control the rotation of the shaft to 5 angles according to the rotation angles of the B axis of the two surfaces. Observe in the field of view of the machine tool tool setting instrument, when the arc-shaped contour of the top of the diamond tool is tangent to the flat contour of the tool setting block, and record the position of the machine tool Z axis movement. The detailed implementation process is as follows:

[0082] like Figure 4 As shown in the figure, assuming that the B axis (i.e. the rotating axis) is at 0°, the machine tool position when touching the tool setting block is (X0, Z0), and the B axis (i.e. the rotating axis) rotates to θ i (i=1,2,3,4,5), the machine tool positions when touching the tool setting block are (Xi ,Z i ), then D and L are calculated according to these machine tool positions through the optimization function, and the optimization function is:

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

[0084] Where L is the distance between the center of the diamond tool arc and the center of the rotating shaft along the Z axis, D is the distance between the center of the diamond tool arc and the center of the rotating shaft along the X axis, arcmin||·|| is the value of L and D when · is minimized, θ i is the axis angle value, i = 1, 2, 3, 4, 5, (X0, Z0) is the position of the machine tool when the arc-shaped contour at the top of the diamond tool touches the tool setting block when the axis is 0°, (X i ,Z i ) is the axis of rotation to θ i The position of the machine tool when the arc-shaped contour at the top of the diamond tool touches the tool setting block.

[0085] Step 3, generate two XZB linked planar machining paths. In order to make the B-axis angle range cover the two parabolic angle ranges of step one, the angle ranges used by the two paths are 15-30° and 35-65° respectively; the radii of the two circular aperture planes processed are 10 mm and 20 mm respectively, and the sampling points are generated at intervals of 10 μm in the XOZ plane. Then, 15-30° is linearly and evenly distributed in the 10 mm aperture, and 35-65° is linearly and evenly distributed in the 20 mm aperture. The coordinates (x, z) at each sampling point and the corresponding rotation axis (ie, B-axis) angle θ can be calculated; finally, generate a linked machining path and cut according to the calculation method in S3 of Example 1.

[0086] The profiler is used to measure the surface shape after cutting and calculate the deviation of the surface shape relative to the ideal plane. This deviation is the actual radius deviation e at different cutting edges of the tool, and 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 based on the xe relationship curve e(x) measured by the profiler, so 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 paraboloids being processed, search for the coordinates (x, z) of ten sampling points near each sampling point through the KD tree, then fit the plane and calculate the normal vector (Vx ,V z ); Similar to step 3, for the apertures of the two paraboloids in the two-mirror 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 on the off-axis surface.

[0089] Substitute the angle y into R(θ), that is, obtain the actual radius of the tool edge corresponding to each sampling point, and then the path planning process in step 3 of the second embodiment of the present invention generates a target processing path, where the target processing path represents a series of processing path coordinates (X, Z, B);

[0090] A series of processing path coordinates are generated into machine tool files, which are imported into the cutting machine to process the two surfaces separately, thus completing the co-processing 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 rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does 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 processing a multi-surface device, characterized in that: The specific steps include: Obtaining the angular range of the rotation of the rotating shaft according to the multi-surface device to be processed; Obtaining the tool position using the angular range of rotation of the rotating shaft; Performing path planning according to multi-surface device parameters, diamond tool edge radius and tool position to obtain a linkage processing path; Using the linkage machining path to obtain the actual radius of the tool edge; Performing path planning according to the actual radius of the tool edge, the multi-surface device parameters and the tool position to generate a target processing path; The target processing path is used to process the multi-surface device to be processed to achieve the common processing of the multi-surface device.

2. The method for processing a multi-surface device according to claim 1, characterized in that: The angle range of the rotating shaft obtained according to the multi-surface device to be processed includes: Obtain the position and posture of the diamond tool according to the fixed tool holder of the machine tool rotating axis; The angle range of rotation of the rotating shaft is obtained according to the position and posture 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.

3. The method for processing a multi-surface device according to claim 2, characterized in that: Obtaining the tool position using the angle range of the rotating shaft includes: Based on the angular range of the rotation of the rotating shaft, the rotation of the rotating shaft is controlled, and the position of the machine tool is obtained by using a tool setting instrument to contact the tool setting block with the diamond tool; The tool position is obtained using an optimization function based on the machine tool position.

4. The method for processing a multi-surface device according to claim 3, characterized in that: The optimization function is: [L,D]=arc min||LL cos(θ i )+D sin(θ i )+(Z i -Z0)|| Where L is the distance between the center of the diamond tool arc and the center of the rotating shaft along the Z axis, D is the distance between the center of the diamond tool arc and the center of the rotating shaft along the X axis, arc min||·|| is the value of L and D when · is minimized, θ i is the axis angle value, i = 1, 2, 3, 4, 5, (X0, Z0) is the position of the machine tool when the arc-shaped contour at the top of the diamond tool touches the tool setting block when the axis is 0°, (X i ,Z i ) is the axis of rotation to θ i The position of the machine tool when the arc-shaped contour at the top of the diamond tool touches the tool setting block.

5. The method for processing a multi-surface device according to claim 1, characterized in that: The path planning based on the multi-surface device parameters, the diamond tool edge radius and the tool position to obtain the linkage processing path includes: Acquire a multi-surface device parameter sampling point according to the multi-surface device parameter; Using the multi-surface device parameter sampling points, based on the KD tree, the sampling point coordinates corresponding to the multi-surface device parameter sampling points are obtained; Calculate the normal vector at the sampling point by plane fitting using the sampling point coordinates corresponding to the sampling point of the multi-surface device parameter sampling point; Calculating the center coordinates of the cutting edge of the diamond tool according to the normal vector at the sampling point and the cutting edge radius of the diamond tool; Obtaining the rotation axis angles corresponding to the multi-surface device parameter sampling points by evenly distributing the rotation axis angles according to the rotation angle range of the rotation axis; Calculate the target motion amount by using the tool edge center coordinates and the rotation axis angle corresponding to the multi-surface device parameter sampling point in combination with the tool position; The linkage processing path is obtained according to the target motion amount.

6. The method for processing a multi-surface device according to claim 5, characterized in that: Calculate the center coordinates of the tool edge: X c =x n +R(θ n )*V x Z c =z n +R(θ n )*V z Among them, (X c ,Z c ) is the center coordinate of the tool edge, (x n ,z n ) is the sampling point, R(θ n ) is the cutting edge radius of the diamond tool, (V x ,V z ) is the normal vector at the sampling point.

7. The method for processing a multi-surface device according to claim 6, characterized in that: The rotation axis angle at each sampling point is: i n =α1+(x n -x n_min )(α1-α2) / (x n_min -x n_max ) Among them, θ n is the axis angle at each sampling point, [α1, α2] is the angle range of the axis rotation during the machining process, and x n_min 、x n_max They are respectively the minimum and maximum position coordinates of the X-axis guide rail during the machining process.

8. The method for processing a multi-surface device according to claim 7, characterized in that: The target amount of exercise is: X n =X c +L sin(θ n )-D cos(θ n ) Z n =Z c +L cos(θ n )+D sin(θ n ) Among them, X n is the corresponding movement of the X axis, Z n is the corresponding motion of the Z axis, L is the distance between the center of the diamond tool arc and the center of the rotating shaft along the Z axis, D is the distance between the center of the diamond tool arc and the center of the rotating shaft along the X axis, θ n is the rotation axis angle at each sampling point.

9. The method for processing a multi-surface device according to claim 1, characterized in that: Using the linkage machining path to obtain the actual radius of the tool edge includes: Acquiring the cutting surface shape by using a contour measuring device according to the linkage processing path; calculating the actual radius deviation using the cutting surface shape; Obtaining the actual radius at the cutting edge of the tool according to the actual radius deviation and the ideal cutting edge radius of the tool; The rotation angle corresponding to the off-axis surface sampling point is obtained by using the rotation angle range of the rotation axis; The rotation axis angle corresponding to the off-axis surface sampling point is substituted into the actual radius curve at the tool edge to obtain the actual radius of the tool edge.

10. The method for processing a multi-surface device according to claim 9, characterized in that: The actual radius of the tool at different cutting edges is: R(θ)=e(θ)+r Among them, R(θ) is the actual radius of the tool at different cutting edges, 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.

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