X-axis vibration collaborative fly-cutting system and method for large-range microstructure array

Abstract

The invention discloses an X-axis vibration collaborative fly-cutting system and method for a large-range microstructure array. The system comprises a fly-cutting disc, a workpiece, a manual heightening table, a heightening table, a machine tool shaft B, a machine tool shaft Z, a fly-cutting disc base, a machine tool shaft C and a machine tool shaft X; the machine tool B shaft is located on the machine tool Z shaft, the heightening table is fixed to the upper surface of the machine tool B shaft, the manual heightening table is fixed to the heightening table, the machine tool C shaft is located on the machine tool X shaft, the fly-cutting disc base is fixed to the machine tool C shaft, the fly-cutting disc is fixed to the fly-cutting disc base, the manual heightening table is used for installing a workpiece, and the fly-cutting disc 1 comprises a fly-cutting disc body and a turning tool. According to the designed tool path, a microstructure can be machined by rotating the main shaft by one circle, and the machining efficiency is high. According to the micro-structure fly-cutting method, the machining efficiency, machining precision and machining consistency of the micro-structure array are improved, only three-axis movement is needed, the structure is simple, and cost is low.

Description

Technical Field

[0001] The present invention belongs to the field of ultra-precision cutting, and relates to a fly-cutting system and method for a microstructure array with high machining consistency, in particular to an X-axis vibration collaborative fly-cutting system and method for a large-range microstructure array. Background Art

[0002] In the modern optical field, the importance of microstructure arrays is increasing day by day. Currently, they are key components of various advanced optical devices, such as collimators, wavefront sensors, microscopes, and fiber optic communication systems. Compared with non-traditional manufacturing methods based on high-energy particle beams and chemical etching, mechanical cutting can process more types of materials and is suitable for more complex surface shapes. Therefore, mechanical cutting, especially diamond mechanical cutting, has great prospects in the manufacture of microstructure arrays.

[0003] Currently, fast-slow tool servo diamond cutting is the mainstream mechanical processing method for microstructure arrays. During the processing, the tool moves up and down along the Z-axis according to the angular position of the workpiece to form the surface shape. Since the sharp edges between microstructures will cause uneven tool movement, vibrations will be induced, significantly reducing the shape accuracy and surface smoothness. To solve this problem, some researchers have proposed to extend the tool path. When cutting adjacent lenses, an additional smooth tool path is added, but this will increase the processing time and is only applicable to specific arrangements. In addition, some people have proposed to use an additional motion axis to decompose the cutting motion, decomposing the uneven tool movement into two smooth trajectories, but this will significantly increase the system cost, and its limited system dynamics may also reduce the efficiency and magnify the errors in the processing of large-area microstructure arrays. Even if the vibration problem is solved through path optimization and the introduction of multiple axes, due to the different cutting speeds at different microstructures during turning, it is difficult to ensure the machining consistency of microstructures.

[0004] Ultra-precision diamond milling is another main mechanical processing method for microstructure arrays. During the processing, the milling cutter rotates at a high speed to remove materials, and the feed per revolution is low, being good at processing brittle materials. In array processing, each microstructure is processed in turn, and the processing trajectory of each microstructure is the same, so it has high machining consistency. However, the processing efficiency of ultra-precision diamond milling is low, and the runout and vibration errors of the milling cutter are introduced, affecting the processing accuracy. Summary of the Invention

[0005] The purpose of the present invention is to provide an X-axis vibration collaborative fly-cutting system and method for a large-range microstructure array with high consistency, high precision, and high efficiency.

[0006] The technical solution adopted by the present invention is: an X-axis vibration collaborative fly-cutting system for a large-scale micro-structure array, including a fly-cutting disc, a workpiece, a manual adjustment platform, a heightening platform, a machine tool B-axis, a machine tool Z-axis, a fly-cutting disc base, a machine tool C-axis, and a machine tool X-axis;

[0007] The machine tool B-axis is located on the machine tool Z-axis, the heightening platform is fixed on the upper surface of the machine tool B-axis, the manual adjustment platform is fixed on the heightening platform, the machine tool C-axis is located on the machine tool X-axis, the fly-cutting disc base is fixed on the machine tool C-axis, the fly-cutting disc is fixed on the fly-cutting disc base, the manual adjustment platform is used for installing the workpiece, the fly-cutting disc 1 includes a fly-cutting disc body and a turning tool, and the turning tool is located at the front end of the fly-cutting disc body 10.

[0008] Further, the manual adjustment platform includes a fastening bolt, a fastening nut, a fine adjustment bolt, a fine adjustment fastening nut, an adjustment platform base, a coarse adjustment fastening nut, a coarse adjustment bolt, and an adjustment platform body. The adjustment platform body is connected to the upper part of the adjustment platform base, and the adjustment platform body and the adjustment platform base are connected by a fastening bolt, a fastening nut, a fine adjustment bolt, a fine adjustment fastening nut, a coarse adjustment fastening nut, and a coarse adjustment bolt.

[0009] Further, the turning tool is a natural diamond turning tool.

[0010] A fly-cutting method for the X-axis vibration collaborative fly-cutting system for a large-scale micro-structure array according to the above includes the following steps:

[0011] Step 1: Generate the tool path for cutting the k-th lens in a certain row according to the parameters of the micro-structure array and the tool. Let O F be the axis center of the machine tool C-axis 8, O W be the center of the sphere of the lens to be processed, O t be the tip of the turning tool, A t be the position where the turning tool initially contacts the workpiece, θ be the angle between the rake face of the turning tool and the vertical line, set the position when the turning tool is perpendicular to the vertical line as the zero point of the machine tool C-axis, θ is equal to the rotation angle of the machine tool C-axis, be the angle between the connection line of any position on the lens and O W and the vertical line. First, calculate

[0012]

[0013] r l is the curvature radius of the lens and also the nose radius of the turning tool, R s is the designed fly-cutting radius of gyration, θ0 is the angle between O F A t and the vertical line;

[0014] Then, establish the motion trajectory of the X-axis of the machine tool according to the motion trajectory of the C-axis of the machine tool:

[0015]

[0016] is the motion path of the X-axis of the machine tool during the cutting process of the k-th lens, d x is the distance between adjacent lenses;

[0017] Step 2, establish the transitional motion trajectory between the cutting processes of two lenses:

[0018]

[0019] is the transitional motion of the X-axis of the machine tool between the cutting of the k-th lens and the (k + 1)-th lens, f (k+1) (θ) is the motion trajectory of the k-th lens and the motion trajectory of the (k + 1)-th lens is the cubic spline interpolation curve between them, f (k +1) (θ) satisfies:

[0020]

[0021] t is the cutting time, n s is the rotational speed of the C-axis of the machine tool, a max is the maximum acceleration allowed for the operation of the machine tool;

[0022] Step 3, process the value of the turning radius for correcting fly cutting of a PxP lens array, 3 ≤ P ≤ 10. First, actually measure a certain lens in the processed PxP lens array to obtain the two-dimensional contour shape of the center of a certain lens along the tool tip movement direction, and then establish a lens surface simulation algorithm:

[0023]

[0024] T R (θ) is the rotation matrix around the axis of the C-axis of the machine tool, T X is the translation matrix of the X-axis of the machine tool, P T is the position matrix of the cutting edge in the tool coordinate system, z s is the height of the tool tip from the bottom end of the lens, h s is the maximum depth of the lens, S o is the plane matrix with a height equal to h s ;

[0025] According to the surface simulation algorithm, the theoretical two-dimensional contour shape is simulated. Then, the value of the turning radius of the fly-cutting is iterated in the simulation algorithm until the PV error between the theoretical two-dimensional contour shape and the actually measured two-dimensional contour shape is less than the threshold value. The turning radius of the fly-cutting obtained from the first iteration is denoted as

[0026] Step 4: Repeat Steps 1 to 3 to gradually reduce the topography error of the machining until the turning radius of the fly-cutting obtained from the nth iteration is obtained. The topography error of the machined PxP lens array meets the accuracy requirements.

[0027] Step 5: Substitute the turning radius of the fly-cutting obtained from the nth iteration into Steps 1 and 2 to generate the machining and transition motion trajectories of a single lens. The trajectory shapes of the machining and transition motions of all the lenses in the lens array are the same. Superimpose the machining and transition motion trajectories of a single lens to generate the machining trajectory of the QxQ lens array, where Q>10.

[0028] Furthermore, P is 5 and Q is 100.

[0029] The beneficial effects of the present invention are as follows: The tool trajectories of each lens machined by the present invention are the same, and the machined lenses have a high degree of consistency; in the present invention, the X-axis of the machine tool adopts a motion path similar to simple harmonic oscillation, which improves the stable operation speed of the C-axis and X-axis of the machine tool, and one lens can be machined in one rotation of the C-axis, avoiding surface tool marks and having high machining efficiency; in the present invention, the X-axis of the machine tool adopts a motion path similar to simple harmonic oscillation, which reduces the maximum acceleration during the motion, makes the machine tool more stable and has high machining accuracy; only two axes need to perform high-precision coordinated motion, and the other axis only needs to perform positioning motion, which has low requirements for the performance of the machine tool, thus greatly reducing the cost.

[0030] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of the X-axis vibration collaborative fly-cutting system of the present invention for a large-range micro-structure array;

[0032] Figure 2 is a schematic diagram of the fly-cutting disc of the X-axis vibration collaborative fly-cutting system of the present invention for a large-range micro-structure array;

[0033] Figure 3 is a schematic diagram of the manual adjustment platform of the X-axis vibration collaborative fly-cutting system of the present invention for a large-range micro-structure array;

[0034] Figure 4It is a tool path calculation flow chart of the X-axis oscillation collaborative fly-cutting method for a micro-structure array of the present invention;

[0035] Figure 5 It is a schematic diagram of the machining process of a single lens for the X-axis oscillation collaborative fly-cutting method of a micro-structure array of the present invention. Specific embodiments

[0036] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] The schematic diagram of the fly-cutting system of the present invention is shown in Figure 1 , which includes a fly-cutting disc 1, a workpiece 2, a manual height-adjusting platform 3, a height-increasing platform 4, a machine tool B-axis 5, a machine tool Z-axis 6, a fly-cutting disc base 7, a machine tool C-axis 8, and a machine tool X-axis 9. The machine tool B-axis 5 is located above the machine tool Z-axis 6. The height-increasing platform 4 is fixed on the upper surface of the machine tool B-axis 5. The manual height-adjusting platform 3 is fixed on the height-increasing platform 4. The machine tool C-axis 8 is located on the machine tool X-axis 9. The fly-cutting disc base 7 is fixed on the machine tool C-axis 8. The fly-cutting disc 1 is fixed on the fly-cutting disc base 7. The workpiece 2 is installed on the upper surface of the manual height-adjusting platform 3. The partial schematic diagram of the fly-cutting disc 1 of the present invention is shown in Figure 2 , which includes a fly-cutting disc main body 10 and a natural diamond turning tool 11. The natural diamond turning tool 11 is located at the front end of the fly-cutting disc main body 10. The partial schematic diagram of the manual height-adjusting platform 3 of the present invention is shown in Figure 3 , which includes a fastening bolt 12, a fastening nut 13, a fine-adjusting bolt 14, a fine-adjusting fastening nut 15, a height-adjusting platform base 16, a coarse-adjusting fastening nut 17, a coarse-adjusting bolt 18, and a height-adjusting platform main body 19. The height-adjusting platform main body 19 is connected to the upper part of the height-adjusting platform base 16. The height-adjusting platform main body 19 and the height-adjusting platform base 16 are connected by the fastening bolt 12, the fastening nut 13, the fine-adjusting bolt 14, the fine-adjusting fastening nut 15, the coarse-adjusting fastening nut 17, and the coarse-adjusting bolt 18. Before cutting, rotate the machine tool B-axis 5 to a suitable position and then lock it. The machine tool B-axis 5 is fixed and cannot move during the fly-cutting process. The workpiece 2 is fixed on the upper surface of the height-adjusting platform main body 19 by paraffin. The height of the workpiece 2 is initially adjusted by the coarse-adjusting bolt 18, and then the upper surface of the workpiece 2 is adjusted to be horizontal by adjusting the fine-adjusting bolts 14 at the four corners, and the height is finely adjusted according to the cutting depth. First, level the workpiece through the manual height-adjusting platform 3 and align the tool. Then, a micro-structure array is machined through the relative movement between the natural diamond arc tool 11 and the workpiece 2. According to the designed tool path, one micro-structure can be machined in one rotation of the main shaft, and the machining efficiency is high.

[0038] During the machining process of the present invention, the C-axis 8 of the machine tool rotates at a constant speed, and the X-axis 9 of the machine tool cooperates with the C-axis 8 of the machine tool to perform a similar simple harmonic oscillation motion to complete the fly-cutting machining of one row of lenses. After that, the Z-axis 6 of the machine tool moves the workpiece 2 so that the natural diamond turning tool 11 is located at the machining position of the next row of lenses, thereby gradually completing the fly-cutting machining of the entire lens array.

[0039] The machining process of the present invention is as Figure 4 shown. Taking a honeycomb spherical microlens array structure as an example, first determine the shape and position information of the microstructure array. The lens pitch is 50 μm, the radius of curvature is 220 μm, and the arrangement is 100×100. The radius of the natural diamond turning tool 11 used is 220 μm.

[0040] Step 1: Generate the tool path for cutting the k-th lens in a certain row according to the parameters of the microstructure array and the tool. As Figure 5 shown, O F is the axis center of the C-axis 8 of the machine tool, O W is the center of the sphere of the lens being machined, O t is the tip of the natural diamond turning tool 11, and A t is the position where the natural diamond turning tool 11 initially contacts the workpiece 2. θ is the angle between the rake face of the natural diamond turning tool 11 and the vertical line. The position when the natural diamond turning tool 11 is perpendicular to the vertical line is set as the zero point of the C-axis 8 of the machine tool, and θ is also equal to the rotation angle of the C-axis 8 of the machine tool. is the angle between the connection line of any position on the lens and O W and the vertical line. First, calculate

[0041]

[0042] r l is the radius of curvature of the lens and also the nose radius of the natural diamond turning tool 11, taking 0.220 mm. R s is the designed fly-cutting radius of gyration, with a designed value of 7.6 mm. θ0 is the angle between O F A t and the vertical line, taking 0.096.

[0043] Then, establish the motion trajectory of the X-axis 9 of the machine tool according to the C-axis 8 of the machine tool:

[0044]

[0045] is the motion path of the X-axis 9 of the machine tool during the cutting of the k-th lens, and d x is the pitch between adjacent lenses, taking 50 μm.

[0046] Step 2: Establish the transitional motion trajectory between the cutting processes of two lenses.

[0047]

[0048] is the transitional motion of the X-axis 9 of the machine tool during the cutting of the k-th lens and the (k + 1)-th lens, f (k+1) (θ) is the motion trajectory of the k-th lens and the motion trajectory of the (k + 1)-th lens is the cubic spline interpolation curve between them, f (k +1) (θ) satisfies:

[0049]

[0050] t is the cutting time, n s is the rotational speed of the C-axis 8 of the machine tool, a max is the maximum acceleration allowed for the operation of the machine tool, taking 65 mm / s 2 .

[0051] Step 3: Machine a 5x5 lens array to correct the value of the fly-cutting radius of gyration. First, actually measure a certain lens in the machined 5x5 lens array to obtain the two-dimensional contour shape of the center of a certain lens along the tool tip motion direction. Then establish a lens surface simulation algorithm:

[0052]

[0053] T R (θ) is the rotation matrix around the axis of the C-axis 8 of the machine tool, T X is the translation matrix of the X-axis 9 of the machine tool, P T is the position matrix of the cutting edge in the tool coordinate system, z s is the height of the tool tip from the bottom end of the lens, h s is the maximum depth of the lens, S o is the plane matrix with a height equal to h s .

[0054] According to the surface simulation algorithm, simulate to obtain the theoretical two-dimensional contour shape. Then, iterate the value of the fly-cutting radius of gyration in the simulation algorithm until the PV error between the theoretical two-dimensional contour shape and the actually measured two-dimensional contour shape is less than 10 nm. At this time, the fly-cutting radius of gyration obtained from the first iteration is denoted as

[0055] Step 4: Repeat Steps 1 to 3 to gradually reduce the machining topography error until the fly-cutting radius of gyration obtained from the n-th iteration The topography error of the machined 5x5 lens array meets the accuracy requirements.

[0056] Step Five, bring the turning radius of fly cutting in the nth iteration into the machining and transitional motion trajectories of a single lens generated in Step One and Step Two. The trajectory shapes of the machining and transitional motions of all lenses in the lens array are the same. Superimpose the machining and transitional motion trajectories of a single lens to generate the machining trajectory of a 100×100 lens array.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An X-axis vibration collaborative fly-cutting system for a large-scale microstructure array, characterized in that It includes a fly cutting disc (1), a workpiece (2), a manual height adjusting platform (3), a height increasing platform (4), a machine tool B axis (5), a machine tool Z axis (6), a fly cutting disc base (7), a machine tool C axis (8), and a machine tool X axis (9); The machine tool B axis (5) is located on the machine tool Z axis (6), the height increasing platform (4) is fixed on the upper surface of the machine tool B axis (5), the manual height adjusting platform (3) is fixed on the height increasing platform (4), the machine tool C axis (8) is located on the machine tool X axis (9), the fly cutting disc base (7) is fixed on the machine tool C axis (8), the fly cutting disc (1) is fixed on the fly cutting disc base (7), the manual height adjusting platform (3) is used for installing the workpiece (2), the fly cutting disc 1 includes a fly cutting disc main body (10) and a turning tool (11), and the turning tool (11) is located at the front end of the fly cutting disc main body 10.

2. The X-axis vibration collaborative fly-cutting system for a large-scale microstructure array according to claim 1, characterized in that, The manual height adjusting platform (3) includes a fastening bolt (12), a fastening nut (13), a fine adjustment bolt (14), a fine adjustment fastening nut (15), a height adjusting platform base (16), a coarse adjustment fastening nut (17), a coarse adjustment bolt (18), and a height adjusting platform main body (19). The height adjusting platform main body (19) is connected to the upper part of the height adjusting platform base (16), and the height adjusting platform main body (19) and the height adjusting platform base (16) are connected by the fastening bolt (12), the fastening nut (13), the fine adjustment bolt (14), the fine adjustment fastening nut (15), the coarse adjustment fastening nut (17), and the coarse adjustment bolt (18).

3. The X-axis vibration collaborative fly-cutting system for a large-range micro-structure array according to claim 1, characterized in that, The turning tool (11) is a natural diamond turning tool.

4. The fly-cutting method of the fly-cutting system with X-axis vibration cooperation for a large-range micro-structure array according to any one of claims 1-3, characterized in that, It includes the following steps: Step 1: Generate the tool path for cutting the k-th lens in a certain row according to the parameters of the microstructure array and the tool. Let O F be the axis center of the C-axis 8 of the machine tool, O W be the center of the sphere of the lens being machined, O t be the tip of the turning tool (11), A t be the initial contact position of the turning tool (11) and the workpiece (2). θ is the angle between the rake face of the turning tool (11) and the vertical line. Set the position when the turning tool (11) is perpendicular to the vertical line as the zero point of the C-axis (8) of the machine tool. θ is equal to the rotation angle of the C-axis (8) of the machine tool. be the angle between the line connecting any position on the lens and O W and the vertical line. First, calculate according to the rotation angle of the C-axis (8) of the machine tool r l is the radius of curvature of the lens and also the nose radius of the turning tool (11), R s is the designed turning radius of fly cutting, and θ0 is the angle between O F A t and the vertical line; Then, establish the motion trajectory of the machine tool X axis (9) according to the motion trajectory of the machine tool C axis (8): is the movement path of the X-axis (9) of the machine tool during the cutting process of the k-th lens, d x is the distance between adjacent lenses; Step two, establish the transitional motion trajectory between two lens cutting processes: is the transitional movement of the machine tool X-axis (9) between the cutting of the k-th lens and the (k + 1)-th lens, f (k+1) (θ) is the movement trajectory of the k-th lens and the movement trajectory of the (k + 1)-th lens is the cubic spline interpolation curve between them, f (k+1) (θ) satisfies: t is the cutting time, n s is the rotational speed of the C-axis (8) of the machine tool, a max is the maximum acceleration allowed for the operation of the machine tool; Step three, process a group of PxP lens arrays to correct the value of the turning radius of fly cutting, 3 ≤ P ≤ 10. First, actually measure a certain lens in the processed PxP lens array to obtain the two-dimensional contour shape of the center of a certain lens along the tool tip movement direction, and then establish a lens surface simulation algorithm: T R (θ) is the rotation matrix about the axis of the C-axis (8) of the machine tool, T X is the translation matrix of the X-axis (9) of the machine tool, P T is the position matrix of the cutting edge in the tool coordinate system, z s is the height of the bottom end of the tool distance lens, h s is the maximum depth of the lens, S o is the plane matrix with a height equal to h s ; The theoretical two-dimensional contour shape is obtained by simulating according to the surface simulation algorithm. Then, the value of the turning radius of fly cutting is iterated in the simulation algorithm until the PV error between the theoretical two-dimensional contour shape and the actually measured two-dimensional contour shape is less than the threshold value, and the turning radius of fly cutting for the first iteration is recorded as Step 4: Repeat Steps 1 to 3 to gradually reduce the machining profile error until the turning radius of fly cutting for the nth iteration is obtained. The profile error of the machined PxP lens array meets the accuracy requirements. Step 5: Substitute the turning radius of fly cutting in the nth iteration into the machining and transitional motion trajectories of a single lens generated in Step 1 and Step 2. The trajectory shapes of the machining and transitional motions of all lenses in the lens array are the same. Superimpose the machining and transitional motion trajectories of a single lens to generate the machining trajectory of a QxQ lens array, where Q >

10.

5. The fly-cutting method of the X-axis vibration collaborative fly-cutting system for a large-scale micro-structure array according to claim 4, characterized in that, P is 5 and Q is 100.

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