Machining method of large-size high-precision optical part

Abstract

The invention relates to the technical field of optical part machining, and provides a large-size high-precision optical part machining method which comprises the steps that a first side face, a second side face, a third side face and a fourth side face are machined to a first surface shape parameter; the disc is placed on the platform, the microcrystalline block is arranged between the platform and the disc in a cushion mode, the second end face of the optical part is downwards placed into the avoiding hole, then the positioning plate is installed on the disc, and the positioning plate abuts against the first side face, the second side face, the third side face and the fourth side face; grinding and polishing the first end surface to a first surface shape parameter, and ensuring that the first end surface is perpendicular to the four side surfaces and the angle error is not greater than a first angle threshold value; and according to the method for machining the first end face, the second end face is frosted and polished to the first surface shape parameter. According to the machining method, through the reasonable technological process and the design of the special end face machining tool, a traditional optical cold machining method can be used for machining large-size and high-precision optical parts.

Description

Technical Field

[0001] The invention relates to the technical field of optical parts processing, and more specifically, to a processing method for large-size and high-precision optical parts. Background Art

[0002] Optical parts processing refers to the process of precision machining various optical materials to meet specific optical performance requirements. These parts are widely used in optical instruments, laser equipment, imaging systems, optical communications and other fields. According to different needs, optical parts processing can be divided into multiple steps, including but not limited to design, material selection, rough machining, fine machining, polishing, coating, etc.

[0003] For the processing of optical parts with a cubic appearance, six faces need to be polished. Conventional processing methods can process large side faces, but when the size of the optical parts is large, conventional processing methods cannot meet the requirements for processing the two end faces. On the one hand, due to the influence of the large size, the two end faces of the parts are not easy to be stably positioned, resulting in poor processing results. On the other hand, due to the unstable positioning, the safety and rationality of the processing are reduced. As a result, conventional processing methods cannot meet the processing needs of large-size optical parts, and specific processing tools and detection methods are required.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the invention

[0005] The purpose of the present invention is to provide a method for processing large-size and high-precision optical parts, so as to solve the technical problem that conventional processing methods cannot meet the processing requirements of large-size optical parts.

[0006] To achieve the above-mentioned purpose, the present invention provides a method for processing a large-size high-precision optical part, wherein the optical part is in the shape of a cube, and comprises a first side surface, a second side surface, a third side surface, a fourth side surface connected in sequence, and a first end surface and a second end surface arranged oppositely; and further provides a positioning tool, wherein the positioning tool comprises a disc, a positioning plate and a microcrystalline block, wherein a avoidance hole is arranged at the center of the disc, the positioning plate is detachably connected to the top of the disc, and the microcrystalline block is protrudingly arranged at the bottom of the disc;

[0007] The processing method comprises:

[0008] Processing the first side surface, the second side surface, the third side surface and the fourth side surface to first surface shape parameters;

[0009] Apply protective glue to the four sides of the optical component for protection, place the disc on the platform, place the microcrystalline block between the platform and the disc, put the second end face of the optical component into the avoidance hole with the second end face facing downward, and then install the positioning plate to the disc, the positioning plate stops at the first side face, the second side face, the third side face and the fourth side face, and fill the gap between the optical component and the positioning plate with yellow wax;

[0010] Frosting and polishing the first end surface to a first surface shape parameter to ensure that the first end surface is perpendicular to the four side surfaces and the angle error is not greater than a first angle threshold;

[0011] Place the first end face downward into the avoidance hole, and reinforce the four side surfaces by the positioning plate;

[0012] According to the method for processing the first end face, grinding and polishing the second end face to the first surface shape parameter, ensuring that the second end face is parallel to the first end face and the parallel error is not greater than a first parallel threshold;

[0013] Remove the plate and clean the optical parts.

[0014] Furthermore, the grinding and polishing of the first end surface to the first surface shape parameters specifically include:

[0015] The positioning plate and the first end surface are sanded by hand, the first dimension is removed by using coarse sand, and the second dimension is removed by using fine sand. While removing the dimension of the first end surface, the inclination angle of the first end surface is continuously adjusted to ensure that the first end surface is perpendicular to the four side surfaces and the angle error is not greater than the first angle threshold;

[0016] Polish the positioning plate and the first end face as a whole, use a ring polishing device to perform high-speed polishing to remove the third dimension, use a comparator to detect the angles between the four side faces and the first end face, and based on the detection values, polish the first end face at a low speed to the first surface parameter, and make the first end face perpendicular to the four side faces and the angle error is no greater than the first angle threshold.

[0017] Further, the step of polishing the first end surface to a first surface shape parameter at a low speed according to the detection value specifically includes:

[0018] When the test value shows a sharp angle, increase the polishing pressure on the side of the sharp angle to remove more size on the side of the sharp angle;

[0019] When the test value shows a blunt angle, increase the polishing pressure on the side opposite to the sharp angle.

[0020] Furthermore, the method of processing the first end face, grinding and polishing the second end face to the first surface shape parameter specifically includes:

[0021] Sand the positioning plate and the second end surface as a whole by hand, use coarse sand to remove the first dimension, and then use fine sand to remove the second dimension. While removing the dimension of the second end surface, adjust the inclination angle of the second end surface to ensure that the second end surface is perpendicular to the four side surfaces and the angle error is not greater than the first angle threshold;

[0022] The positioning plate and the second end face are polished as a whole, and the third dimension is removed by high-speed polishing using a ring polishing device. A comparator is used to detect the angles between the four side faces and the second end face. According to the detection values, the second end face is polished at a low speed to the first surface parameters, and the second end face is made perpendicular to the four side faces and the angle error is not greater than the first angle threshold.

[0023] Furthermore, after the four sides are reinforced by the positioning plate, the method further comprises:

[0024] The gap between the optical component and the positioning plate is filled with yellow wax.

[0025] Furthermore, after polishing the first end surface and the second end surface, the method further comprises:

[0026] The first end surface and the second end surface are chamfered.

[0027] In some embodiments, processing the second side surface specifically includes:

[0028] Process the second side surface to the first surface shape parameters, control the edge thickness difference to be no greater than the first thickness threshold, control the angle between the second side surface and the first side surface to be 90°, and the angle error to be no greater than the first angle threshold.

[0029] Furthermore, the processing of the third side surface specifically includes:

[0030] Taking the first side surface as a reference plane, the third side surface is processed to the first surface shape parameter, the edge thickness difference is controlled to be no greater than a first thickness threshold, the third side surface is controlled to be parallel to the first side surface, and the parallel error is controlled to be no greater than a first parallel threshold.

[0031] In some embodiments, processing the fourth side surface specifically includes:

[0032] Taking the second side surface as the reference plane, the fourth side surface is processed to the first surface shape parameter, the edge thickness difference is controlled to be no greater than the first thickness threshold, the fourth side surface is controlled to be parallel to the second side surface, and the parallel error is controlled to be no greater than the first parallel threshold.

[0033] Furthermore, after processing the first side surface, the second side surface, the third side surface and the fourth side surface, it also includes: chamfering the first side surface, the second side surface, the third side surface and the fourth side surface.

[0034] The processing method and positioning tooling of large-size and high-precision optical parts provided by the present invention have at least the following beneficial effects:

[0035] This processing method first processes the four side faces of the optical part. When processing the first end face and the second end face, a special positioning tool is used to stably position the optical part. The positioning tool can stably support the four side faces of the optical part so that the large-sized optical part can be stably maintained in a vertical state. The first end face and the second end face are then processed. Since the optical part can be stably supported by the positioning tool, the stability of the first end face and the second end face during processing is improved, and high-precision processing of the first end face and the second end face is achieved. Therefore, through a reasonable process flow and the design of special end face processing tooling, large-sized and high-precision optical parts can be processed using traditional optical cold processing methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A flowchart of a method for processing large-size and high-precision optical parts provided by an embodiment of the present invention;

[0038] Figure 2 A schematic diagram of the structure of an optical component provided by an embodiment of the present invention;

[0039] Figure 3 A schematic diagram of the structure of a positioning tool provided in an embodiment of the present invention;

[0040] Figure 4 A schematic diagram of the structure of a positioning plate provided in an embodiment of the present invention;

[0041] Figure 5 A schematic diagram of the structure of a disc provided in an embodiment of the present invention;

[0042] Figure 6 A schematic diagram of the structure of an optical component provided by an embodiment of the present invention when positioned in a positioning tool.

[0043] Among them, the reference numerals in the figure are:

[0044] 1. Optical parts;

[0045] 11. first side surface; 12. second side surface; 13. third side surface; 14. fourth side surface; 15. first end surface; 16. second end surface;

[0046] 2. Positioning tooling;

[0047] 21. Disc; 211. Avoidance hole;

[0048] 22, positioning plate; 221, first plate body; 222, second plate body; 223, top surface; 224, bottom surface; 225, observation hole;

[0049] 23. Microcrystalline block. DETAILED DESCRIPTION

[0050] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0051] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly or indirectly located on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on the present technical solution. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0052] To achieve the above objectives, the first aspect of the present invention provides a method for processing large-sized and high-precision optical parts. The following describes the method for processing large-sized and high-precision optical parts according to an embodiment of the present invention in conjunction with the accompanying drawings.

[0053] First, some terms appearing in this embodiment are explained:

[0054] Surface shape: PV (Peak to valley), also called peak to valley value, is a common indicator of optical surface shape quality. It refers to the height difference between the highest point and the lowest point within the sampling range (based on 2D contours or 3D data maps) after removing the reference plane. The PV value is in physical length units, and its meaning is easy to understand. Based on the required reference plane, the maximum deviation range of all pixels directly reflects the processing quality of the current optical surface. Based on the experience of long-term optical testing in the past, the PV value and another important surface shape indicator RMS often maintain a certain proportional relationship, generally around 2:1.

[0055] Surface defects (finish): pitting, scratches, broken edges, and bubbles on the surface of optical products.

[0056] Edge thickness difference: the difference in thickness of the part edges.

[0057] See below Figure 1 , Figure 1 A flowchart showing a method for processing large-sized high-precision optical parts of the present invention is shown. The processing method is used to process large-sized optical parts, wherein, referring to Figure 2 The optical component 1 is in the shape of a cube, and includes a first side surface 11, a second side surface 12, a third side surface 13, a fourth side surface 14 connected in sequence, and a first end surface 15 and a second end surface 16 arranged opposite to each other.

[0058] It is understandable that during processing, ring-polishing equipment will be used to process large-sized optical parts 1, but during the processing, the optical part 1 needs to be erected, that is, the first end face 15 and the second end face 16 of the optical part 1 need to be located above and below, and then the first end face 15 and the second end face 16 are processed. However, due to the large size of the optical part 1, after the optical part 1 is erected, the optical part 1 is very likely to shake and become unstable, which can easily deteriorate the processing effect, that is, the parameters of the first end face 15 and the second end face 16 after processing cannot meet the design requirements, and will reduce the safety and rationality of the processing, which results in the conventional processing method being unable to meet the processing requirements of large-sized optical parts 1.

[0059] Therefore, when processing the optical component 1, the processing method also uses a special positioning tool 2, which is used to position the large-sized optical component 1 when the two end faces of the optical component 1 are processed using the ring polishing equipment, see Figure 3-Figure 6 The positioning tool 2 includes a disc 21, a positioning plate 22 and a microcrystalline block 23. A avoidance hole 211 is provided at the center of the disc 21. The positioning plate 22 is detachably connected to the top of the disc 21. The microcrystalline block 23 is protrudingly arranged at the bottom of the disc 21.

[0060] Continue reading Figure 1 The processing method of the large-size high-precision optical component 1 comprises the following steps:

[0061] Step S1: Processing the first side surface 11, the second side surface 12, the third side surface 13 and the fourth side surface 14 to the first surface shape parameters;

[0062] Step S2: applying protective glue to the four sides of the optical component 1, placing the disc 21 on the platform, placing the microcrystalline block 23 between the platform and the disc 21, placing the second end face 16 of the optical component 1 downward into the avoidance hole 211, and then installing the positioning plate 22 to the disc 21, the positioning plate 22 abutting against the first side face 11, the second side face 12, the third side face 13 and the fourth side face 14, and filling the gap between the optical component 1 and the positioning plate 22 with yellow wax;

[0063] Step S3: grinding and polishing the first end surface 15 to a first surface shape parameter, ensuring that the first end surface 15 is perpendicular to the four side surfaces and the angle error is not greater than a first angle threshold;

[0064] Step S4: Place the first end surface 15 downward into the avoidance hole 211, and reinforce the four side surfaces by the positioning plate 22;

[0065] Step S5: grinding and polishing the second end surface 16 to the first surface shape parameter according to the method for processing the first end surface 15, ensuring that the second end surface 16 is parallel to the first end surface 15 and the parallel error is not greater than the first parallel threshold;

[0066] Step S6: Unmounting and cleaning the optical component 1.

[0067] The processing method first processes the four side faces of the optical component 1. When processing the first end face 15 and the second end face 16, a special positioning tool 2 is used to stably position the optical component 1. The positioning tool 2 can stably support the four side faces of the optical component 1 so that the large-sized optical component 1 can be stably maintained in a vertical state. The first end face 15 and the second end face 16 are then processed. Since the optical component 1 can be stably supported by the positioning tool 2, the stability of the first end face 15 and the second end face 16 during processing is improved, and high-precision processing of the first end face 15 and the second end face 16 is achieved. Therefore, through a reasonable process flow and the design of a special end face processing tool, the traditional optical cold processing method can be used to process large-sized and high-precision optical components 1.

[0068] In some embodiments, when grinding and polishing the first end surface 15 to the first surface shape parameter, the following steps are specifically included:

[0069] The optical component 1 and the first end face 15 are sanded by hand, the first dimension is removed by using coarse sand, and the second dimension is removed by using fine sand. While removing the dimension of the first end face 15, the inclination angle of the first end face 15 is continuously adjusted to ensure that the first end face 15 is perpendicular to the four side faces and the angle error is not greater than the first angle threshold;

[0070] The optical component 1 and the first end face 15 are polished as a whole, and the third dimension is removed by high-speed polishing using a ring polishing device. A comparator is used to detect the angles between the four side faces and the first end face 15. According to the detection values, the first end face 15 is polished at a low speed to the first surface parameter, and the first end face 15 is made perpendicular to the four side faces and the angle error is not greater than the first angle threshold.

[0071] Further, according to the detection value, the first end surface 15 is polished at a low speed to a first surface shape parameter, specifically including:

[0072] When the test value shows a sharp angle, increase the polishing pressure on the side of the sharp angle to remove more size on the side of the sharp angle;

[0073] When the test value shows a blunt angle, increase the polishing pressure on the side opposite to the sharp angle.

[0074] Further, according to the method for processing the first end surface 15, grinding and polishing the second end surface 16 to the first surface shape parameter specifically includes:

[0075] The positioning plate 22 and the second end surface 16 are sanded by hand, the first dimension is removed by using coarse sand, and the second dimension is removed by using fine sand. While removing the dimension of the second end surface 16, the inclination angle of the second end surface 16 is adjusted to ensure that the second end surface 16 is perpendicular to the four side surfaces and the angle error is not greater than the first angle threshold;

[0076] The positioning plate 22 and the second end face 16 are polished as a whole, and the third dimension is removed by high-speed polishing using a ring polishing device. A comparator is used to detect the angles between the four side faces and the second end face 16. Based on the detection values, the second end face 16 is polished at a low speed to the first surface parameter, and the second end face 16 is made perpendicular to the four side faces and the angle error is not greater than the first angle threshold.

[0077] Further, after the four sides are reinforced by the positioning plate 22, the following is further included:

[0078] The gap between the optical component 1 and the positioning plate 22 is filled with yellow wax.

[0079] Furthermore, after polishing the first end face 15 and the second end face 16 , the method further includes: chamfering the first end face 15 and the second end face 16 .

[0080] In some embodiments, when processing the second side surface 12, the following steps are specifically included:

[0081] The second side surface 12 is processed to the first surface shape parameter, the edge thickness difference is controlled to be no greater than the first thickness threshold, the angle between the second side surface 12 and the first side surface 11 is controlled to be 90°, and the angle error is controlled to be no greater than the first angle threshold.

[0082] In some embodiments, when processing the third side surface 13, the process specifically includes:

[0083] Taking the first side surface 11 as the reference plane, the third side surface 13 is processed to the first surface shape parameter, the edge thickness difference is controlled to be no greater than the first thickness threshold, the third side surface 13 and the first side surface 11 are controlled to be parallel, and the parallel error is controlled to be no greater than the first parallel threshold.

[0084] In some embodiments, when processing the fourth side surface 14, the process specifically includes:

[0085] Taking the second side surface 12 as the reference plane, the fourth side surface 14 is processed to the first surface shape parameter, the edge thickness difference is controlled to be no greater than the first thickness threshold, the fourth side surface 14 is controlled to be parallel to the second side surface 12, and the parallel error is controlled to be no greater than the first parallel threshold.

[0086] Furthermore, after processing the first side surface 11 , the second side surface 12 , the third side surface 13 and the fourth side surface 14 , the method further includes: chamfering the first side surface 11 , the second side surface 12 , the third side surface 13 and the fourth side surface 14 .

[0087] In some embodiments, the positioning tool 2 is used to position the optical component 1. Figure 2 The optical component 1 is in the shape of a cube, and includes a first side surface 11, a second side surface 12, a third side surface 13, a fourth side surface 14 connected in sequence, and a first end surface 15 and a second end surface 16 arranged opposite to each other.

[0088] See also Figure 3-Figure 6 The positioning tool 2 can adopt the following structure: the positioning tool 2 includes a disk 21, a positioning plate 22 and a microcrystalline block 23, wherein the disk 21 is used to be placed on the platform, and the center of the disk 21 is provided with an avoidance hole 211 that is adapted to the size of the first end face 15 and the second end face 16, the optical component 1 is inserted into the avoidance hole 211, and the avoidance hole 211 stops at the first side surface 11, the second side surface 12, the third side surface 13 and the fourth side surface 14.

[0089] See also Figure 6 The positioning plate 22 is detachably connected to the upper surface of the disk 21 , and the positioning plate 22 abuts against the first side surface 11 , the second side surface 12 , the third side surface 13 and the fourth side surface 14 .

[0090] The microcrystalline block 23 is protrudingly disposed on the bottom of the disk 21 , and is padded between the disk 21 and the platform, so that a first gap for accommodating the optical component 1 is provided between the disk 21 and the platform.

[0091] In some embodiments, see Figure 3-Figure 6The positioning plate 22 includes a first plate body 221 and a second plate body 222 that are detachably connected. The first plate body 221 is detachably set on the disk 21 by bolts. The second plate body 222 includes a top surface 223 and a bottom surface 224 relative to each other. The top surface 223 abuts on the first plate body 221 and is fixed by bolts. The bottom surface 224 abuts against the side of the optical component 1 and is perpendicular to the upper surface of the disk 21. The second plate body 222 is also provided with an observation hole 225 that passes through the top surface 223 and the bottom surface 224.

[0092] Furthermore, the microcrystalline block 23 is fixed to the bottom of the disk 21 by means of silicone bonding.

[0093] The following describes the processing method of the large-size and high-precision optical component 1 in the implementation method with reference to examples. The size of the finished product to be processed is 350mm×70mm×70mm, and the six surfaces of the optical component 1 are all polished. The surface shape PV of each surface is ≤1λ, and the angle requirements are: the angle between two adjacent surfaces = 90°±2″, the angle between two relative surfaces = 0°±2″, the smoothness: 40-20, and the material is microcrystalline. It should be noted that the surface shape detection mentioned in the present invention is all laser detection at 633nm, and ring polishing equipment is used for processing the first end face 15 and the second end face 16, and the first angle threshold is 2″, the first parallel threshold is 2″, the first dimension is 0.2mm, the second dimension is 0.08mm, the third dimension is 0.015mm, and the first thickness threshold is 0.005mm.

[0094] The processing flow is as follows:

[0095] (1) Processing the first side surface 11

[0096] Putting on the plate: Place the parts to be processed on the glass plate symmetrically in the center, with the first side 11 facing upwards, and then pour melted yellow wax on the plate. After the yellow wax solidifies, the parts to be processed can be fixed on the plate.

[0097] Sanding: reserve 0.3mm machining allowance for each surface to be processed. During the processing, first use W40 (coarse sand) to remove 0.2mm of the size and remove some large damage on the surface of the blank. Then use W14 (fine sand) to remove 0.08mm of the size to remove the damage left by the coarse sand and facilitate subsequent polishing.

[0098] Polishing: First use the ring polishing high polishing equipment to polish, remove the size of 0.015mm, and remove the sand holes of the frosted, so as to facilitate the low polishing. After the high polishing is completed, use the ring polishing low polishing equipment to polish, remove the remaining size of 0.005mm, and refine the surface shape and finish of the processed surface.

[0099] Lower plate: The first side surface 11 is coated with protective glue to protect the polished surface. The lower plate is placed in a freezer and the entire plate is refrigerated. The optical component 1 can be removed after the wax layer is invalidated.

[0100] Chamfer: The first side surface 11 has a chamfered protection angle to prevent parts from being bumped and chipped.

[0101] Cleaning: Use Paulick to remove the yellow wax residue on the optical parts 1, and use acetone and ethanol to remove waterproof glue and other contaminants.

[0102] (2) Processing the second side surface 12

[0103] Upper plate: Since all adjacent surfaces have a 90° angle accuracy requirement, the angle between the first side 11 and the second side 12 needs to be controlled to be 90°±2″ when processing the second side 12. This step uses a cuboid for auxiliary processing. The 90° angle accuracy of the cuboid has reached 2″, so this tooling can be used to correct the angle between the first side 11 and the second side 12. First, optically glue the first side 11 of the optical component 1 to the cuboid, and then optically glue the cuboid to the optical glue plate.

[0104] Sanding: Use W40 (coarse sand) to remove 0.2mm, and then use W14 (fine sand) to remove 0.08mm. The edge thickness difference needs to be controlled during the sanding process, and the deviation of the entire plate product cannot exceed 0.005mm.

[0105] Polishing: First use the ring polishing and high polishing equipment to polish, remove the size of 0.015mm, and remove the sand holes of the frosted, so as to facilitate the low polishing. After the high polishing is completed, use the ring polishing and low polishing equipment to polish, remove the remaining size of 0.005mm, and refine the surface shape and finish of the processed surface. The edge thickness difference also needs to be controlled ≤0.005mm during the polishing process to avoid the edge thickness difference affecting the angle of the product.

[0106] Lower plate: Apply protective glue to the polished surface to protect the polished surface. Use the method of knocking the lower plate to remove the plate and remove the optical component 1 from the bottom of the cuboid.

[0107] Chamfer: The second side has a 12-degree chamfer protection angle to prevent parts from being bumped and chipped.

[0108] Cleaning: Use acetone and ethanol to remove waterproof glue and other contaminants.

[0109] (3) Processing the third side surface 13

[0110] Upper plate: The first side surface 11 is the light-resist surface, and the third side surface 13 is the surface to be processed. Because the first side surface 11 and the second side surface 12 have been processed, they can be used as reference surfaces to directly process the surfaces opposite to them.

[0111] Sanding: Use W40 (coarse sand) to remove 0.2mm, and then use W14 (fine sand) to remove 0.08mm. The edge thickness difference needs to be controlled during the sanding process, and the deviation of the entire plate product cannot exceed 0.005mm.

[0112] Polishing: First use the ring polishing and high polishing equipment to polish, remove the size of 0.015mm, and remove the sand holes of the frosted, so as to facilitate the low polishing. After the high polishing is completed, use the ring polishing and low polishing equipment to polish, remove the remaining size of 0.005mm, and refine the surface shape and finish of the processed surface. The edge thickness difference also needs to be controlled ≤0.005mm during the polishing process to avoid the edge thickness difference affecting the angle of the product.

[0113] Lower plate: Apply protective glue on the polished surface, and knock and vibrate the lower plate after it dries.

[0114] Chamfer: The third side surface 13 has a chamfered protection angle.

[0115] Cleaning: Use acetone and ethanol.

[0116] (4) Processing the fourth side surface 14

[0117] The processing flow of the fourth side surface 14 is the same as the processing flow of the third side surface 13 .

[0118] (5) Processing the first end surface 15

[0119] Since the first end face 15 is processed using a ring-polishing device, the part needs to be stood up vertically for frosting and polishing. However, due to the large size and high center of gravity of the optical part 1, direct processing is unreasonable. In view of the processing requirements, we have designed a special positioning tool 2.

[0120] The positioning tooling 2 is divided into three parts. The middle disc 21 is a cast iron disc with a diameter of 280 mm. Its heavy weight can reduce the overall center of gravity during the processing. On it are 4 detachable and assembled positioning plates 22. In addition to the mounting screw holes, each positioning plate 22 also has a 50×60 observation hole 225 for detection during the processing. At the bottom, 8 microcrystalline blocks 23 are bonded with silicone, which increases the polishing area while also playing a supporting role.

[0121] Upper plate:

[0122] Apply protective glue to the four processed sides of the optical component 1. After the glue is dry, disassemble the tooling of the upper plate, place the disc 21 on the platform, and then put the optical component 1 to be processed in it, with the first end face 15 facing downward, and then assemble the four positioning plates 22. In order to ensure that the optical component 1 does not fall off during the processing, fill the gap between the optical component 1 and the positioning plate 22 with yellow wax, wait for it to cool and solidify, and then the upper plate can be completed.

[0123] Sanding: Sand the entire optical component 1 and the positioning plate 22 by hand, use W40 (coarse sand) to remove 0.2mm of the size, and then use W14 (fine sand) to remove 0.08mm of the size. During the sanding process, the angle needs to be manually adjusted, that is, while removing the size of the first end face 15, the inclination angle of the first end face 15 is continuously adjusted to ensure that the angle accuracy of the first end face 15 and the four processed side faces is within 10 seconds, which is helpful for the control of the angle accuracy of subsequent polishing.

[0124] Polishing: Polish the optical component 1 and the positioning plate 22 as a whole. First, use the ring polishing and high polishing equipment to remove 0.015mm of the size. Use the comparator to detect the angles of the four side faces and the first end face 15, and record the data. According to the actual value, the angle is refined in the low polishing. The edge with an acute angle is increased with pressure to make this side have more size. If the angle is an obtuse angle, the pressure is increased on the opposite side. The four angles are simultaneously repaired to 90°±2″. The surface shape, angle, and finish are qualified and the plate can be removed.

[0125] Lower plate: Apply protective glue to the processed surface, freeze the lower plate, put the positioning tool 2 and the optical component 1 into the freezer, and after freezing to make the wax ineffective, the positioning tool 2 can be disassembled and the optical component 1 can be removed.

[0126] Chamfer: The first end face has 15 chamfered protection angles.

[0127] Cleaning: Use Paulick to remove the yellow wax residue on the parts, and use acetone and ethanol to remove waterproof glue and other contaminants.

[0128] (6) Processing the second end surface 16

[0129] Mounting: The mounting method is the same as the first end face 15. Place the first end face 15 downward into the positioning tooling 2 and reinforce it.

[0130] Sanding: Sand the entire optical component 1 and the positioning plate 22 by hand, use W40 (coarse sand) to remove 0.2mm of the size, and then use W14 (fine sand) to remove 0.08mm of the size. During the sanding process, the angle needs to be manually adjusted, that is, while removing the size of the second end face 16, the inclination angle of the second end face 16 is continuously adjusted to ensure that the angle accuracy of the second end face 16 and the four processed side faces is within 10 seconds, which is helpful for the control of the angle accuracy of subsequent polishing.

[0131] Polishing: Polish the optical component 1 and the positioning plate 22 as a whole. First, use a ring-polishing and high-polishing device to remove 0.015mm of the size. Use a comparator to detect the angles of the four side faces and the second end face 16, and record the data. According to the actual value, fine-tune the angle in the low polishing. Increase the pressure on the edge with an acute angle to increase the size of this side. If the angle is an obtuse angle, increase the pressure on the opposite side, and repair the four angles to 90°±2″ at the same time. Compared with the processing of the first end face 15, the second end face 16 also needs to control the parallelism with the first end face 15. The second end face 16 is processed according to the actual angle of the first end face 15 to ensure that the parallelism of the two end faces is within 2″. The plate can be removed when the surface shape, angle, and smoothness are qualified.

[0132] Lower plate: Apply protective glue to the processed surface, freeze the lower plate, put the positioning tool 2 and the optical component 1 into the freezer, and after freezing to make the wax ineffective, the positioning tool 2 can be disassembled and the optical component 1 can be removed.

[0133] Chamfer: Provide a protective chamfer on the second end face 16.

[0134] Cleaning: Use Paulick to remove the yellow wax residue on the parts, and use acetone and ethanol to remove waterproof glue and other contaminants.

[0135] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for processing large-size and high-precision optical parts, characterized in that: The optical component is in the shape of a cube, and includes a first side surface, a second side surface, a third side surface, a fourth side surface connected in sequence, and a first end surface and a second end surface arranged oppositely; a positioning fixture is also provided, and the positioning fixture includes a disc, a positioning plate and a microcrystalline block, the center of the disc is provided with an avoidance hole, the positioning plate is detachably connected to the top of the disc, and the microcrystalline block is protrudingly arranged at the bottom of the disc; The processing method comprises: Processing the first side surface, the second side surface, the third side surface and the fourth side surface to first surface shape parameters; Apply protective glue to the four sides of the optical component for protection, place the disc on the platform, place the microcrystalline block between the platform and the disc, put the second end face of the optical component into the avoidance hole with the second end face facing downward, and then install the positioning plate to the disc, the positioning plate stops at the first side face, the second side face, the third side face and the fourth side face, and the four side faces are reinforced by the positioning plate; Frosting and polishing the first end surface to a first surface shape parameter to ensure that the first end surface is perpendicular to the four side surfaces and the angle error is not greater than a first angle threshold; Place the first end face downward into the avoidance hole, and reinforce the four side surfaces by the positioning plate; According to the method for processing the first end face, grinding and polishing the second end face to the first surface shape parameter, ensuring that the second end face is parallel to the first end face and the parallel error is not greater than a first parallel threshold; Remove the plate and clean the optical parts.

2. The method for processing large-size and high-precision optical parts according to claim 1, characterized in that: The grinding and polishing of the first end surface to the first surface shape parameters specifically include: The positioning plate and the first end surface are sanded by hand, the first dimension is removed by using coarse sand, and the second dimension is removed by using fine sand. While removing the dimension of the first end surface, the inclination angle of the first end surface is adjusted to ensure that the first end surface is perpendicular to the four side surfaces and the angle error is not greater than the first angle threshold; The positioning plate and the first end face are polished as a whole, and the third dimension is removed by high-speed polishing using a ring polishing device. A comparator is used to detect the angles between the four side faces and the first end face. According to the detection values, the first end face is polished at a low speed to the first surface parameter, and the first end face is made perpendicular to the four side faces and the angle error is not greater than the first angle threshold.

3. The method for processing large-size and high-precision optical parts according to claim 2, characterized in that: The step of polishing the first end surface to the first surface shape parameter at a low speed according to the detection value specifically includes: When the test value shows a sharp angle, increase the polishing pressure on the side of the sharp angle to remove more size on the side of the sharp angle; When the test value shows a blunt angle, increase the polishing pressure on the side opposite to the sharp angle.

4. The method for processing large-size and high-precision optical parts according to any one of claims 1 to 3, characterized in that: The method of processing the first end face, grinding and polishing the second end face to the first surface shape parameter specifically includes: Sand the positioning plate and the second end surface as a whole by hand, use coarse sand to remove the first dimension, and then use fine sand to remove the second dimension. While removing the dimension of the second end surface, adjust the inclination angle of the second end surface to ensure that the second end surface is perpendicular to the four side surfaces and the angle error is not greater than the first angle threshold; The positioning plate and the second end face are polished as a whole, and the third dimension is removed by high-speed polishing using a ring polishing device. A comparator is used to detect the angles between the four side faces and the second end face. According to the detection values, the second end face is polished at a low speed to the first surface parameters, and the second end face is made perpendicular to the four side faces and the angle error is not greater than the first angle threshold.

5. The method for processing large-size and high-precision optical parts according to claim 4, characterized in that: After the four sides are reinforced by the positioning plate, the method further comprises: The gap between the optical component and the positioning plate is filled with yellow wax.

6. The method for processing large-size and high-precision optical parts according to claim 4, characterized in that: After polishing the first end surface and the second end surface, the method further comprises: The first end surface and the second end surface are chamfered.

7. The method for processing large-size and high-precision optical parts according to claim 4, characterized in that: The processing of the second side surface specifically includes: Process the second side surface to the first surface shape parameters, control the edge thickness difference to be no greater than the first thickness threshold, control the angle between the second side surface and the first side surface to be 90°, and the angle error to be no greater than the first angle threshold.

8. The method for processing large-size and high-precision optical parts according to claim 4, characterized in that: The processing of the third side surface specifically includes: Taking the first side surface as a reference plane, the third side surface is processed to the first surface shape parameter, the edge thickness difference is controlled to be no greater than a first thickness threshold, the third side surface is controlled to be parallel to the first side surface, and the parallel error is controlled to be no greater than a first parallel threshold.

9. The method for processing large-size and high-precision optical parts according to claim 4, characterized in that: The processing of the fourth side surface specifically includes: Taking the second side surface as the reference plane, the fourth side surface is processed to the first surface shape parameter, the edge thickness difference is controlled to be no greater than the first thickness threshold, the fourth side surface is controlled to be parallel to the second side surface, and the parallel error is controlled to be no greater than the first parallel threshold.

10. The method for processing large-size and high-precision optical parts according to claim 4, characterized in that: After processing the first side surface, the second side surface, the third side surface and the fourth side surface, the method further includes: chamfering the first side surface, the second side surface, the third side surface and the fourth side surface.

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