A large-diameter part low-scratch-probability precision annular polishing tool and polishing method

Abstract

The application discloses a large-diameter part low-scratching-probability precision annular polishing tool and a polishing processing method, and belongs to the field of optical processing; a special tool, namely, an annular polishing separator assembly, is designed, the annular polishing separator assembly comprises a bottom plate made of glass and located at the bottom and an upper plate made of aluminum alloy and fixedly bonded to the bottom plate, the overall thickness of the annular polishing separator assembly is not less than 30 mm, the annular polishing separator assembly can replace a workpiece ring + separator combined processing scheme of a traditional annular polishing machine, the workpiece caliber of the traditional medium-caliber annular polishing machine is increased, and thus the annular polishing processing of a large-diameter part with an overall size of 600 mm-660 mm can be realized on the medium-caliber annular polishing machine. Meanwhile, the introduction of the flat glass bottom plate reduces the scratches introduced in the annular polishing process, the bonding of the glass bottom plate and the aluminum alloy upper plate increases the rigidity of the combined assembly, and the risk of part scrapping caused by the fragmentation of the pure glass separator in the processing process is avoided.

Description

Technical Field

[0001] This invention relates to the field of optical processing, specifically to a precision annular polishing fixture and polishing method for large-diameter parts with low scratch probability. Background Technology

[0002] The infrared window components are made of multispectral zinc sulfide, processed through chemical vapor deposition and hot isostatic pressing. Multispectral zinc sulfide is relatively soft and prone to scratches during processing. The maximum size of these components exceeds 600mm, exhibiting poor rigidity and susceptibility to deformation, while also requiring high precision. Traditional medium-diameter ring polishing machines (typically with a working disc diameter of 1.6m) are suitable for processing components up to 600mm in diameter, but struggle to process those larger. Large-diameter ring polishing machines (typically with a working disc diameter of 1.8m / 2.5m) are expensive, inconvenient to operate, and require a large footprint, thus limiting the high-precision processing of large-diameter infrared window components.

[0003] Given that medium-diameter ring polishing machines are not applicable and the use of large-diameter ring polishing machines is limited by cost and other factors, existing methods for finishing large-diameter infrared window parts with a maximum size greater than 600mm generally use single-axis polishing. This process is prone to scratches, and the machining accuracy cannot meet the latest precision requirements of the parts.

[0004] Therefore, how to use a traditional medium-diameter ring polisher to achieve precision machining of infrared window parts with a diameter of 600mm or more and reduce the probability of scratches on the parts is a topic worthy of our research. Summary of the Invention

[0005] The technical problem to be solved: To overcome the shortcomings of existing technologies, this invention provides a precision ring polishing fixture and polishing method for large-diameter parts with low scratch probability. By designing a dedicated fixture - a ring polishing separator assembly - it is adapted to a traditional medium-diameter ring polishing machine, thereby increasing the diameter of parts that can be processed by the traditional medium-diameter ring polishing machine and reducing the probability of scratches during processing. Furthermore, the polishing method of this invention meets the high-precision polishing requirements of large-diameter infrared window parts.

[0006] The technical solution of this invention is: a precision annular polishing fixture for large-diameter parts with low scratch probability, which is an annular polishing separator assembly, used to assemble the parts to be processed and place them on the polishing mold of the annular polishing machine for annular polishing processing. The annular polishing separator assembly includes: The base plate is a disc-shaped flat glass for windows, with a first through hole in the center. The size of the first through hole is adapted to the part to be processed, and the part to be processed is placed inside the first through hole. The upper plate is a disc-shaped structure, coaxially fixed and bonded to the base plate. The outer diameter of the upper plate is the same as that of the base plate. A second through hole is provided in the middle of the upper plate. The second through hole is the same size as the first through hole and the outline is aligned. The second through hole is used to avoid the parts to be processed. The second through hole and the first through hole together form the mounting hole of the ring-throw separator assembly. The bottom end face of the base plate is used to contact the polishing mold of the ring polisher, and the outer diameter wall of the upper plate is used to contact the caliper drive wheel of the ring polisher.

[0007] A further technical solution of the present invention is as follows: the base plate is provided with a plurality of first operating holes around the wall of the first through hole, and the first operating holes are connected to the first through hole; the inner side of the upper plate is provided with a plurality of second operating holes around the second through hole, and the second operating holes are connected to the second through hole; the second operating holes and the first operating holes have the same structure and are coaxially corresponding to each other, and the two together form a tooling operating hole, which is used to avoid the operator's hand when the operator holds the part to be processed and puts it into the mounting hole.

[0008] A further technical solution of the present invention is: the upper plate is an assembly comprising multiple upper plate units made of aluminum alloy, the multiple upper plate units being sequentially fixed and spliced ​​around the same circumference on a plane to form a disc-shaped upper plate; each upper plate unit has an inner recess, and the inner recesses of multiple upper plate units are spliced ​​together to form a second through hole; the second operating hole is located at the middle position of the inner side of the upper plate unit.

[0009] A further technical solution of the present invention is: the upper plate unit has a weight reduction groove with an open side on its upper surface facing away from the bottom plate. The weight reduction groove is used to reduce the weight of the upper plate unit. Multiple threaded holes are provided in the weight reduction groove near the open end. The threaded holes are used to install connecting pieces. When two adjacent upper plate units are spliced ​​together, the open ends of their weight reduction grooves are connected, and the two adjacent upper plate units are fixedly connected by connecting pieces and fastening screws.

[0010] A further technical solution of the present invention is that the total axial thickness of the ring-shaped separator assembly is not less than 30 mm.

[0011] A precision annular polishing method for large-diameter parts with low scratch probability, the method using the aforementioned annular polishing separator assembly for part clamping includes the following steps: A ring-shaped polishing mold base is formed by pouring tar onto the marble disc of the ring polishing machine; the flatness of the upper surface of the polishing mold base is initially adjusted for a certain period of time using the correction disc 5 provided with the ring polishing machine; and a groove is cut into the upper surface of the polishing mold base to obtain the polishing mold. The surface of the polishing mold is trimmed and polished using a calibration disc. During trimming and polishing, the test disc is installed in the ring polishing separator assembly as the part to be processed. The ring polishing separator assembly with the test disc and the calibration disc are placed on the polishing mold and respectively placed in the corresponding caliper positions of the ring polishing machine. After adding polishing liquid to the polishing mold, the ring polishing machine is started to trim and polish the surface of the polishing mold. The surface profile of the test plate is measured using a laser interferometer. If the surface profile of the test plate is better than 0.8λ, the surface profile trimming of the polishing mold ends; otherwise, the surface profile trimming of the polishing mold continues until the requirements are met. Here, λ is the unit of surface profile accuracy and is the wavelength of the helium-neon laser used in the interferometer. Remove the test plate and install the part to be processed into the ring polishing separator assembly. Place the ring polishing separator assembly containing the part to be processed and the calibration plate on the polishing mold and place them in the corresponding caliper positions of the ring polishing machine. After adding polishing fluid to the polishing mold, start the ring polishing machine to perform ring polishing of the part. During the ring polishing process, check the surface shape of the part at set intervals using a laser interferometer until the surface shape of the part meets the requirements.

[0012] A further technical solution of the present invention is as follows: the method of casting an annular polishing mold base by asphalt casting is to attach a ring of kraft paper around the circumference of a marble plate, place a metal bucket in the center of the marble plate, pour hot melted asphalt into the annular area between the metal bucket and the kraft paper, and after the asphalt cools and solidifies, remove the metal bucket and the kraft paper, and chamfer the edges of the inner and outer rings of the solidified structure to obtain the annular polishing mold base.

[0013] A further technical solution of the present invention is as follows: the method of slotting the upper surface of the polishing mold base is as follows: firstly, a metal grooving cutter is used to uniformly open a plurality of longitudinal grooves and a plurality of transverse grooves on the upper surface of the polishing mold base. The longitudinal grooves and transverse grooves are perpendicular to each other and have the same groove shape. The spacing between adjacent grooves in the same direction is 80mm, the groove width is 5mm, and the groove depth is 10mm. Then, a plurality of concentric annular fine grooves are opened on the upper surface of the polishing mold base using a metal grooving cutter.

[0014] A further technical solution of the present invention is: when measuring the surface profile of the test plate by a laser interferometer, the surface profile within a φ150mm diameter at the center, edge, and four corners of the test plate is measured every 12 hours. The surface profile within the detected range is better than 0.8λ, that is, the surface profile of the test plate is better than 0.8λ.

[0015] A further technical solution of the present invention is: when inspecting the surface shape of the processed part by a laser interferometer, the surface shape within a φ150mm diameter at the center, edge, and four corners of the part is measured every 12 hours. If the design requirements are met, the surface shape of the part is considered to meet the requirements.

[0016] The beneficial effects of this invention are as follows: By designing a precision annular polishing fixture for large-diameter parts with a low probability of scratches, this invention enables the precision machining of infrared window parts with a diameter of 600mm or more (maximum size approximately between 600mm and 660mm) on a medium-diameter annular polishing machine with a working disc diameter of 1.6m, while reducing the probability of scratches on the parts. This invention also features an annular polishing separator assembly consisting of a base plate and an upper plate. This assembly can replace the traditional workpiece ring + separator machining scheme of an annular polishing machine. It is placed directly on the polishing mold of the annular polishing machine, and the outer diameter wall of the upper plate of the annular polishing separator assembly directly contacts the caliper drive wheel of the annular polishing machine, eliminating the need for a workpiece ring. Based on a traditional workpiece ring wall thickness of 30mm, using the annular polishing separator assembly of this application can increase the diameter of parts that can be processed by the same annular polishing machine by more than 60mm. The reason is that the total axial thickness of the ring polishing separator assembly, which combines the base plate and the upper plate in this application, is no less than 30mm, allowing it to directly contact the caliper's drive wheel. The drive wheel can directly rotate the ring polishing separator assembly, thereby rotating the part. In contrast, in the traditional workpiece ring + separator solution, the separator thickness is insufficient to contact the caliper's drive wheel. The caliper's drive wheel needs to rotate the workpiece ring, and then the separator drives the part to rotate within the workpiece ring to achieve polishing. The combined separator device of this invention can directly drive the part to rotate counterclockwise on the surface of the polishing mold, without the need for a workpiece ring.

[0017] The bottom of the ring polishing separator assembly of this invention contacts the polishing mold via a base plate made of window-grade flat glass. The window-grade flat glass offers good rigidity and flatness, significantly reducing the probability of scratches on parts during processing compared to the PTFE separators used in existing workpiece ring + separator solutions. The combined base plate and top plate separation device prevents larger particles or fragments from directly contacting the workpiece surface, further reducing the risk of scratches. Comparison with existing workpiece ring + separator solutions, based on processing data from 50 parts, the number of scratches decreased from 38 to 8 after adopting the ring polishing separator assembly of this invention.

[0018] In this invention, the upper plate is made of aluminum alloy, which is lightweight, and the weight is further reduced through a weight-reducing groove design. The upper plate is designed with multiple unit splicing, allowing each unit to be processed independently. Unit-based processing helps reduce the difficulty of upper plate manufacturing, improves the flatness of the surface, and achieves a flatness of better than 0.1mm on the lower end face of the upper plate, meeting the assembly requirements with the base plate and saving processing costs. Simultaneously, the base plate made of window flat glass and the aluminum alloy upper plate are bonded together, ensuring strength requirements while avoiding the risk of the glass base plate breaking.

[0019] The present invention provides a self-made asphalt polishing mold. By opening longitudinal grooves, transverse grooves, and annular fine grooves on the polishing mold, the polishing liquid is evenly dispersed, the chip removal capacity is enhanced, the polishing pressure is balanced and heat dissipation is achieved, the surface convergence time of the polishing mold is shortened, the surface stabilization time of the polishing mold is extended, and the polishing effect is effectively improved.

[0020] In this invention, a test plate with the same shape as the part is used. The local surface profile of the test plate at its center, edges, and four corners (φ150mm) is tested to determine if the polishing mold meets the requirements. This provides accurate feedback on the part's processing effect. When the test plate's surface profile accuracy meets the requirements, seamless connection in part processing can be achieved. Testing the local surface profile at the center, edges, and four corners of the test plate to judge the polishing mold's performance avoids reliance on large-aperture interferometers, thus ensuring the quality of the circumferential polished surface of the part to be processed. Simultaneously, during the circumferential polishing process, a correction plate is continuously placed on the polishing mold for finishing, ensuring the flatness of the polishing mold surface. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of a precision annular polishing fixture for large-diameter parts with low scratch probability according to the present invention. Figure 2 This is an isometric view of the precision annular polishing fixture for low scratch probability of large-diameter parts according to the present invention, in conjunction with the part to be processed. Figure 3 This is a top view of the precision annular polishing fixture for large-diameter parts with low scratch probability, and the workpiece to be processed, according to the present invention. Figure 4 This is a schematic diagram of the base plate structure in this invention; Figure 5 This is a schematic diagram of the upper plate structure in this invention; Figure 6 This is a schematic diagram of the upper plate unit in this invention; Figure 7 This is a flowchart of a precision annular polishing method for large-diameter parts with low scratch probability according to the present invention. Figure 8 This is a schematic diagram of the metal grooving tool structure used in this invention; Figure 9 A schematic diagram of the structure after the longitudinal and transverse grooves have been machined for the polishing mold; Figure 10A schematic diagram of the structure after the fine grooves have been machined for the polishing mold; Figure 11 A three-dimensional structural diagram of the polishing mold after the fine grooves have been machined; Figure 12 This is a schematic diagram of the part processing procedure in the method of the present invention; Figure 13 This is a schematic diagram of the structure of the ring-throw separator assembly of the present invention with a crossbeam added for use in a single-axis machine. In the diagram: 1. Ring-shaped separator assembly, 1-1. Base plate, 1-11. First through hole, 1-12. First operating hole, 1-2. Top plate, 1-21. Second through hole, 1-22. Second operating hole, 1-23. Top plate unit, 1-24. Recessed part, 1-25. Weight reduction groove, 1-3. Mounting hole, 1-4. Tooling operating hole, 1-5. Connecting piece, 2. Polishing mold, 2-1. Longitudinal groove, 2-2. Transverse groove, 2-3. Fine groove, 3. Part, 4. Caliper drive wheel, 5. Caliper disc, 6. Caliper, 7. Crossbeam. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1 An embodiment of the precision annular polishing fixture for large-diameter parts with low scratch probability according to the present invention, such as... Figures 1-3 As shown, the fixture is an improved ring polishing separator assembly 1, used to assemble the part 3 to be processed and place it on the polishing mold 2 of the ring polishing machine for ring polishing. The fixture includes a base plate 1-1 and an upper plate 1-2.

[0025] See also Figure 4 The base plate 1-1 is a disc-shaped flat glass panel for windows. The flat glass material of the base plate 1-1 provides excellent rigidity and flatness, with a flatness better than 0.02mm, which greatly reduces the probability of scratches on part 3 during processing. For example... Figure 4 As shown, the base plate 1-1 has a first through hole 1-11 at its center. The size of the first through hole 1-11 is adapted to the part 3 to be processed, and the part 3 to be processed is placed inside the first through hole 1-11. In this embodiment, the part 3 to be processed is a square plate, and the first through hole 1-11 adopts a square hole structure. In order to effectively improve the edge collapse phenomenon of part 3 during processing, in this embodiment, the size of the first through hole 1-11 with square hole structure is slightly larger than the outer shape of part 3 with square plate structure, and preferably the single-sided gap is 5mm.

[0026] See also Figure 5 The upper plate 1-2 is also a disc-shaped structure, coaxially fixedly bonded to the base plate 1-1. The outer diameter of the upper plate 1-2 is the same as that of the base plate 1-1. A second through hole 1-21 is provided in the middle of the upper plate 1-2. The second through hole 1-21 is the same size as the first through hole 1-11 and its outline is aligned. The second through hole 1-21 is used to avoid the part 3 to be processed. In this embodiment, the second through hole 1-21 is a square hole, and its four inner walls are completely aligned with the four inner walls of the first through hole 1-11. After the upper plate 1-2 is fixed to the base plate 1-1, the second through hole 1-21 and the first through hole 1-11 together form the mounting hole 1-3 of the ring-throw separator assembly 1, and the part 3 to be processed is placed in the mounting hole 1-3.

[0027] The ring polishing separator assembly 1 is used in conjunction with the ring polishing machine. During use, the lower end face of the base plate 1-1 contacts the polishing mold 2 of the ring polishing machine, and the outer diameter wall of the upper plate 1-2 directly contacts the caliper drive wheel 4 of the ring polishing machine. By placing the part to be processed into the mounting hole 1-3, ensuring that the surface to be polished contacts the polishing mold 2, the ring polishing machine can be started to directly polish the part 3. In this embodiment, the total axial thickness of the ring polishing separator assembly 1, consisting of the base plate 1-1 and the upper plate 1-2, is not less than 30mm to ensure that the outer diameter wall of the upper plate 1-2 can contact the caliper drive wheel 4.

[0028] like Figure 4 , Figure 5 As shown, to facilitate the placement of part 3 into the mounting hole 1-3, this embodiment provides four first operating holes 1-12 around the wall of the first through hole 1-11 on the base plate 1-1. The first operating holes 1-12 are connected to the first through hole 1-11, forming an outward expansion of the first through hole 1-11. Similarly, four second operating holes 1-22 are provided around the second through hole 1-21 on the inner side of the upper plate 1-2. The second operating holes 1-22 are connected to the second through hole 1-21, also forming an outward expansion of the second through hole 1-21. The second operating holes 1-22 and the first operating holes 1-12 have the same structure and are coaxially corresponding. Together, they form the tooling operating hole 1-4, which is used to avoid obstructing the operator's hands when holding the part 3 to be processed and placing it into the mounting hole 1-3. The minimum distance from the outer edge of the tooling operation hole 1-4 to the outer diameter of the ring-throw separator assembly 1 is 35mm to ensure the strength requirements of the ring-throw separator assembly 1 and to prevent breakage at the tooling operation hole 1-4 during processing.

[0029] like Figure 6As shown, to facilitate processing and ensure the flatness of the lower end face of the upper plate 1-2 is better than 0.1mm, so that it is firmly bonded to the upper end face of the base plate 1-1 and the square holes at their centers are coaxially aligned, in this embodiment, the upper plate 1-2 is an assembly comprising four aluminum alloy upper plate units 1-23. The four upper plate units 1-23 have identical structures and are sequentially fixed and spliced ​​around the same circumference on a plane to form a disc-shaped upper plate, with each upper plate unit 1-23 occupying a corner of the upper plate 1-2. Each upper plate unit 1-23 has a recess 1-24 on its inner side for a second operating hole 1-22 (one-quarter inner diameter). The recesses 1-24 of the four upper plate units are spliced ​​together to form a second through hole 1-21. The second operating hole 1-22 of the upper plate 1-2 is located at the middle of the inner side of each upper plate unit 1-23.

[0030] When the four upper plate units 1-23 are assembled, adjacent upper plate units 1-23 are fixedly connected by a connecting piece 1-5. Simultaneously, to reduce weight, two concave weight-reducing grooves 1-25 with one open side are provided on the upper surface of the upper plate unit 1-23 facing away from the base plate 1-1. The two weight-reducing grooves 1-25 are symmetrically arranged on both sides of the second operating hole 1-22. Multiple threaded holes are provided in the weight-reducing grooves 1-25 near the open end for installing the connecting piece 1-5. When two adjacent upper plate units 1-23 are assembled, the open ends of their weight-reducing grooves 1-25 are aligned, and the two adjacent upper plate units 1-23 are fixedly connected by the connecting piece 1-5 and fastening screws. The connecting piece 1-5 is a metal sheet, and both ends are fixedly connected to the corresponding threaded holes of the upper plate unit 1-23 by fastening screws, thus achieving the splicing and fixing of adjacent upper plate units 1-23. In this embodiment, each upper plate unit 1-23 and the bottom plate 1-1 are positioned by pins and glued together, making the fixation more secure and reliable.

[0031] The ring polishing separator assembly 1, consisting of the base plate 1-1 and the upper plate 1-2, has a total thickness of not less than 30mm. It can replace the traditional workpiece ring + separator processing scheme of a ring polishing machine, increasing the diameter of parts that the ring polishing machine can process. Based on a traditional workpiece ring wall thickness of 30mm, using the ring polishing separator assembly of this application can increase the diameter of parts that can be processed by the same ring polishing machine by more than 60mm. By using the ring polishing separator assembly 1 of this embodiment, a medium-diameter ring polishing machine with a working disc diameter of 1.6m can achieve high-precision processing of 660mm diameter infrared multispectral zinc sulfide parts. Simultaneously, the base plate 1-1 uses a high-flatness window flat glass substrate, reducing scratches introduced during the ring polishing process. The bonding of the glass substrate to the aluminum alloy upper plate 1-2 increases the rigidity of the assembly, avoiding the risk of parts being scrapped due to breakage of the pure glass separator during processing.

[0032] It should be noted that the ring-polishing separator assembly 1 of the present invention can also be applied to large-diameter ring polishers, further increasing the diameter of parts that can be processed by large-diameter ring polishers. Meanwhile, as... Figure 13 As shown, the ring polishing separator assembly 1 of the present invention, in addition to being used in a ring polishing machine, can also be used in conjunction with a single-axis machine by adding two crossbeams 7 to achieve pressureless polishing. Two crossbeams 7 are cross-fixed on the upper plate 1-2 of the ring polishing separator assembly 1. The two ends of the crossbeams 7 are fixedly connected to the upper plate 1-2, and the middle of the crossbeams 7 is connected to the iron pen of the single-axis machine. The part 3 is placed in the mounting holes 1-3 of the ring polishing separator assembly 1 and placed on the polishing mold of the single-axis machine. In this structure, the pressure of the single-axis machine is applied to the ring polishing separator assembly 1 through the two crossbeams 7, avoiding direct application to the part 3, thus achieving pressureless polishing and improving the polished surface quality of the part 3.

[0033] Example 2 This embodiment provides a precision ring polishing method for large-diameter parts with low scratch probability. The method uses the ring polishing separator assembly 1 from Embodiment 1 to clamp the part 3, thereby achieving the polishing process. This embodiment selects a 470×470×14mm multispectral zinc sulfide square blank for processing.

[0034] like Figure 7 As shown, the processing method includes the following steps: Step 1. Cast tar onto the marble disc of the ring polishing machine to create a ring-shaped polishing mold base.

[0035] The specific method is as follows: attach a ring of kraft paper around the circumference of the marble disc of the 1.6m working disc diameter ring polisher, with the kraft paper extending 100mm above the marble disc. Place a cylindrical metal bucket with an outer diameter of 300mm in the center of the marble disc. Pour 30kg of 60# polishing tar into the annular area between the metal bucket and the kraft paper. The tar is melted using heating equipment. The tar pouring thickness is 35-45mm. Then let it stand to cool.

[0036] When pouring asphalt, the speed of the ring polisher should not exceed 1 r / min, and after pouring, it should be left to cool for at least 15 hours.

[0037] After the asphalt cools and solidifies, remove the metal bucket and kraft paper. Use a scraper to chamfer the edges of the inner and outer rings of the formed annular structure to obtain the annular polished mold base. During chamfering, the chamfering of the outer circumference should be no less than C20, and the chamfering of the inner hole circumference should be no less than C10.

[0038] Step 2. Use the correction disc 5 provided with the ring polisher to initially polish the upper surface of the polishing mold substrate to meet the flatness requirements. Using the correction disc trolley (the tool normally used to place the correction disc 5), move the correction disc 5 to the upper surface of the polishing mold substrate, add polishing fluid to the substrate, and start the ring polisher to initially polish the upper surface of the polishing mold substrate to meet the preliminary flatness requirements. The initial flatness polishing time should be no less than 40 hours to ensure the flatness requirements are met.

[0039] Step 3. Groove the upper surface of the polishing mold base to obtain polishing mold 2.

[0040] like Figures 8-11 As shown, the specific method is as follows: First, a metal grooving cutter is used to evenly open multiple longitudinal grooves 2-1 and multiple transverse grooves 2-2 on the upper surface of the polishing mold substrate. The longitudinal grooves 2-1 and transverse grooves 2-2 are perpendicular to each other and have the same groove shape. The groove spacing is 80mm, the groove width is 5mm, and the groove depth is 10mm. The structure of the metal grooving cutter is as follows. Figure 8 As shown, during processing, a rectangular metal strip no shorter than 1.6m is used to position and guide the metal grooving cutter. The cutter cuts grooves from the edge of the polishing mold base towards the center and then to the other edge, creating one groove at a time. This process is repeated multiple times to form multiple transverse grooves 2-2 spaced 80mm apart. Then, perpendicular to the transverse grooves 2-2, grooves are cut from the edge of the polishing mold base towards the center and then to the other edge, completing the processing of multiple longitudinal grooves 2-1. After the longitudinal grooves 2-1 and transverse grooves 2-2 are completed, multiple concentric annular fine grooves 2-3 are created on the upper surface of the polishing mold base using the metal grooving cutter. When creating the fine grooves 2-3, the metal grooving cutter is placed radially perpendicular to the upper surface of the polishing mold base. The ring polishing machine is started to rotate the polishing mold base, and the serrated tip of the metal grooving cutter processes multiple concentric annular fine grooves 2-3 on the polishing mold base. The depth of the fine grooves 2-3 is less than that of the longitudinal grooves 2-1 and transverse grooves 2-2. After grooving, the polishing mold 2 is obtained. By slotting the upper surface of the polishing mold base, the polishing liquid is evenly dispersed, enhancing the chip removal capacity, helping to balance the polishing pressure and achieve heat dissipation, and effectively improving the polishing effect.

[0041] Step 4. Polish the surface of polishing mold 2 using a calibration disc.

[0042] During the surface finishing of polishing mold 2, the calibration disc 5 is moved to the upper surface of polishing mold 2 using a calibration disc trolley and placed in the caliper 6 position of the ring polisher. The test disc piece, serving as the part to be processed 3, is installed in the ring polisher separator assembly 1 and placed in another caliper 6 position of the ring polisher. For example... Figure 12 As shown, the polishing mold 2 of the ring polisher has three stations above it. Each station is equipped with a caliper 6, and a caliper drive wheel 4 is located on one side of the caliper 6. The caliper drive wheel 4 drives the placement component at that station to rotate. After the calibration disc 5 and the ring polishing separator assembly 1 with the test disc are placed in place, polishing fluid is added to the polishing mold 2, and the ring polisher is started to polish the surface of the polishing mold. The purpose of the test disc is to evaluate whether the surface of the polishing mold 2 has been properly polished by examining the surface shape of the test disc.

[0043] Step 5. Check the surface shape of the test piece.

[0044] During the surface finishing process of polishing mold 2, the surface profile within a φ150mm diameter at the center, edge, and four corners of the test piece is measured every 12 hours using a laser interferometer. If the RMS of the surface profile within the measured range is better than 0.8λ, indicating that the surface profile of the test piece is better than 0.8λ, the surface finishing of polishing mold 2 ends. Otherwise, step 4 continues with the surface finishing of the polishing mold until the requirements are met. Here, λ is the unit of surface profile accuracy and is the wavelength of the helium-neon laser used in the interferometer, λ = 632.8nm. A surface profile better than 0.8λ indicates that the surface finishing of polishing mold 2 is complete and the formal polishing process for part 3 can begin.

[0045] Step 6. Machining the parts.

[0046] Once the surface of polishing mold 2 has been properly polished, remove the test disc from the ring polishing separator assembly 1, place part 3 inside, and continuously keep the calibration disc 5 in the clamp 6 position on polishing mold 2. After adding polishing fluid to polishing mold 2, start the ring polishing machine to ring polish the part. During the ring polishing process, check the surface of part 3 at set intervals using a laser interferometer until the surface of part 3 meets the requirements. Retaining the calibration disc 5 during processing allows for continuous refining of the surface of polishing mold 2.

[0047] When inspecting the three-sided profile of the machined part using a laser interferometer, the profile within a φ150mm diameter at the center, edge, and four corners of the part is measured every 12 hours. If the design requirements are met, i.e. the three-sided profile of the part meets the requirements, the machining is completed.

[0048] If the surface shape does not meet the requirements during the polishing process, steps 4 and 5 can be repeated. The surface shape of polishing mold 2 can be repaired and polished again using a calibration disc, and a test disc part can be used until the surface shape of the test disc part meets the requirements before processing part 3.

[0049] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A precision annular polishing fixture for large-diameter parts with low scratch probability, comprising an annular polishing separator assembly, used to assemble the parts to be processed and place them on the polishing mold of an annular polishing machine for annular polishing processing, characterized in that, The ring-jet separator assembly includes: The base plate is a disc-shaped flat glass for windows, with a first through hole in the center. The size of the first through hole is adapted to the part to be processed, and the part to be processed is placed inside the first through hole. The upper plate is a disc-shaped structure, coaxially fixed and bonded to the base plate. The outer diameter of the upper plate is the same as that of the base plate. A second through hole is provided in the middle of the upper plate. The second through hole is the same size as the first through hole and the outline is aligned. The second through hole is used to avoid the parts to be processed. The second through hole and the first through hole together form the mounting hole of the ring-throw separator assembly. The bottom end face of the base plate is used to contact the polishing mold of the ring polisher, and the outer diameter wall of the upper plate is used to contact the caliper drive wheel of the ring polisher.

2. The precision annular polishing fixture for large-diameter parts with low scratch probability according to claim 1, characterized in that, The base plate has multiple first operating holes around the wall of the first through hole, and the first operating holes are connected to the first through hole; the inner side of the upper plate has multiple second operating holes around the second through hole, and the second operating holes are connected to the second through hole; the second operating holes and the first operating holes have the same structure and are coaxially corresponding to each other, and the two together form a tooling operating hole, which is used to avoid the operator's hand when the operator holds the part to be processed and puts it into the mounting hole.

3. The precision annular polishing fixture for large-diameter parts with low scratch probability according to claim 1, characterized in that, The upper plate is an assembly comprising multiple upper plate units made of aluminum alloy. The multiple upper plate units are sequentially fixed and spliced ​​around the same circumference on a plane to form a disc-shaped upper plate. Each upper plate unit has an inner recess, and the inner recesses of multiple upper plate units are spliced ​​together to form a second through hole. The second operating hole is located in the middle of the inner side of the upper plate unit.

4. The precision annular polishing fixture for large-diameter parts with low scratch probability according to claim 3, characterized in that, The upper plate unit has a weight-reducing groove with an open side on its upper surface facing away from the bottom plate. The weight-reducing groove is used to reduce the weight of the upper plate unit. There are multiple threaded holes in the weight-reducing groove near the open end. The threaded holes are used to install connecting plates. When two adjacent upper plate units are spliced ​​together, the open ends of their weight-reducing grooves are connected, and the two adjacent upper plate units are fixedly connected by connecting plates and fastening screws.

5. The precision annular polishing fixture for large-diameter parts with low scratch probability according to claim 1, characterized in that, The total axial thickness of the ring-shaped separator assembly shall not be less than 30 mm.

6. A method for precision annular polishing of large-diameter parts with low scratch probability, characterized in that, This method uses the ring-jet separator assembly according to any one of claims 1-5 for part clamping, and includes the following steps: A ring-shaped polishing mold base is formed by pouring tar onto the marble disc of the ring polishing machine; the flatness of the upper surface of the polishing mold base is initially adjusted for a certain period of time using the correction disc that comes with the ring polishing machine; and then grooves are cut into the upper surface of the polishing mold base to obtain the polishing mold. The surface of the polishing mold is trimmed and polished using a calibration disc. During trimming and polishing, the test disc is installed in the ring polishing separator assembly as the part to be processed. The ring polishing separator assembly with the test disc and the calibration disc are placed on the polishing mold and respectively placed in the corresponding caliper positions of the ring polishing machine. After adding polishing liquid to the polishing mold, the ring polishing machine is started to trim and polish the surface of the polishing mold. The surface profile of the test plate is measured using a laser interferometer. If the surface profile of the test plate is better than 0.8λ, the surface profile trimming of the polishing mold ends; otherwise, the surface profile trimming of the polishing mold continues until the requirements are met. Here, λ is the unit of surface profile accuracy and is the wavelength of the helium-neon laser used in the interferometer. Remove the test plate and install the part to be processed into the ring polishing separator assembly. Place the ring polishing separator assembly containing the part to be processed and the calibration plate on the polishing mold and place them in the corresponding caliper positions of the ring polishing machine. After adding polishing fluid to the polishing mold, start the ring polishing machine to perform ring polishing of the part. During the ring polishing process, check the surface shape of the part at set intervals using a laser interferometer until the surface shape of the part meets the requirements.

7. The polishing method according to claim 6, characterized in that, The method of casting a ring-shaped polishing mold base by pouring tar is as follows: a ring of kraft paper is pasted around the circumference of a marble plate, a metal bucket is placed in the center of the marble plate, and hot-melted tar is poured into the annular area between the metal bucket and the kraft paper. After the tar cools and solidifies, the metal bucket and kraft paper are removed, and the edges of the inner and outer rings of the solidified structure are chamfered to obtain the ring-shaped polishing mold base.

8. The polishing method according to claim 6, characterized in that, The method for slotting the upper surface of the polishing mold base is as follows: First, a metal grooving tool is used to evenly open multiple longitudinal grooves and multiple transverse grooves on the upper surface of the polishing mold base. The longitudinal grooves and transverse grooves are perpendicular to each other and have the same groove shape. The spacing between adjacent grooves in the same direction is 80mm, the groove width is 5mm, and the groove depth is 10mm. Then, a multiple concentric annular fine grooves are opened on the upper surface of the polishing mold base using a metal grooving tool.

9. The polishing method according to claim 6, characterized in that, When measuring the surface profile of the test plate using a laser interferometer, the surface profile within a φ150mm diameter at the center, edge, and four corners of the test plate is measured every 12 hours. The surface profile within the measured range is better than 0.8λ, meaning the surface profile of the test plate is better than 0.8λ.

10. The polishing method according to claim 6, characterized in that, When inspecting the surface profile of the machined parts using a laser interferometer, the surface profile within a φ150mm diameter at the center, edge, and four corners of the part is measured every 12 hours. If it meets the design requirements, then the surface profile of the part meets the requirements.

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