Full bore lapping and polishing controllable annular band removal method

Abstract

Full caliber grinding and polishing controllable ring belt removal method relates to the field of full caliber polishing and grinding technology, solves the problems that the existing technology cannot accurately predict the surface removal amount distribution of the measured element, and has poor controllability, the method obtains the ring belt to be removed by detecting the actual ring belt characteristic representation of the surface of the workpiece to be polished and ground; and carries out processing simulation to obtain the simulated removal amount distribution; the simulated ring belt characteristic representation is compared with the actual ring belt characteristic representation obtained by detection, when the characteristics coincide, the speed and pressure data used in the processing simulation are used as the optimal processing parameters, and the ring belt is removed according to the optimal processing parameters. In the method, the ring belt characteristic representation is a simplified representation method of the workpiece surface, which can quantify the surface information and more intuitively reflect the surface characteristic information, and can realize the preliminary ring belt controllable removal of the full caliber polishing technology.

Description

Technical Field

[0001] This invention relates to the field of full-diameter polishing and grinding technology, and specifically to a method for controllable annular band removal in full-diameter grinding and polishing. Background Technology

[0002] Full-aperture polishing technology is often the preferred solution for high-efficiency polishing and grinding of large-aperture optical components and silicon-based materials due to its advantages such as large removal capacity and mass production capability. It can significantly improve processing efficiency while ensuring a certain level of processing quality. However, as a non-deterministic polishing method, it has problems such as complex and variable process schemes, difficulty in accurately predicting the surface removal distribution of components, and poor controllability. Furthermore, process parameters can only be manually determined, and process decisions rely on the personal experience of the processing personnel, lacking theoretical methods to guide the processing. Summary of the Invention

[0003] To address the problems of difficulty in accurately predicting the surface removal amount distribution of the component under test and poor controllability in existing technologies, this invention provides a controllable annular band removal method for full-diameter grinding and polishing. This method can efficiently simulate the distribution of removal amount in full-diameter processing and achieve controllable removal of specific annular bands.

[0004] A method for controllable annular band removal through full-diameter grinding and polishing, comprising the following steps:

[0005] Step 1: Detect the surface of the workpiece to be polished or ground to obtain the workpiece surface profile information, and convert the surface profile information into actual ring-shaped feature representation;

[0006] Step 2: Based on the actual annular feature characteristics obtained in Step 1, obtain the annular bands that need to be removed;

[0007] Step 3: Perform processing simulation on the annular band to be removed as described in Step 2 to obtain the simulated removal amount distribution;

[0008] Step 4: Simplify the simulated removal distribution obtained in Step 3 into a simulated annular feature characterization, and compare the simulated annular feature characterization with the actual annular feature characterization obtained in Step 1. If the features match, proceed to Step 5; if the features do not match, modify the process parameters during the processing simulation, return to Step 3, and continue until the features match, then proceed to Step 5.

[0009] Step 5: The speed and pressure data used in the machining simulation are then used as the optimal machining process parameters, and the workpiece is subjected to ring removal based on the optimal machining process parameters;

[0010] The beneficial effects of this invention are:

[0011] I. The method described in this invention can achieve controllable removal of the initial ring band in full-diameter polishing technology.

[0012] Second, in the method described in this invention, the ring feature characterization method is a simplified representation method of workpiece surface shape, which can quantify surface shape information and reflect surface shape feature information more intuitively.

[0013] Third, the simulation method used in the method described in this invention is a method that shifts the research target from abrasive grains to components, avoiding the modeling and analysis of machining trajectories, avoiding lengthy simulation programs, and shortening simulation time. Attached Figure Description

[0014] Figure 1 This is a flowchart of the method of the present invention;

[0015] Figure 2 This is a simulation flowchart for the processing where the ring band needs to be removed;

[0016] Figure 3 To obtain a rendering of the surface profile information of the workpiece to be tested;

[0017] Figure 4 This is a schematic diagram illustrating the characterization of the ring-shaped features of the workpiece under test.

[0018] Figure 5 A schematic diagram showing the removal of ring-shaped features from the workpiece to be tested.

[0019] Figure 6 This is a schematic diagram of a ring-type double-sided polishing device.

[0020] Figure 7 This is a schematic diagram of the instantaneous speed of the upper polishing disc;

[0021] Figure 8 This is a schematic diagram of the instantaneous velocity of the lower polishing disc;

[0022] Figure 9 To build a simulation model diagram;

[0023] Figure 10 The simulation results (self-weight pressure distribution) show the effect of polishing discs of various sizes on the pressure on the upper surface.

[0024] Figure 11 The simulation (external force pressure distribution) effect of polishing discs of various sizes on the pressure on the upper surface is shown in the figure.

[0025] Figure 12 The simulation (weight pressure distribution) effect of the polishing disks of various sizes on the pressure on the lower surface is shown in the figure.

[0026] Figure 13 The simulation (external force pressure distribution) effect of the polishing pads of various sizes on the pressure on the lower surface is shown in the figure.

[0027] Figure 14 This is a diagram showing the distribution of the amount of material to be removed from the surface.

[0028] Figure 15 This is a simulation result of the process requiring the removal of the ring band. Detailed Implementation

[0029] Combination Figures 1 to 15 This embodiment describes a method for controlling the removal of the ring band during full-diameter grinding and polishing. The method is implemented through the following steps:

[0030] Step 1: Detect the surface information of the workpiece to be tested and convert it into actual ring-shaped feature representation.

[0031] In this embodiment, the surface shape of the workpiece to be measured is regarded as extending from the center of the component to the periphery and consisting of several rings. The features of the several rings are represented in a two-dimensional coordinate system; the x-axis is the distance of the current ring from the center of the component, and the y-axis is the longitudinal height feature of the current ring. After representing the several rings from the center to the periphery in the above method, a complete ring feature characterization can be obtained, and the feature reflected is the current surface shape feature.

[0032] like Figure 3 and Figure 4 As shown, the surface profile information of the workpiece under test is obtained by detection, specifically including: the average height difference (PV value) and the component size; the heat map generated from the above surface profile information is as follows. Figure 3 As shown, it is converted into actual annular feature characterization as follows. Figure 4 As shown.

[0033] Step 2: Based on the zonal characterization results, identify the zonal bands that need to be removed;

[0034] In this embodiment, the rings to be removed are determined based on the actual ring characteristics. Rings with a height greater than the longitudinal height characteristic threshold are considered to be removed. The distance range of the rings to be removed along the x-axis in the ring characteristic representation is the ring position. The longitudinal height characteristics of the rings include, but are not limited to, the ring Ra value, the ring RMS value, and the ring PV value.

[0035] In this embodiment, the longitudinal height characteristic threshold of the ring is set to 80%, which can be adjusted up or down according to the actual surface shape. For example... Figure 5 As shown in the figure, the red part is the ring that needs to be removed.

[0036] Step 3: Perform processing simulation on the annular band to be removed to obtain the simulated removal amount distribution; such as... Figure 2 As shown, specifically:

[0037] 1) Discretize the workpiece surface into an n×n cellular mesh and discretize the continuous processing time into time steps in units of 0.1s;

[0038] 2) Construct a motion velocity distribution field based on the operating principle of the full-diameter machining equipment, and obtain the vector sum of the instantaneous motion velocity of each cell on the workpiece during equipment operation;

[0039] 3) The processing pressure distribution law is obtained through experiments, and the pressure distribution law is coupled into the constructed motion velocity distribution field.

[0040] like Figures 6 to 8 As shown, this embodiment uses a ring-type double-sided polishing equipment. The ring-type double-sided polishing process can be divided into two parts: the swing polishing of the upper polishing disc and the ring polishing of the lower polishing disc. The upper polishing disc 4 is pressed tightly against the upper surface of the optical element 6 by the workpiece clamp 5 through a pneumatic pressure system (upper polishing disc rotary motor 1, upper polishing disc radial motor 2, and cylinder 3), ensuring close contact between the upper polishing disc 4 and the optical element 6. The upper polishing disc 4 and the component disc rotate at angular velocities ω3 and ω2 respectively, simultaneously with V... p V w The optical element 6 is driven by a rotary motor 7 and a radial motor 8 of the element disk; during the processing of the upper polishing disk 4, the instantaneous velocity of any point P on the optical element 6 is the vector sum of the oscillation velocity v1 of the upper polishing disk 4, the rotational velocity v2 of the element disk, and the rotational velocity v3 of the upper polishing disk, as shown below. Figure 7 As shown in the figure, O1 is the center point of the component disk, and O2 is the center point of the upper polishing disk. The lower polishing disk 9 is driven by the lower polishing disk rotary motor 10. The processing method of the lower polishing disk 9 is the ring polishing method. When the optical element 6 is driven by the component disk to rotate and oscillate, the lower polishing disk 9 is used to polish the lower surface of the optical element 6 at a constant speed. In the ring polishing process of the lower polishing disk 9, the processing can be divided into three movements: the uniform oscillation V1 of the component disk along the radial direction of the lower polishing disk 9, the rotation ω1 of the component disk, and the rotation ω2 of the lower polishing disk, as follows. Figure 8 As shown in the figure, O1 is the center point of the component disk, O2 is the center point of the lower polishing disk, and r1 and r2 are the distances between any point P and the center points of the component disk and the lower polishing disk, respectively. The modeling method of the lower polishing disk is basically the same as that of the upper polishing disk. It is necessary to calculate the vector sum of the three component velocities caused by the three component actions at a point on the component to construct the motion velocity distribution field.

[0041] like Figure 9 As shown, in this embodiment, the pressure distribution patterns of the upper plate of the processing equipment under gravity and external forces alone are obtained through modeling and simulation. A pressure model for each cell is then constructed based on the obtained distribution patterns.

[0042] like Figures 10 to 13As shown, this embodiment models and simulates the upper polishing discs of various sizes in a pendulum-type double-sided polishing device. The dimensions of the upper discs are 300mm, 360mm, 400mm, 480mm, and 590mm. Since the upper polishing disc is circular, the external force on the upper polishing disc also originates from the center of the upper disc. Therefore, the pressure exerted on the component by the upper disc is always circumferentially symmetrical, such as... Figure 10 and Figure 11 As shown. The pressure distribution law is coupled into the constructed velocity field, as... Figure 12 and Figure 13 As shown.

[0043] 4) After obtaining the above model, as follows Figure 14 As shown, the amount of removal per unit time step for each cell is calculated based on the Preston formula. The sum of the amount of removal per cell in each time step is the total amount of removal at that cell. After calculating all n×n cells, the distribution of the amount of removal required for the entire surface can be obtained.

[0044] Step 4: After obtaining the simulated removal amount distribution, simplify it into a ring-shaped feature characterization method to obtain the result diagram of the simulation results of the ring-shaped removal process, such as... Figure 15 As shown, the longitudinal height features of each ring in the simulation result diagram of the ring to be removed, and the distance of the current ring from the center of the component, are compared with the longitudinal height features of each ring in the characteristic representation diagram of the ring to be removed obtained in step two, and the distance of the current ring from the center of the component. The longitudinal height features of the rings must not differ by more than threshold A, and the distance of the current ring from the center of the component must not differ by more than threshold B. If these conditions are met, the features are considered to match. (In this embodiment, threshold A is set to 80%, and threshold B is set to 2mm). When the features match, the above-mentioned speed, pressure, and other process information are the optimal processing technology. If the features do not match, the process parameters are modified again until they match.

[0045] Step 5: Process the workpiece according to the optimal processing technology. This allows for controllable processing of specific rings.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A controllable annular band removal method for full-diameter grinding and polishing, characterized by: A circular pendulum-type double-sided polishing device is used, the polishing device comprising an upper polishing disc and a lower polishing disc; the method is implemented by the following steps: Step 1: Detect the surface of the workpiece to be polished or ground to obtain the workpiece surface profile information, and convert the surface profile information into actual ring feature characterization results; The annular feature is characterized as follows: The surface shape of the workpiece to be measured is considered to be an extension from the center of the component to the periphery and composed of several rings. The features of these rings are represented in a two-dimensional coordinate system to form a ring feature representation. The features of the rings include the distance of the current ring from the center of the component and the longitudinal height of the current ring. The x-axis is the distance of the current ring from the center of the component, and the y-axis is the longitudinal height of the current ring. After representing the extension of several rings from the center to the periphery, a complete ring feature representation is obtained. Step 2: Based on the zonal feature characterization results obtained in Step 1, obtain the zonal bands that need to be removed; Step 3: Perform processing simulation on the annular band to be removed as described in Step 2 to obtain the simulated removal amount distribution; the specific process is as follows: Step 31: Discretize the surface of the workpiece to be tested into... The cellular grid discretizes the continuous processing time into time steps of 0.1s. Step 3.2: Construct the motion velocity distribution field to obtain the vector sum of the instantaneous motion velocity of each cell grid on the workpiece during the operation of the processing equipment; Step 33: Couple the pressure distribution law of the processing equipment into the motion velocity distribution field constructed in Step 32; The pressure distribution law of the upper polishing disk of the processing equipment under gravity and external force is obtained by modeling and simulation. The pressure distribution law is then used to construct the pressure model of each cell grid. Steps three and four: Calculate the removal amount per unit time step for each cell grid. The sum of the removal amounts for each cell grid in each time step is the total removal amount at that cell grid. After calculating all the individual cell meshes, the required amount of material to be removed is obtained for the entire surface of the workpiece under test. Step 4: Simplify the simulated removal distribution obtained in Step 3 into a simulated annular feature characterization, and compare the simulated annular feature characterization with the actual annular feature characterization obtained in Step 1. If the features match, proceed to Step 5; if the features do not match, modify the process parameters during the processing simulation, return to Step 3, and continue until the features match, then proceed to Step 5. Step 5: The speed and pressure data used in the machining simulation are then used as the optimal machining process parameters, and the workpiece is subjected to ring removal based on the optimal machining process parameters.

2. The method for controllable annular band removal by full-diameter grinding and polishing according to claim 1, characterized in that: In step two, the specific steps to obtain the rings that need to be removed are as follows: Loops that are greater than the longitudinal height feature threshold are considered as loops that need to be removed. The distance range of the x-axis corresponding to the loops that need to be removed in the loop feature representation is the position of the loop.

3. The method for controllable annular band removal through full-diameter grinding and polishing according to claim 2, characterized in that: The longitudinal height characteristics of the annulus include the annulus Ra value, the annulus RMS value, and the annulus PV value.

4. The method for controllable annular band removal by full-diameter grinding and polishing according to claim 1, characterized in that: In step four, the simulated removal distribution obtained in step three is converted into a ring-shaped feature representation in the same way as in step one, and then compared with the actual ring-shaped feature representation obtained in step one.

5. The method for controllable annular band removal by full-diameter grinding and polishing according to claim 1, characterized in that: In step four, feature matching specifically refers to comparing the simplified simulated annular feature representation obtained in step three with the actual annular feature representation obtained in step one. The difference in the longitudinal height feature of the annular band is less than or equal to threshold A, and the distance of the current annular band from the center of the element is less than or equal to threshold B.

6. The method for controllable annular band removal by full-diameter grinding and polishing according to claim 5, characterized in that: Threshold A is 80%, and threshold B is 2mm.

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