A multi-disk processing tool and a processing method

Abstract

The present application relates to the technical fields of optical element processing, and especially relates to a multi-grinding disc processing tool and a processing method, the multi-grinding disc processing tool comprising: a mounting structure, a first motor, a speed reducer, a multi-tool clamping frame and S+1 grinding disc assemblies; the first motor is used to drive the multi-tool clamping frame to rotate around a first rotation axis through the speed reducer; the multi-tool clamping frame comprises a central fixed part, a connecting part, S clamping arms and S angle adjusters; the S+1 grinding disc assemblies comprise a central grinding disc assembly and S outer side grinding disc assemblies, the central grinding disc assembly is arranged in a central fixed hole, and the outer side grinding disc assemblies are connected with the corresponding clamping arms through the corresponding angle adjusters; the grinding disc assembly comprises a driving structure and a grinding disc, the driving structure is used to drive the grinding disc to rotate and to adjust the rotation speed and the pressure of the grinding disc. The present application is at least beneficial to reducing the design difficulty and implementation difficulty of multi-machine collaborative processing while realizing low cost and high processing efficiency.

Description

Technical Field

[0001] This invention belongs to the field of optical component processing technology, and particularly relates to a multi-grinding disc processing tool and processing method. Background Technology

[0002] In high-end equipment such as space exploration, large-aperture optical systems are a key indicator of technological level. To improve the performance of optical systems, the aperture of a single lens or the combination of multiple lenses is usually adopted to increase the size of the primary mirror, thereby significantly enhancing imaging resolution, light collection ability and photon capture efficiency. As the size and number of lenses increase, the requirements for lens processing efficiency and processing precision become more and more stringent.

[0003] Currently, most CCOS (Computer Control Optical Surface) based processing technologies use a single grinding disc for grinding and polishing. However, the efficiency of single-disc processing is low when dealing with large-diameter optical components. Although some related technologies have proposed using multi-tool collaborative processing to improve efficiency, this places stringent requirements on multi-machine collaborative control and path planning. To avoid collisions between multiple tools, complex processing trajectories usually need to be designed, which is quite difficult to implement. Summary of the Invention

[0004] In view of this, the present invention aims to provide a multi-grinding disc processing tool and processing method, which at least helps to reduce the design and implementation difficulty of multi-machine collaborative processing while achieving low cost and high processing efficiency.

[0005] To achieve the above objectives, the technical solution created by this invention is implemented as follows: This invention provides a multi-grinding disc processing tool, comprising: a mounting structure, a first motor, a reducer, a multi-tool clamping frame, and S+1 grinding disc assemblies; wherein, the first motor is mounted on the mounting structure and connected to the multi-tool clamping frame via the reducer, and the first motor drives the multi-tool clamping frame to rotate around a first rotation axis via the reducer; the multi-tool clamping frame includes a central fixing part, a connecting part, S clamping arms, and S angle adjusters, the central fixing part is connected to the reducer via the connecting part, the S clamping arms are evenly arranged circumferentially along the outer side of the central fixing part, and each clamping arm is connected to the central fixing part, the central fixing part has a central fixing hole, and the clamping arms and angle adjusters are connected to each other. Each angle adjuster is mounted on a corresponding clamping arm. The S+1 grinding disc assemblies include a central grinding disc assembly and S outer grinding disc assemblies. The central grinding disc assembly is located within a central fixing hole. The S outer grinding disc assemblies correspond one-to-one with the S clamping arms, and are connected to their respective clamping arms via corresponding angle adjusters. Each grinding disc assembly includes a drive structure and a grinding disc. The drive structure is used to rotate the grinding disc and to adjust its rotational speed and pressure. The grinding disc rotation axis of the central grinding disc assembly coincides with the first rotation axis. In the initial state, the grinding disc rotation axes of the outer grinding disc assemblies are parallel to the first rotation axis, and the distance from the grinding disc rotation axis of each outer grinding disc assembly to the first rotation axis is the same.

[0006] Furthermore, for the outer grinding disc assembly, the rotation axis of the angle adjuster is perpendicular to the corresponding grinding disc rotation axis, and the outer grinding disc assembly can rotate along the rotation axis of the corresponding angle adjuster to adjust the angle between the corresponding grinding disc rotation axis and the first rotation axis.

[0007] Furthermore, the drive structure includes a cylinder, a second motor, a pressure sensor, and a speed controller.

[0008] In another aspect, this invention provides a multi-grinding disc machining method. This method is based on the aforementioned multi-grinding disc machining tool and includes: Step 1, fixing the workpiece onto a workpiece table and acquiring surface shape error data of the workpiece; Step 2, determining the rotation axis direction of each grinding disc in the multi-grinding disc machining tool; Step 3, determining the preset translation trajectory of the multi-grinding disc machining tool. Preset translation speed and preset rotational angular velocity of the multi-tool holder Based on the preset translation trajectory Preset translation speed and preset rotation speed Step 4: Determine the machining trajectory of each grinding disc; Step 5: Obtain the theoretical dwell time of each grinding disc based on its machining trajectory, surface error data, and initial removal function; Step 6: For each grinding disc, obtain the theoretical grinding disc moving speed based on the theoretical dwell time and the distance between adjacent dwell points; For the grinding discs of the outer grinding disc assembly, obtain the theoretical grinding disc moving speed based on the preset translation speed and preset rotational angular velocity. The actual grinding disc moving speed is obtained from the distance between the center point of the grinding disc and the center point of the grinding disc in the central grinding disc assembly; for the grinding disc in the central grinding disc assembly, the actual grinding disc moving speed is obtained from the translation speed; for each grinding disc, speed matching is performed between the theoretical grinding disc moving speed and the actual grinding disc moving speed, including: obtaining the actual dwell time based on the actual grinding disc moving speed and the distance between adjacent dwell points, determining the relationship coefficient between the actual dwell time and the theoretical dwell time, obtaining a new removal function based on the initial removal function and the relationship coefficient, and determining the grinding disc rotation speed and grinding disc pressure based on the new removal function.

[0009] Furthermore, step 5 is followed by step 6, which includes: using a multi-disc machining tool to process the workpiece, and during the processing, controlling the multi-disc machining tool to follow a preset translation trajectory. The movement of the multi-grinding tool is such that its translation speed is a preset speed, and the rotational angular velocity of the multi-tool holder is also a preset speed. Each grinding disc assembly operates according to the grinding disc pressure and grinding disc speed obtained in step 5.

[0010] Furthermore, in step 3, based on the preset translation trajectory... Preset translation speed and preset rotation speed Determining the machining trajectory of each grinding disc includes: determining that the grinding disc trajectory of the central grinding disc assembly is a preset translation trajectory. ;No. The grinding wheel trajectory of each outer grinding wheel assembly satisfies: ,in, express Time of the first The x-axis and y-axis coordinates of the machining trajectory points of the outer grinding disc assembly. express Preset translation trajectory at all times The x-axis and y-axis coordinates of the trajectory points. Indicates time, Indicates the first The distance from the center point of the outer grinding disc assembly to the center point of the central grinding disc assembly. This is the serial number of the outer grinding disc assembly. The maximum value is S. For the first The distance from the center of the grinding disc in each outer grinding disc assembly to the rotation axis of the corresponding angle adjuster.

[0011] Furthermore, in step 2, determining the rotation axis direction of each grinding disc in the multi-grinding tool includes: if the surface being machined by the multi-grinding tool is a plane, then the rotation axes of each grinding disc are parallel to each other, and the rotation axes of each grinding disc are perpendicular to the surface being machined; if the surface being machined by the multi-grinding tool is a sphere, then the rotation axis direction of each grinding disc is the normal direction of the corresponding grinding point; if the surface being machined by the multi-grinding tool is an aspherical surface, then the rotation axis direction of each grinding disc is the normal direction of the corresponding grinding point on the best-fit spherical surface of the surface being machined; when the surface being machined is a sphere or an aspherical surface, if the radius of the sphere or the best-fit spherical radius of the aspherical surface is... , No. The minimum distance from the rotation axis of the angle adjuster corresponding to each outer grinding disc assembly to the first rotation axis is: Then the first The angle between the grinding wheel rotation axis of the outer grinding wheel assembly and the grinding wheel rotation axis of the central grinding wheel assembly satisfy: , This is the serial number of the outer grinding disc assembly. The maximum value is S.

[0012] Furthermore, in step 4, obtaining the theoretical dwell time of each grinding disc based on its machining trajectory, surface error data, and initial removal function includes: for each grinding disc, the number of dwell points on the grinding disc trajectory is... Surface shape error data includes Error data at discrete point n, the i-th The coordinates of the discrete points are , No. The coordinates of each station are In the The theoretical residence time at each station is: The total amount of material removed after the grinding disc has traveled its path. It satisfies Formula 1, as follows: ; Equation 1 is converted into Equation 2 in matrix-vector form, as follows: ; in, Indicates the first Material removal amount at discrete points Indicates the millstone at the 1st The unit time spent at each stop is related to the first The amount of material removed at each discrete point; Total material removal amount after all grinding discs have traversed their respective grinding disc paths It satisfies Formula 3, which is as follows: ;in, This represents the first millstone in the corresponding millstone trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the second grinding wheel on the corresponding grinding wheel trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the third grinding wheel on the corresponding grinding wheel trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the fourth millstone in the corresponding millstone trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the first millstone in the corresponding millstone trajectory. The theoretical stay time at each station; This represents the second grinding wheel on the corresponding grinding wheel trajectory. The theoretical stay time at each station; This represents the third grinding wheel on the corresponding grinding wheel trajectory. The theoretical stay time at each station; This represents the fourth millstone in the corresponding millstone trajectory. The theoretical stay time at each station; Solve Formula 3 to obtain the theoretical residence time of each grinding disc.

[0013] Furthermore, in step 5, for each grinding disc, the theoretical grinding disc moving speed is obtained based on the theoretical residence time and the distance between adjacent residence points, including: ; in, Indicates the theoretical millstone movement speed. Indicates the distance between adjacent dwelling points. Indicates the theoretical dwell time; In step 5, for the grinding disc of the outer grinding disc assembly, according to the preset translation speed and preset rotational angular velocity... The distance from the center point of the grinding disc to the center point of the central grinding disc assembly. Obtaining the actual millstone movement speed includes: ; For the grinding disc of the central grinding disc assembly, the actual grinding disc movement speed It equals the preset translation speed.

[0014] Furthermore, in step 5, based on the actual grinding disc movement speed... Spacing between adjacent stations Obtain actual length of stay include: ; Determine the actual length of stay and theoretical residence time Relationship coefficient include: The coefficient of variation is ; Based on the initial removal function and relation coefficient Get the new removal function include: .

[0015] Compared with the prior art, the present invention can achieve the following beneficial effects: The multi-grinding disc processing tool and processing method provided by the present invention can increase the number of processing tools without the need for multi-machine collaborative control, avoid the collision risk that occurs during multi-machine collaborative processing, and achieve lower processing costs and higher processing efficiency. At the same time, the processing trajectory of the multi-grinding disc processing tool can effectively suppress the tool mark effect, which is conducive to reducing the design and implementation difficulty of multi-machine collaborative processing while achieving low cost, high processing efficiency and high processing quality. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the structure of the multi-disc machining tool described in the embodiment of the present invention; Figure 2 This is a schematic diagram of the motion trajectory of each grinding disc when the multi-grinding tool is translated along a straight line according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the motion trajectory of each grinding disc when the multi-grinding tool described in the embodiment of the present invention moves along a circular trajectory.

[0017] Explanation of reference numerals in the attached drawings: 1. Mounting structure; 2. First motor; 3. Reducer; 5. Central fixing part; 4. Connecting part; 8. Clamping arm; 9. Angle adjuster; 6. Central grinding disc assembly; 7. Outer grinding disc assembly. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] refer to Figure 1This invention provides a multi-grinding disc processing tool, comprising: a mounting structure 1, a first motor 2, a reducer 3, a multi-tool clamping frame, and S+1 grinding disc assemblies, where S is an integer greater than 1; wherein, the first motor is mounted on the mounting structure 1, and the first motor is connected to the multi-tool clamping frame via the reducer 3, and the first motor is used to drive the multi-tool clamping frame to rotate around a first rotation axis via the reducer 3; the multi-tool clamping frame includes a central fixing part 5, a connecting part 4, S clamping arms 8, and S angle adjusters 9, the central fixing part 5 is connected to the reducer 3 via the connecting part 4, the S clamping arms 8 are evenly arranged circumferentially along the outer side of the central fixing part 5, and each clamping arm 8 is connected to the central fixing part 5, the central fixing part 5 has a central fixing hole, and the clamping arms 8 Each of the S+1 grinding disc assemblies corresponds to an angle adjuster 9, and each angle adjuster 9 is mounted on a corresponding clamping arm 8. The S+1 grinding disc assemblies include a central grinding disc assembly 6 and S outer grinding disc assemblies 7. The central grinding disc assembly 6 is mounted in a central fixing hole, and the S outer grinding disc assemblies 7 correspond to the S clamping arms 8. The outer grinding disc assemblies 7 are connected to the corresponding clamping arms 8 through corresponding angle adjusters 9. The grinding disc assembly includes a drive structure and a grinding disc. The drive structure is used to drive the grinding disc to rotate and to adjust the grinding disc speed and grinding disc pressure. The grinding disc rotation axis of the central grinding disc assembly 6 coincides with the first rotation axis. In the initial state, the grinding disc rotation axis of the outer grinding disc assembly 7 is parallel to the first rotation axis, and the distance from the grinding disc rotation axis of each outer grinding disc assembly 7 to the first rotation axis is the same.

[0024] In some examples, S=3, meaning that a multi-disc machining tool includes four discs.

[0025] Furthermore, for the outer grinding disc assembly 7, the rotation axis of the angle adjuster 9 is perpendicular to the corresponding grinding disc rotation axis, and the outer grinding disc assembly 7 can rotate along the rotation axis of the corresponding angle adjuster 9 to adjust the angle between the corresponding grinding disc rotation axis and the first rotation axis.

[0026] Furthermore, the drive structure includes a cylinder, a second motor, a pressure sensor, and a speed controller. In some embodiments, the second motor is connected to an angle adjuster, and the second motor, speed controller, cylinder, and grinding disc are connected in sequence. The pressure sensor is located on the pipeline that supplies air to or exhausts air from the cylinder.

[0027] The cylinder provides grinding disc pressure. In some cases, the cylinder and grinding disc can be connected by a ball joint, which ensures the flexibility of the grinding disc and allows it to fit the workpiece surface. The grinding disc pressure and height can be adjusted by the cylinder. When multiple grinding discs are working simultaneously, the height of each grinding disc can be freely adjusted, which helps the multi-grinding tool adapt to the processing of complex curved surfaces. The speed controller controls the grinding disc speed, the second motor drives the grinding disc to rotate, and the pressure sensor detects the grinding disc pressure.

[0028] In another aspect, this invention provides a multi-grinding disc machining method. This method is based on the aforementioned multi-grinding disc machining tool and includes: Step 1, fixing the workpiece onto a workpiece table and acquiring surface shape error data of the workpiece; Step 2, determining the rotation axis direction of each grinding disc in the multi-grinding disc machining tool according to the workpiece; Step 3, determining the preset translation trajectory of the multi-grinding disc machining tool. Preset translation speed and preset rotational angular velocity of the multi-tool holder Based on the preset translation trajectory Preset translation speed and preset rotation speed Step 4: Determine the machining trajectory of each grinding disc; Step 5: Obtain the theoretical dwell time of each grinding disc based on its machining trajectory, surface error data, and initial removal function; Step 6: For each grinding disc, obtain the theoretical grinding disc moving speed based on the theoretical dwell time and the distance between adjacent dwell points; For the grinding discs of the outer grinding disc assembly 7, obtain the theoretical grinding disc moving speed based on the preset translation speed and preset rotational angular velocity. The actual grinding disc moving speed is obtained by measuring the distance from the center point of the grinding disc to the center point of the grinding disc in the central grinding disc assembly 6; for the grinding disc in the central grinding disc assembly 6, the actual grinding disc moving speed is obtained based on the translation speed; for each grinding disc, speed matching is performed between the theoretical grinding disc moving speed and the actual grinding disc moving speed, including: obtaining the actual dwell time based on the actual grinding disc moving speed and the distance between adjacent dwell points, determining the relationship coefficient between the actual dwell time and the theoretical dwell time, obtaining a new removal function based on the initial removal function and the relationship coefficient, and determining the grinding disc rotation speed and grinding disc pressure based on the new removal function.

[0029] In some embodiments, step 1 further includes: calibrating the position of the workpiece and the grinding wheel, that is, establishing a workpiece coordinate system. Subsequent machining is based on the workpiece coordinate system. The position calibration also includes determining the positional relationship between the tool center points of each grinding wheel through the workpiece coordinate system, which is used for subsequent angle calculation between the grinding wheel rotation axis and the grinding wheel rotation axis of the central grinding wheel assembly 6.

[0030] In some embodiments, in step 2, the rotation axis direction of each grinding disc is the posture of each grinding disc assembly. The posture adjustment of each grinding disc assembly is as follows: the posture adjustment of the central grinding disc assembly 6 is achieved by the overall adjustment of the multi-grinding disc processing tool by the machine tool or robot, the posture adjustment of the outer grinding disc assembly 7 on the clamping arm 8 is achieved by the angle adjuster 9, and the posture of each grinding disc assembly is determined according to the surface shape of the processing surface.

[0031] Furthermore, in step 2, determining the rotation axis direction of each grinding disc in the multi-grinding tool includes: if the processing surface processed by the multi-grinding tool is a plane, then the rotation axes of each grinding disc are parallel to each other, and the rotation axis of each grinding disc is perpendicular to the processing surface. That is, in the initial state, the angle adjuster 9 works but does not adjust the angle, mainly used to keep the rotation axis direction of the grinding disc stable during the processing. The direction of the first rotation axis is controlled by the end posture of the machine tool or robot carrying the multi-grinding tool, so that the first rotation axis is perpendicular to the processing surface.

[0032] If the surface being machined by a multi-grinding tool is a spherical surface, then the rotation axis direction of each grinding wheel is the normal direction of the corresponding grinding point on the grinding wheel. If the surface being machined by a multi-grinding tool is an aspherical surface, then the rotation axis direction of each grinding wheel is the normal direction of the corresponding grinding point on the best-fit spherical surface of the machined surface. When the machined surface is a spherical or aspherical surface, if the radius of the sphere or the radius of the best-fit sphere for the aspherical surface is... , No. The minimum distance from the rotation axis of the angle adjuster 9 corresponding to the outer grinding disc assembly 7 to the first rotation axis is: Then the first The angle between the grinding wheel rotation axis of the outer grinding wheel assembly 7 and the grinding wheel rotation axis of the central grinding wheel assembly 6 satisfy: , This is the serial number of the outer grinding disc assembly. The maximum value is S. For the first The distance from the center of the grinding disc in each outer grinding disc assembly to the rotation axis of the corresponding angle adjuster.

[0033] It is understandable that, since the central grinding disc assembly 6 in the central fixing hole is located on the rotation axis of the entire device, the grinding disc trajectory of the central grinding disc assembly 6 is the same as the overall translation trajectory of the multi-grinding disc processing tool. The grinding disc on the clamping arm 8 moves with the overall translation of the multi-grinding disc processing tool, and also rotates around the first rotation axis with the rotation of the multi-grinding disc processing tool. In addition, it should be noted that during the processing, all grinding discs rotate around their own grinding disc rotation axis.

[0034] Furthermore, in step 3, based on the preset translation trajectory... Preset translation speed and preset rotation speed Determining the machining trajectory of each grinding disc includes: determining that the grinding disc trajectory of the central grinding disc assembly 6 is a preset translation trajectory. ;No. The grinding wheel trajectory of the outer grinding wheel assembly 7 satisfies: ,in, express Time of the first The x-axis and y-axis coordinates of the machining trajectory points of the outer grinding disc assembly 7. express Preset translation trajectory at all times The x-axis and y-axis coordinates of the trajectory points. Indicates time, Indicates the first The distance from the center point of the outer grinding disc assembly 7 to the center point of the central grinding disc assembly 6. , This is the serial number of the outer grinding disc assembly. The maximum value is S.

[0035] like Figure 2 As shown, when the preset translation trajectory When the path is a straight line, the grinding wheel trajectory of the central grinding wheel assembly 6 is as follows: Figure 2 The straight trajectory shown by the dashed line indicates that the grinding tracks of each outer grinding disc assembly 7 extend in a spiraling manner, using the grinding track of the central grinding disc assembly 6 as the reference. Figure 3 When the preset translation trajectory When the path is a circular line, the grinding wheel trajectory of the central grinding wheel assembly 6 is as follows: Figure 3 The circular trajectory shown by the dashed line indicates that the trajectories of each outer grinding disc assembly 7 extend in a spiral motion based on the trajectories of the central grinding disc assembly 6. Therefore, the trajectory of the entire multi-grinding tool is not a regular circular, spiral, or straight line. Rather, it exhibits a relatively chaotic yet precisely regular state compared to regular circular, spiral, or straight lines. This effectively suppresses tool mark effects and allows for accurate determination of the trajectory position without affecting the dwell time calculation, thus improving machining accuracy.

[0036] Furthermore, in step 4, obtaining the theoretical dwell time of each grinding disc based on its machining trajectory, surface error data, and initial removal function includes: for each grinding disc, the number of dwell points on the grinding disc trajectory is... Surface shape error data includes Error data at discrete point n, the i-th The coordinates of the discrete points are , No. The coordinates of each station are In the The theoretical residence time at each station is: The total amount of material removed after the grinding disc has traveled its path. It satisfies Formula 1, as follows: ; Equation 1 is converted into Equation 2 in matrix-vector form, as follows: ; in, Indicates the first Material removal amount at discrete points Indicates the millstone at the 1st The unit time spent at each stop is related to the first Material removal amount at each discrete point , ; S=3, the total material removal amount after all grinding discs have traversed their respective grinding disc paths. It satisfies Formula 3, which is as follows: ;in, This represents the first millstone in the corresponding millstone trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the second grinding wheel on the corresponding grinding wheel trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the third grinding wheel on the corresponding grinding wheel trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the fourth millstone in the corresponding millstone trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the first millstone in the corresponding millstone trajectory. The theoretical stay time at each station; This represents the second grinding wheel on the corresponding grinding wheel trajectory. The theoretical stay time at each station; This represents the third grinding wheel on the corresponding grinding wheel trajectory. The theoretical stay time at each station; This represents the fourth millstone in the corresponding millstone trajectory. The theoretical stay time at each station; Solve Formula 3 to obtain the theoretical residence time of each grinding disc.

[0037] In formula 3, The single-tool removal function matrix represents the first grinding wheel. The single-tool removal function matrix represents the second grinding disc. The single-tool removal function matrix represents the third grinding disc. The single-tool removal function matrix representing the fourth grinding disc. , , as well as All dimensions are M×N; This represents the transpose of the dwell time vector of the first millstone. This represents the transpose of the dwell time vector of the second grinding wheel. The transpose of the dwell time vector of the third grinding wheel. The transpose of the dwell time vector of the fourth millstone.

[0038] Public Notice 3 can be simplified to: ;in, Let M be the total removal function matrix of size M×4N. The total residence time matrix is ​​of size 4N×1. Thus, the removal contribution and residence time of the four grinding discs are integrated into a single total matrix equation, and the total residence time of all grinding discs can be solved by computer using the least squares method or iterative method.

[0039] Furthermore, in step 5, for each grinding disc, the theoretical grinding disc moving speed is obtained based on the theoretical residence time and the distance between adjacent residence points, including: ; in, Indicates the theoretical millstone movement speed. Indicates the distance between adjacent dwelling points. Indicates the theoretical dwell time; In step 5, for the grinding disc of the outer grinding disc assembly 7, according to the preset translation speed and preset rotational angular velocity... The distance from the center point of the grinding disc to the center point of the grinding disc assembly 6. Obtaining the actual millstone movement speed includes: ; in, This indicates the actual speed of the millstone movement. This represents the x-component of the actual grinding disc movement speed. This represents the component of the actual grinding disc movement speed along the y-axis; This indicates the x-component of the preset translational velocity. This indicates the y-component of the preset translational velocity. This indicates the rotation time of the multi-tool holder from the start of its rotation to the current moment; For the grinding disc of the central grinding disc assembly 6, the actual grinding disc movement speed It equals the preset translation speed.

[0040] Furthermore, in step 5, based on the actual grinding disc movement speed... Spacing between adjacent stations Obtain actual length of stay include: ; Determine the actual length of stay and theoretical residence time Relationship coefficient include: The coefficient of variation is ; Based on the initial removal function and relation coefficient Get the new removal function include: .

[0041] It should be noted that the amount of material removed at each residence point can be obtained based on the theoretical residence time of each grinding disc. , ,in, Represents the convolution operator. This represents the total amount of material removed by the grinding disc at the current dwell point. Represents the removal function. This represents the time the millstone stays at its current resting point.

[0042] The Preston material removal model, the theoretical basis of modern CNC optical surface forming technology, indicates that the material removal rate is linearly positively correlated with the polishing interface pressure and the relative motion speed, i.e., Equation 4 exists, as follows: ;In formula 4, Characterization processing tools in The amount removed per unit time at the location. For the comprehensive process coefficient, For the contact surface pressure, Let be the relative motion rate between the machining tool and the workpiece. The removal function in optical machining is the distribution function of the average removal amount within the interaction area between the workpiece and the machining tool per unit working time, which can be expressed as... express, The expression is as follows: , Representing processing time, the ideal processing procedure is that after the processing tool reaches the dwell point, it starts working, remains stationary for the corresponding dwell time, stops, and then moves to the next dwell point to repeat the above process. However, in reality, the distance between adjacent dwell points is generally small. This method of constantly starting and stopping the equipment will introduce a large positioning error. At the same time, the processing is discontinuous and will cause the equipment to vibrate, resulting in poor processing accuracy. Therefore, in the actual processing process, in order to ensure the continuity of processing, it is necessary to convert the theoretical dwell time into the theoretical moving speed of the processing equipment between adjacent dwell points, and then match the theoretical moving speed with the actual processing moving speed.

[0043] In step 5, the removal function is changed by adjusting the grinding disc speed or grinding disc pressure, so as to ensure the amount of material removed while achieving speed matching.

[0044] Taking a grinding disc that rotates horizontally and at a variable speed as an example, the mathematical expression for the amount of material removed by the grinding disc in one rotation cycle can be obtained as follows: ; Indicates the working area of ​​the grinding wheel machining center. Indicates the working area of ​​the grinding wheel's edge. This indicates the distance of the millstone from the center of rotation during one rotation cycle. Total amount of material removed at the site Represents the comprehensive process coefficient. Indicates processing pressure. This represents the distance from the current calculation point to the center of the millstone's rotation. Where is the radius of the grinding disc. Let be the offset of the grinding wheel's horizontal rotation; let the angular velocity of the grinding wheel's rotation be... The time it takes for the millstone to rotate one revolution is The mathematical expression for the amount of material removed by the rotating grinding disc per unit time is as follows: ;in, To measure the distance of the rotating grinding disc from the center of rotation of the grinding disc per unit time. The amount of material removed at the grinding disc; the results show the amount of material removed from the grinding disc. With rotational speed The relationship is linear, but considering the issues of grinding disc stability, polishing slurry supply changes, and thermal effects caused by variations in rotational speed during actual processing, the actual material removal rate of the grinding disc is... With rotational speed The relationship is non-linear. Therefore, before formal processing, a variable speed experiment can be conducted using the same processing material to plot the relationship curve between the grinding disc removal function and the rotational speed, which can be used to verify the accuracy of the grinding disc rotational speed.

[0045] The rotation of the grinding disc is driven by a second motor. Modern motor speed control technology is mature and easy to achieve high-precision real-time control. Taking variable speed machining as an example, the theoretical dwell time is... The total number of revolutions of the millstone corresponding to the dwell point is To achieve the corresponding material removal rate, the theoretical initial rotational speed of the grinding disc is: The total number of revolutions of the grinding disc remains unchanged, according to the relationship coefficient The final grinding disc speed obtained by solving the problem The details are as follows: ; .

[0046] Furthermore, step 5 is followed by step 6, which includes: using a multi-disc machining tool to process the workpiece, and during the processing, controlling the multi-disc machining tool to follow a preset translation trajectory. The movement of the multi-grinding tool is such that its translation speed is a preset speed, and the rotational angular velocity of the multi-tool holder is also a preset speed. Each grinding disc assembly operates according to the grinding disc pressure and grinding disc speed obtained in step 5.

[0047] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0048] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A multi-grinding disc machining tool, characterized in that, include: The installation structure includes a first motor, a reducer, a multi-tool holder, and S+1 grinding disc assemblies, where S is an integer greater than 1. The first motor is mounted on the mounting structure and is connected to the multi-tool clamping frame via a reducer. The first motor is used to drive the multi-tool clamping frame to rotate around the first rotating axis via the reducer. The multi-tool holder includes a central fixing part, a connecting part, S clamping arms, and S angle adjusters. The central fixing part is connected to the reducer through the connecting part. The S clamping arms are evenly arranged circumferentially along the outer side of the central fixing part, and each clamping arm is connected to the central fixing part. The central fixing part has a central fixing hole. The clamping arms and angle adjusters correspond one-to-one, and each angle adjuster is set on the corresponding clamping arm. S+1 grinding disc assemblies include a central grinding disc assembly and S outer grinding disc assemblies. The central grinding disc assembly is set in the central fixing hole. The S outer grinding disc assemblies correspond one-to-one with the S clamping arms. The outer grinding disc assemblies are connected to the corresponding clamping arms through corresponding angle adjusters. The grinding wheel assembly includes a drive structure and a grinding wheel. The drive structure is used to drive the grinding wheel to rotate and to adjust the grinding wheel speed and grinding wheel pressure. The grinding wheel rotation axis of the central grinding wheel assembly coincides with the first rotation axis. In the initial state, the grinding wheel rotation axis of the outer grinding wheel assembly is parallel to the first rotation axis, and the distance from the grinding wheel rotation axis of each outer grinding wheel assembly to the first rotation axis is the same.

2. The multi-disc machining tool according to claim 1, characterized in that, For the outer grinding disc assembly, the rotation axis of the angle adjuster is perpendicular to the corresponding grinding disc rotation axis. The outer grinding disc assembly can rotate along the rotation axis of the corresponding angle adjuster to adjust the angle between the corresponding grinding disc rotation axis and the first rotation axis.

3. The multi-disc machining tool according to claim 1, characterized in that, The drive structure includes a cylinder, a second motor, a pressure sensor, and a speed controller; S=3。 4. A multi-grinding disc processing method, characterized in that, The multi-grinding disc machining method is implemented based on the multi-grinding disc machining tool according to any one of claims 1 to 3, and the multi-grinding disc machining method includes: Step 1: Fix the workpiece onto the workpiece stage and obtain the workpiece surface shape error data; Step 2: Determine the rotation axis direction of each grinding disc in the multi-grinding tool according to the workpiece; Step 3: Determine the preset translation trajectory of the multi-disc machining tool. Preset translation speed and preset rotational angular velocity of the multi-tool holder Based on the preset translation trajectory Preset translation speed and preset rotation speed Determine the machining trajectory of each grinding disc; Step 4: Obtain the theoretical dwell time of each grinding disc based on the surface error data, the machining trajectory of each grinding disc, and the initial removal function of each grinding disc. Step 5: For each grinding disc, obtain the theoretical grinding disc moving speed based on the theoretical dwell time and the distance between adjacent dwell points; For the grinding disc of the outer grinding disc assembly, based on the preset translation speed and preset rotational angular velocity... The actual grinding disc movement speed is obtained by measuring the distance from the center point of the grinding disc to the center point of the central grinding disc assembly. For the grinding disc of the central grinding disc assembly, the actual grinding disc movement speed is obtained based on the translation speed; For each grinding disc, speed matching is performed between the theoretical grinding disc moving speed and the actual grinding disc moving speed, including: obtaining the actual dwell time based on the actual grinding disc moving speed and the distance between adjacent dwell points, determining the relationship coefficient between the actual dwell time and the theoretical dwell time, obtaining a new removal function based on the initial removal function and the relationship coefficient, and determining the grinding disc rotation speed and grinding disc pressure based on the new removal function.

5. The multi-grinding disc processing method according to claim 4, characterized in that, Step 5 is followed by step 6, which includes: using a multi-disc machining tool to process the workpiece, and during the processing, controlling the multi-disc machining tool to follow a preset translation trajectory. The movement of the multi-grinding tool is such that its translation speed is a preset speed, and the rotational angular velocity of the multi-tool holder is also a preset speed. Each grinding disc assembly operates according to the grinding disc pressure and grinding disc speed obtained in step 5.

6. The multi-disc processing method according to claim 4, characterized in that, In step 3, based on the preset translation trajectory Preset translation speed and preset rotation speed Determining the machining trajectory of each grinding disc includes: determining that the grinding disc trajectory of the central grinding disc assembly is a preset translation trajectory. ;No. The grinding wheel trajectory of each outer grinding wheel assembly satisfies: ,in, express Time of the first The x-axis and y-axis coordinates of the machining trajectory points of the outer grinding disc assembly. express Preset translation trajectory at all times The x-axis and y-axis coordinates of the trajectory points. Indicates time, Indicates the first The distance from the center point of the outer grinding disc assembly to the center point of the central grinding disc assembly. This is the serial number of the outer grinding disc assembly. The maximum value is S.

7. The multi-grinding disc processing method according to claim 4, characterized in that, In step 2, determining the rotation axis direction of each grinding disc in the multi-grinding tool includes: if the surface being machined by the multi-grinding tool is a plane, then the rotation axes of each grinding disc are parallel to each other and perpendicular to the surface being machined; if the surface being machined by the multi-grinding tool is a sphere, then the rotation axis direction of each grinding disc is the normal direction of the corresponding grinding point; if the surface being machined by the multi-grinding tool is an aspherical surface, then the rotation axis direction of each grinding disc is the normal direction of the corresponding grinding point on the best-fit sphere of the surface being machined. When the machined surface is a spherical or aspherical surface, if the best-fit spherical radius or the radius of the aspherical surface is... , No. The minimum distance from the rotation axis of the angle adjuster corresponding to each outer grinding disc assembly to the first rotation axis is: Then the first The angle between the grinding wheel rotation axis of the outer grinding wheel assembly and the grinding wheel rotation axis of the central grinding wheel assembly satisfy: , This is the serial number of the outer grinding disc assembly. The maximum value is S. For the first The distance from the center of the grinding disc in each outer grinding disc assembly to the rotation axis of the corresponding angle adjuster.

8. The multi-grinding disc processing method according to claim 6, characterized in that, In step 4, the theoretical dwell time of each grinding disc is obtained based on its machining trajectory, surface error data, and initial removal function. For each grinding disc, the number of dwell points on the grinding disc trajectory is: Surface shape error data includes Error data at discrete point n, the i-th The coordinates of the discrete points are , No. The coordinates of each station are In the The theoretical residence time at each station is: The total amount of material removed after a grinding disc has traveled along its corresponding grinding disc path. It satisfies Formula 1, which is as follows: ； Equation 1 is converted into Equation 2 in matrix-vector form, as follows: ; in, Indicates the first Material removal amount at discrete points Indicates the millstone at the 1st The unit time spent at each stop is related to the first Material removal amount at each discrete point , ; When S=3, the total material removal amount after all grinding discs have traversed their respective grinding disc paths. It satisfies Formula 3, which is as follows: ;in, This represents the first millstone in the corresponding millstone trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the second grinding wheel on the corresponding grinding wheel trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the third grinding wheel on the corresponding grinding wheel trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the fourth millstone in the corresponding millstone trajectory. The unit time spent at each stop is related to the first The amount of material removed at each discrete point; This represents the first millstone in the corresponding millstone trajectory. The theoretical stay time at each station; This represents the second grinding wheel on the corresponding grinding wheel trajectory. The theoretical stay time at each station; This represents the third grinding wheel on the corresponding grinding wheel trajectory. Theoretical stay time at each station; This represents the fourth millstone in the corresponding millstone trajectory. Theoretical stay time at each station; Solve Formula 3 to obtain the theoretical residence time of each grinding disc.

9. The multi-disc machining method according to claim 8, characterized in that, In step 5, for each grinding disc, the theoretical grinding disc moving speed is obtained based on the theoretical residence time and the distance between adjacent residence points, including: ； in, Indicates the theoretical millstone movement speed. Indicates the distance between adjacent dwelling points. Indicates the theoretical dwell time; In step 5, for the grinding disc of the outer grinding disc assembly, according to the preset translation speed and preset rotational angular velocity... The distance from the center point of the grinding disc to the center point of the central grinding disc assembly. Obtaining the actual millstone movement speed includes: ； in, This indicates the actual speed of the millstone movement. This represents the x-component of the actual grinding disc movement speed. This represents the component of the actual grinding disc movement speed along the y-axis; This indicates the x-component of the preset translational velocity. This indicates the y-component of the preset translational velocity. This indicates the rotation time of the multi-tool holder from the start of its rotation to the current moment; For the grinding disc of the central grinding disc assembly, the actual grinding disc movement speed It equals the preset translation speed.

10. The multi-disc processing method according to claim 9, characterized in that, In step 5, based on the actual grinding disc movement speed... Spacing between adjacent stations Obtain actual length of stay include: ; Determine the actual length of stay and theoretical residence time Relationship coefficient include: The coefficient of variation is ; Based on the initial removal function and relation coefficient Get the new removal function include: .

Images