Spherical / aspheric workpiece accurate grinding and polishing machine and accurate grinding and polishing method

Abstract

The spherical center swing arc polishing machine aims at overcoming the defects that in the prior art, when a spherical center swing arc polishing machine conducts surface type correction on the precision of a polished spherical surface, the requirement for the technical level of operators is high, and an aspheric workpiece cannot be polished. According to the accurate grinding and polishing machine and the accurate grinding and polishing method for the spherical / aspheric workpiece, the surface type of the spherical workpiece can be effectively and automatically corrected, and the surface type of the aspheric workpiece can be polished and corrected. Comprising an elastic accurate grinding head / polishing die, a swing arc driving device for driving the accurate grinding head / polishing die to do swing arc motion relative to a workpiece, and a workpiece rotation driving device for supporting and mounting the machined workpiece and driving the workpiece to rotate, by the adoption of the spherical / aspheric workpiece accurate grinding and polishing machine and the accurate grinding and polishing method, accurate grinding and polishing of the spherical surface can be completed, accurate grinding and polishing of the aspheric surface can be well completed, the spherical surface and the aspheric surface with high surface type precision can be obtained, and the surface type of the aspheric surface can be obtained more easily.

Description

Technical Field

[0001] The present invention belongs to the technical field of grinding, and particularly relates to a fine grinding and polishing machine for spherical / aspherical workpieces and a fine grinding and polishing method. Background Art

[0002] When processing high-precision components such as optical parts with high surface finish and high surface shape requirements, fine grinding and polishing methods are often used to obtain surface finish. While fine grinding and polishing, the surface finish and surface shape of the parts are controlled and corrected to make the surface shape of the workpiece reach the accuracy specified by the process. In the prior art, a spherical center swing arc fine grinding and polishing machine is often used to polish spherical workpieces. The spherical center swing arc fine grinding and polishing machine includes a workpiece rotation drive device and a fine grinding head / polishing mold swing arc drive device. The fine grinding head / polishing mold is located above the workpiece. The fine grinding head / polishing mold is positioned and rotatable by a center point. The fine grinding head / polishing mold swing arc drive device drives the fine grinding head / polishing mold to swing at a constant speed. During processing, the center point holds the fine grinding head / polishing mold to fit with the surface of the workpiece. The workpiece rotation drive motor drives the workpiece to rotate. The fine grinding head / polishing mold rotates passively under the action of friction. The shape of the fine grinding head / polishing mold fits the workpiece to be polished, and the surface of the workpiece is polished. The above fine grinding head / polishing mold is in the shape of a concave spherical segment, and there is also a fine grinding head / polishing mold in the shape of a convex spherical segment for fine grinding and polishing. No matter which shape the fine grinding head / polishing mold adopts, during the forming process, the fine grinding head / polishing mold makes a uniform swing arc motion on the surface of the workpiece under the drive of the fine grinding head / polishing mold swing arc drive device. For the polishing machine with the above structure, since the workpiece is a rotating body during the forming process, the linear velocity near the center of the workpiece is lower than that at the edge position. Therefore, the allowance to be removed during polishing at the edge is greater than that at the position closer to the center. Moreover, during the forming process of the workpiece, due to various reasons, the point at a certain part is higher than the standard value, and it needs to be shaped during polishing to minimize the difference between the high point and the low point and obtain a better surface shape in order to achieve a better imaging or light-gathering effect. For the fine grinding machine or polishing machine with the above structure, since the workpiece rotation drive device drives the workpiece to rotate at a constant speed, the linear velocity decreases sequentially from the edge part of the workpiece to the center part. Therefore, the removal amount for the edge part of the workpiece during polishing is less than that for the center part, and it is difficult to perform effective surface shape control and correction. In the prior art, relying on the experience of the operator, the surface of the part with a high point and the edge of the workpiece are polished and corrected, but the operating levels of the operators vary, so the controllability of the polishing surface accuracy is low and cannot meet the requirements of precise polishing such as spherical lenses.

[0003] At present, in the market, the demand for aspherical element polishing is increasing. Using an aspherical numerical control polishing machine not only has a high input cost but also has a very slow efficiency, resulting in a very high price for current aspherical elements, restricting the wide application of aspherical elements. However, the existing spherical center swing arc precision grinding and polishing machine is of low cost and is basically available in optical enterprises. A single machine can have 4 - 6 independent workstations, which is equivalent to 6 machines. However, since the rotation speed of the workpiece is the same and the swing speed of the polishing mold is the same, and the curvature of the aspherical workpiece is variable, only the surface of the spherical workpiece can be polished, and the surface of the aspherical workpiece cannot be polished. This makes the use of the spherical center swing arc precision grinding and polishing machine single - purpose, and it cannot play its advantages of low cost and high efficiency in the forming process of aspherical workpieces, resulting in a lack of an efficient, accurate and low - cost precision grinding and polishing method for aspherical machining. Summary of the Invention

[0004] The object of the present invention is to provide a spherical / aspherical workpiece precision grinding and polishing machine and a precision grinding and polishing method that can not only effectively and automatically correct the surface shape of a spherical workpiece but also complete the surface shape polishing and correction of an aspherical workpiece, aiming at the deficiencies of the existing spherical center swing arc polishing machine, which not only requires a high technical level of operators for surface shape correction of the polished spherical surface but also cannot polish aspherical workpieces.

[0005] The technical solution for the present invention to solve the technical problems is as follows: A spherical / aspherical workpiece precision grinding and polishing machine includes an elastic precision grinding head / polishing mold, an arc swing driving device for driving the precision grinding head / polishing mold to perform an arc swing movement relative to the workpiece, a workpiece rotation driving device for supporting and installing the workpiece to be processed and driving the workpiece to rotate. The precision grinding head / polishing mold is used to be arranged opposite to the workpiece for precision grinding or polishing. It also includes a control system. The arc swing driving device includes a servo motor configured with an encoder. The encoder is electrically connected to the input end of the control system, and the servo motor is electrically connected to the output end of the control system. Under the control of the control system, the rotation speed of the servo motor when the precision grinding head / polishing mold is at the high point position is lower than the rotation speed when the precision grinding head / polishing mold is at the low point position, so that the swing speed of the precision grinding head / polishing mold at the high point position is lower than the swing speed at the low point position. A removal amount control module is set in the control system. The removal amount control module determines the rotation speed of the servo motor and the rotation speed of the workpiece according to the height position information of each point on the workpiece obtained. The workpiece rotation driving device described above includes a workpiece rotation motor and a frequency converter. The frequency converter is electrically connected to the output end of the control system. The workpiece rotation motor is electrically connected to the output end of the control system through the frequency converter. The control system controls the rotation speed of the workpiece rotation motor through the frequency converter. When the fine grinding head / polishing die is at the high point position, the rotation speed of the workpiece rotation motor is higher than that when the fine grinding head / polishing die is at the low point position, and / or when the fine grinding head / polishing die is at the small swing position, the rotation speed of the workpiece rotation motor is higher than the rotation speed of the workpiece when the fine grinding head / polishing die is at the large swing position; It further includes a pressurizing device that provides pressure to the fine grinding head / polishing die and can adjust the distance between the fine grinding head / polishing die and the workpiece. The pressurizing pressure is the same throughout the machining process. The servo motor is a servo swing motor, and the pressurizing device is a pressurizing cylinder; It further includes a rotation driving device that drives the fine grinding head / polishing die to rotate. The fine grinding head / polishing die is connected to the output end of the swing arc driving device through the rotation driving device. The rotation driving device is a pneumatic motor or an electric motor. Multiple swing arc driving devices and their encoders, multiple workpiece rotation motors and their frequency converters, and the rotation driving device of the fine grinding head / polishing die and its frequency converter are simultaneously electrically connected to the same control system, and the same control system controls the speeds of the multiple swing arc driving devices, the workpiece rotation motors, and the rotation driving device of the fine grinding head / polishing die.

[0006] A method for fine grinding and polishing spherical / aspherical workpieces uses an elastic fine grinding head / polishing die for polishing. The swing arc driving device drives the fine grinding head / polishing die to perform a swing arc movement relative to the workpiece. The workpiece rotation driving device supports and installs the workpiece to be processed and drives the workpiece to rotate, and performs fine grinding or polishing on the workpiece surface to achieve surface shape control. The position height of each point on the workpiece surface is obtained through a measuring instrument. When the fine grinding head / polishing die swings towards the high point position, the swing speed of the fine grinding head / polishing die is reduced, and the removal amount for the workpiece surface is increased, thereby correcting the surface shape, and / or when the fine grinding head / polishing die swings towards the low point position, the swing speed of the fine grinding head / polishing die is increased, and the removal amount for the workpiece surface is reduced, thereby maintaining the surface shape; When the fine grinding head / polishing die swings towards the high point position, the rotation speed of the workpiece is reduced, and the removal amount is increased. When the fine grinding head / polishing die swings towards the low point position, the rotation speed of the workpiece is increased, and the removal amount is reduced; The rotation speed of the workpiece is adjusted according to the different swing positions of the fine grinding head / polishing die. The larger the swing position of the fine grinding head / polishing die, the lower the rotation speed of the workpiece, and the removal amount is increased, and / or the smaller the swing position of the fine grinding head / polishing die, the higher the rotation speed of the workpiece, the rotation speed of the workpiece is increased, and the removal amount is reduced; When the fine grinding head / polishing die swings towards the high point position of the workpiece, increase the rotation speed of the fine grinding head / polishing die to increase the removal amount, and / or when the fine grinding head / polishing die swings towards the low point position of the workpiece, decrease the rotation speed of the fine grinding head / polishing die to reduce the removal amount; Adjust the rotation speed of the fine grinding head / polishing die according to the swing position of the fine grinding head / polishing die. The larger the swing position of the fine grinding head / polishing die, the higher the rotation speed of the fine grinding head / polishing die, to increase the removal amount, and / or the smaller the swing position of the fine grinding head / polishing die, the lower the rotation speed of the fine grinding head / polishing die, to reduce the removal amount. The advantages and beneficial effects of the present invention are: For the spherical / aspherical workpiece fine grinding and polishing machine adopting the structure of the present invention, a profilometer is used to pre-obtain the surface profile detection graph of the workpiece, so as to obtain the position information of the high points and low points on the workpiece surface. The control system controls the swing speed of the servo motor through this position information. When the fine grinding head / polishing die is at the high point position, reduce the swing speed of the fine grinding head / polishing die, so as to increase the removal amount at the high point position. When at the low point position, increase the swing speed of the fine grinding head / polishing die, so as to reduce the removal amount; Therefore, the spherical / aspherical workpiece fine grinding and polishing machine with the structure of the present invention can automatically remove and correct the height difference position of the surface profile, reduce the uncertainty of manual operation, and can obtain a forming surface with relatively high precision. It can not only process and form spherical workpieces, but is more suitable for processing and forming aspherical workpieces, can accurately control the surface profile of aspherical workpieces, realizes multi-purpose use of one machine, and can not only complete the fine grinding and polishing of spherical surfaces, but also well complete the fine grinding and polishing of aspherical surfaces.

[0007] Furthermore, a profilometer is used to pre-obtain the surface profile detection graph of the workpiece and obtain the position information of the high points and low points on the workpiece surface. The control system controls the swing speed of the servo motor and the rotation speed of the workpiece rotation drive motor through this position information, and correlates the swing amplitude of the fine grinding head / polishing die with the rotation speed of the workpiece and the swing speed of the fine grinding head / polishing die. Thus, at the high point position of the workpiece and at the position where the swing amplitude of the fine grinding head / polishing die is large, that is, at the edge position of the workpiece diameter, make the rotation speed of the workpiece faster and the swing speed of the fine grinding head / polishing die slower, so that the removal amount of the workpiece at this place increases and reaches the predetermined removal amount. After multiple measurements and corrections, a workpiece surface that coincides with the standard profile graph can be obtained.

[0008] Adopting the fine grinding and polishing method of the present invention, the height of each point on the workpiece surface is obtained by a measuring instrument, and variable-speed fine grinding or polishing is adopted. When the position of a certain point on the workpiece surface is higher than the standard value, the swinging speed of the fine grinding head / polishing die is reduced, and the removal amount of the workpiece surface is increased. Therefore, the removal amount of the height position of each point on the workpiece can be accurately controlled and removed. Therefore, spherical and aspherical surfaces with high surface accuracy can be obtained, and it is easier to obtain an aspherical surface profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 FIG. is a schematic structural diagram of an embodiment of a spherical / aspherical workpiece fine grinding and polishing machine and a fine grinding and polishing method according to the present invention; Figure 2 is Figure 1 a schematic side view; Figure 3 FIG. is a schematic structural diagram of another embodiment of a spherical / aspherical workpiece fine grinding and polishing machine and a fine grinding and polishing method according to the present invention; wherein Figure 1 on the basis of

[0010] Figure 4 FIG. is a control principle diagram of a spherical / aspherical workpiece fine grinding and polishing machine and a fine grinding and polishing method according to the present invention; Figure 5 FIG. is a schematic structural diagram of an embodiment of a spherical workpiece; Figure 6 FIG. is a schematic diagram of the shape of the central cross-section of a spherical workpiece; Figure 7 is Figure 5 a measured graph of the surface profile of the workpiece in the embodiment.

[0011] DESCRIPTION OF THE REFERENCE NUMERALS 1 - swing arc drive device; 2 - fine grinding head / polishing die connecting seat; 3 - rotation drive device; 4 - pressurizing device; 6 - workpiece shaft; 7 - workpiece rotation drive device; 71 - frequency converter; 72 - workpiece rotation motor; 8 - workpiece; 9 - fine grinding head / polishing die; 10 - workpiece clamping device; 11 - servo motor; 12 - encoder; 13 - swing arm; 14 - control system; 15 - spherical workpiece surface; 16 - curve where the central cross-section of the workpiece is located; 17 - swinging trajectory of the fine grinding head / polishing die DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] The present invention will be further described in detail below through specific embodiments. The following embodiments are only descriptive and not restrictive, and the protection scope of the present invention cannot be limited thereby.

[0013] In geometry, a spherical surface is the surface of all points at the same distance from the center of the sphere. In contrast, an "aspherical surface" refers to a surface that is not a standard spherical or ball shape and has an irregular curvature, i.e., the distances from different positions to a certain point may be different or the same.

[0014] Such as Figure 1 and Figure 2As shown in the figure, the spherical / aspherical workpiece fine grinding and polishing machine of the present invention is an improvement based on the existing spherical center swing arc fine grinding and polishing machine (also known as spherical center arc swing fine grinding and polishing machine or quasi-spherical center swing arc polishing machine). It includes an elastic fine grinding head / polishing die 9, a fine grinding head / polishing die connecting seat 2 for installing and supporting the fine grinding head / polishing die, a swing arc driving device 1 for driving the fine grinding head / polishing die to perform a swing arc movement relative to the workpiece, a pressurizing device 4 for providing pressure to the fine grinding head / polishing die so that the workpiece generates sufficient frictional force with the fine grinding head / polishing die under the action of the pressure and capable of adjusting the distance between the fine grinding head / polishing die and the workpiece, a workpiece rotation driving device 7 for supporting and fixing the workpiece to be processed and driving the workpiece to rotate, and a control system 14. The workpiece 8 is arranged opposite to the fine grinding head / polishing die 9, and the fine grinding head / polishing die is connected to the output end of the swing arc driving device 1 through the fine grinding head / polishing die connecting seat 2. The swing arc driving device 1 drives the fine grinding head / polishing die to swing along the surface of the workpiece. Under the action of the pressurizing device, when the workpiece and the fine grinding head / polishing die are pressed and in contact, the fine grinding head / polishing die can rotate driven by the workpiece when the workpiece rotates. The swing trajectory of the fine grinding head / polishing die should theoretically be consistent with the curve shape corresponding to the central cross-section of the standard surface shape of the workpiece. When it is a spherical workpiece, it is consistent with the arc shape corresponding to the central cross-section of the standard surface shape of the workpiece. The curve corresponding to the central cross-section of the standard surface shape of the workpiece rotates around the central axis to obtain the surface shape of the workpiece. In the present invention, the swing arc driving device 1 of the fine grinding head / polishing die includes a servo motor 11, which has an encoder 12. The encoder is electrically connected to the input end of the control system, and the servo motor is electrically connected to the output end of the control system. The control system obtains the swing amplitude position of the fine grinding head / polishing die by obtaining the swing amplitude position of the servo swing motor through the encoder. A removal amount control module is set in the control system. The removal amount control module controls the servo motor to increase or decrease the swing speed according to the received high point position information, low point position information, and high and low point height information of the workpiece surface. The high and low information of each point refers to the difference between the measured curvature radius and the curvature radius of the corresponding position of the standard surface shape of the workpiece. When the curvature radius of this position is greater than the curvature radius of the corresponding position of the standard surface shape of the workpiece, it is a high point, and when it is less than the curvature radius of the corresponding position of the standard surface shape of the workpiece, it is a low point. The swing speed is low at the high point position and high at the low point position, so as to adjust the amount of machining removal by adjusting the speed of the swing. In the present invention, the removal amount is adjusted by controlling the swing speed of the servo motor. The swing speed of the servo motor is lower at the position where more removal amount is required than at the position where less removal amount is required. Since the pressure of the workpiece is constant, when the swing speed of the servo motor is low, the high point position is processed for a longer time and the removal amount is more. When it is at the low point position, the processing time is less, so the removal amount is less. This working principle is not only applicable to the removal of machining allowance of spherical polishing equipment or spherical fine grinding equipment, but also applicable to the polishing and fine grinding of aspherical workpieces with different curvature radii. Such as Figure 5And 6 As shown, in the present invention, the surface profile of the workpiece is obtained through a profile testing device such as a profilometer, and the curvature radius data and / or graphics of each point on the workpiece are obtained. Through this data and graphics, the swing amplitude positions corresponding to the high point positions and low point positions on the curve 16 where the central cross-section of the workpiece is located can be obtained. Since the starting swing position of the fine grinding head / polishing die is the edge position of the workpiece, the high point positions and low point positions on the workpiece surface can be corresponding to the swing angles of the fine grinding head / polishing die. By reducing the swing speed at the corresponding position of the high point and increasing the swing speed at the low point position, the surface profile of the workpiece can be corrected. The removal amount control module of the present invention obtains the angular positions corresponding to each point of the workpiece on the central cross-section curve, and corresponds this angular position to the swing arc of the fine grinding head / polishing die to determine the swing speed of the fine grinding head / polishing die at each point, and controls the removal amount by the speed and time of the swing.

[0015] In the present invention, the workpiece rotation drive device preferably includes a workpiece rotation motor 72 and a frequency converter 71, the workpiece 8 is arranged on the workpiece shaft 6 through the workpiece clamping device 10, the frequency converter 71 is electrically connected to the output end of the control system, the frequency converter 71 is electrically connected to the workpiece rotation motor 72, the control system controls the rotation speed of the workpiece rotation motor through the frequency converter, so that the workpiece rotation motor performs variable speed movement, the rotation speed of the workpiece rotation motor is associated with the swing position of the fine grinding head / polishing mold, and changes with the change of the high and low point positions of the workpiece, when the fine grinding head / polishing mold swings to the high point position or when the fine grinding head / polishing mold swing position is at the center axis position of the workpiece, the rotation speed of the rotation motor increases, and when it is at the low point position or when the fine grinding head / polishing mold swing position is at the edge of the workpiece diameter, the rotation speed of the rotation motor decreases. Under normal circumstances, the position of the fine grinding head / polishing mold swings from the edge of the workpiece to the center of the workpiece and then swings back to the edge. In this process, the rotation speed of the workpiece rotation motor continues to increase, and continues to decrease after reaching the center position, so that the rotation linear speed of the workpiece tends to be consistent. By adopting the method of the present invention, the swing speed of the fine grinding head / polishing die is combined with the rotation speed of the workpiece for linkage control, and the surface shape of the workpiece is processed or corrected. By adjusting the rotation speed of the rotating motor, the removal amount from the center to the edge of the workpiece is adjusted as a whole, thereby avoiding the difference in removal amount caused by the difference in linear speed from the edge to the center position caused by the rotation of the workpiece, etc., thus reducing the difficulty of adjusting the swing speed of the fine grinding head and the polishing die, by adjusting the rotation speed of the workpiece to make its linear speed consistent, by adjusting the height of the local position by the swing speed, the surface shape of the workpiece surface is easier to control. The surface shape is detected multiple times and corrected multiple times, so that the surface shape reaches the designed accuracy range. The surface forming equipment and fine grinding and polishing method of the present invention are not only suitable for spherical surface forming processing, but also for non-spherical surface forming processing. The standard surface shape of the non-spherical workpiece is obtained in advance, and the swing speed of the polishing die at each high point and low point of the non-spherical workpiece and the rotation speed of the workpiece are calculated by the control system, and the forming processing can be carried out according to the predetermined standard surface shape of the workpiece. Of course, the rotation speed of the workpiece can also be comprehensively adjusted in combination with the swing amplitude and height of the swing position of the fine grinding head.

[0016] Preferably, the pressing device is a cylinder, which is used to lift the fine grinding head / polishing die and press the workpiece. Preferably, a rotation driving device for the fine grinding head / polishing die is provided. The rotation driving device for the fine grinding head / polishing die can be a motor or a pneumatic motor. The output end of the rotation driving device for the fine grinding head / polishing die is connected to the connecting seat of the fine grinding head / polishing die, and the rotation driving device for the fine grinding head / polishing die is connected to the output end of the swing arc driving device 1. With the above structure, the passive rotation of the fine grinding head / polishing die is changed to active rotation. By adjusting the rotation speed of the fine grinding head / polishing die, the removal amount of the workpiece is adjusted. When a large removal amount is required, the rotation speed of the fine grinding head / polishing die is increased; when the removal amount is small, the rotation speed of the fine grinding head / polishing die is decreased. The rotation speed of the fine grinding head / polishing die can be changed independently, or the rotation speed of the fine grinding head / polishing die and the rotation speed of the workpiece can be adjusted together. The overall principle of adjustment is that when the removal amount is large, the linear velocity difference between the rotation speed of the fine grinding head / polishing die and the rotation speed of the workpiece is increased; when the removal amount is small, the linear velocity difference between the two is decreased. By combining the two for adjustment, the adjustment range of the absolute speed is increased, and it is easier to accurately control the surface shape.

[0017] In the present invention, multiple swing arc driving devices and their encoders, multiple workpiece rotation motors and their frequency converters can be electrically connected to a control system at the same time. When a rotation driving device for the fine grinding head / polishing die is provided, multiple rotation driving devices for the fine grinding head / polishing die and their frequency converters are also electrically connected to the control system respectively. In this way, a control system can control the speeds of multiple swing arc driving devices, workpiece rotation motors, and rotation driving devices for the fine grinding head / polishing die. The workpiece forming speed and efficiency are improved.

[0018] The equipment and method of the present invention will be described in detail below in combination with the actual working process.

[0019] A profilometer is used to detect the surface shape of the processed workpiece. The workpiece structure is as Figure 5 shown, and the measured surface profile graph as shown in Figure 7 is obtained. The straight line at the height of the 0 point position is the standard surface shape graph of the workpiece. For the convenience of observing the error, the standard surface shape of the workpiece is fitted into a straight line y. The curve x that fluctuates up and down around the straight line y is the measured surface profile graph of the processed spherical workpiece or equiaxial aspherical workpiece, which is a curve x with high point positions and low point positions. Since the spherical or equiaxial aspherical is a rotating part, the measured surface profile graph x of the workpiece surface is symmetric with respect to the workpiece central axis 0-0. Half of the curve x or curve X is the swing trajectory of the polishing die on the workpiece surface, which is simply called the swing trajectory 17 of the fine grinding head / polishing die. When the polishing die is at the position with a swing angle of a, the arc angle of the measured surface profile graph of the workpiece surface is equal to a. Therefore, the swing amplitude position of the polishing die is consistent with the radian positions of each point on the curve where the workpiece is located in the central cross-section. In Figure 7In the figure, the polishing die starts to swing from the 0 position. When it reaches the 22.5 position, it reaches half of the swing range. When it reaches the 45 position, it completes one cycle of swinging and starts to swing back. Therefore, the corresponding relationship between the position of the high point and the swinging angle of the polishing die can be obtained from this curve graph. For example, when the total swinging angle a of the polishing die is equal to 45 degrees and each scale corresponds to a swinging angle of 1 degree, then from this Figure 7 figure, the swinging positions of the polishing die corresponding to each high point can be obtained as 12 degrees, 20 to 25 degrees respectively, and the angular positions corresponding to each low point are 0 - 9 degrees and 16 degrees. Therefore, the swinging speed starts to decrease at 10 degrees and decreases to the target swinging speed at 12 degrees. The swinging speed starts to decrease at 20 degrees and decreases to the target swinging speed at 25 degrees, so as to increase the removal amount at these two high points. On the contrary, the swinging speed is the highest at 0 degrees, increases to the standard speed at the 9 - degree position, starts to increase the swinging speed again from the 14 - degree position, and increases to the target swinging speed when it reaches the 16 - degree position. Since the polishing die starts to swing from the edge of the workpiece, when the polishing die just starts to swing, the rotational speed of the workpiece rotation motor is the smallest, and when it reaches the center position of the workpiece, the rotational speed of the workpiece rotation motor is the largest. In this way, the surface shape of the workpiece can be effectively corrected.

Claims

1. A spherical / aspherical workpiece fine grinding and polishing machine, comprising an elastic fine grinding head / polishing die, an arc swing driving device for driving the fine grinding head / polishing die to swing relative to the workpiece, and a workpiece rotation driving device for supporting and mounting the workpiece to be processed and driving the workpiece to rotate, the fine grinding head / polishing die is used to be arranged relative to the workpiece to perform fine grinding or polishing on the workpiece, characterized in that: It also includes a control system, wherein the arc swing drive device includes a servo motor equipped with an encoder, the encoder is electrically connected to the input end of the control system, and the servo motor is electrically connected to the output end of the control system. Under the control of the control system, when the fine grinding head / polishing mold is at a high point, the rotation speed of the servo motor is lower than the rotation speed when the fine grinding head / polishing mold is at a low point, thereby making the swing speed of the fine grinding head / polishing mold at a high point lower than the swing speed at a low point.

2. A spherical / aspherical workpiece fine grinding and polishing machine as claimed in claim 1, characterized in that: A removal amount control module is provided in the control system, and the removal amount control module determines the rotation speed of the servo motor and the rotation speed of the workpiece according to the obtained high and low position information of each point on the workpiece.

3. A spherical / aspherical workpiece fine grinding and polishing machine as claimed in claim 1 or 2, characterized in that: The workpiece rotation drive device includes a workpiece rotation motor and a frequency converter. The frequency converter is electrically connected to the output end of the control system. The workpiece rotation motor is electrically connected to the output end of the control system through the frequency converter. The control system controls the rotation speed of the workpiece rotation motor through the frequency converter. When the fine grinding head / polishing mold is at a high point, the rotation speed of the workpiece rotation motor is higher than the rotation speed of the workpiece rotation motor when the fine grinding head / polishing mold is at a low point, and / or when the fine grinding head / polishing mold is in a small swing position, the rotation speed of the workpiece rotation motor is higher than the rotation speed of the workpiece when the fine grinding head / polishing mold is in a large swing position.

4. A spherical / aspherical workpiece fine grinding and polishing machine as claimed in claim 1, characterized in that: It also includes a pressurizing device which provides pressure to the fine grinding head / polishing die and can adjust the distance between the fine grinding head / polishing die and the workpiece. The pressurizing pressure is the same during the entire processing process. The servo motor is a servo swing motor, and the pressurizing device is a pressurizing cylinder.

5. A spherical / aspherical workpiece fine grinding and polishing machine as claimed in claim 1, characterized in that: It also includes a rotating drive device for driving the fine grinding head / polishing mold to rotate, and the fine grinding head / polishing mold is connected to the output end of the swing arc drive device through the rotating drive device. The rotating drive device is a pneumatic motor or an electric motor. Multiple swing arc drive devices and their encoders, multiple workpiece rotating motors and their frequency converters, and the fine grinding head / polishing mold rotating drive device and its frequency converter are electrically connected to the same control system at the same time, and the speed of the multiple swing arc drive devices and the workpiece rotating motor and the fine grinding head / polishing mold rotating drive device is controlled by the same control system.

6. A method for fine grinding and polishing of spherical / aspherical workpieces, wherein an elastic fine grinding head / polishing die is used for polishing, an arc swing driving device drives the fine grinding head / polishing die to swing relative to the workpiece, a workpiece rotation driving device supports and installs the workpiece to be processed and drives the workpiece to rotate, and fine grinding or polishing the workpiece surface is performed to realize surface shape control, characterized in that: The height of each point on the workpiece surface is obtained by a measuring instrument. When the fine grinding head / polishing mold swings to a high point, the swing speed of the fine grinding head / polishing mold is reduced to increase the amount of removal on the workpiece surface, thereby correcting the surface shape, and / or when the fine grinding head / polishing mold swings to a low point, the swing speed of the fine grinding head / polishing mold is increased to reduce the amount of removal on the workpiece surface, thereby maintaining the surface shape.

7. A method for fine grinding and polishing of a spherical / aspherical workpiece according to claim 6, characterized in that: When the fine grinding head / polishing die swings to a high point position, the rotation speed of the workpiece is reduced and the removal amount is increased. When the fine grinding head / polishing die swings to a low point position, the rotation speed of the workpiece is increased and the removal amount is reduced.

8. A method for fine grinding and polishing of a spherical / aspherical workpiece according to claim 6, characterized in that: The rotation speed of the workpiece is adjusted as the swing position of the fine grinding head / polishing mold is different. The larger the swing position of the fine grinding head / polishing mold, the lower the rotation speed of the workpiece, increasing the removal amount, and / or the smaller the swing position of the fine grinding head / polishing mold, the higher the rotation speed of the workpiece, increasing the rotation speed of the workpiece and reducing the removal amount.

9. A method for fine grinding and polishing of a spherical / aspherical workpiece according to claim 6, characterized in that: When the fine grinding head / polishing die swings toward the high point of the workpiece, the rotation speed of the fine grinding head / polishing die is increased to increase the removal amount, and / or when the fine grinding head / polishing die swings toward the low point of the workpiece, the rotation speed of the fine grinding head / polishing die is reduced to reduce the removal amount.

10. A method for fine grinding and polishing of a spherical / aspherical workpiece according to claim 6, characterized in that: The rotation speed of the fine grinding head / polishing mold is adjusted as the swing position of the fine grinding head / polishing mold is different. The larger the swing position of the fine grinding head / polishing mold, the higher the rotation speed of the fine grinding head / polishing mold, which increases the removal amount, and / or the smaller the swing position of the fine grinding head / polishing mold, the lower the rotation speed of the fine grinding head / polishing mold, which reduces the removal amount.

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