Ultra-precision small-bore optical grinding machine with integrated polishing function and machining process thereof

Abstract

This invention relates to the field of ultra-precision optical grinding machines, providing an ultra-precision small-diameter optical grinding machine with integrated polishing function and its processing technology. The small-diameter optical grinding machine achieves micron-level feed and single-point grinding through multi-axis coordinated motion. Simultaneously, the positional distribution of the machine tool's grinding wheel axis, high-speed grinding spindle, and B-axis hydrostatic rotary table makes it easier for the torque of the B-axis hydrostatic rotary table to meet the cutting torque generated by the grinding force, improving the surface accuracy and stability of optical parts. This solves the problems of fragility and inefficient polishing processes for strongly interfering geometric components and thin-walled fragile parts during rough grinding. The workpiece hydrostatic spindle holds the bar stock through a fixture with an internal cavity. After processing, the workpiece can be cut off, and the remaining length of the bar stock can be extracted from the fixture to process the next workpiece. This solves the current problem of ultra-precision machine tools being unable to achieve small-batch processing with optical component bar stock in a single clamping, improving processing accuracy and efficiency.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision optical grinding machines, and more particularly to an ultra-precision small-diameter optical grinding machine with integrated polishing function and its processing technology. Background Technology

[0002] In the field of ultra-precision machining of brittle materials and complex parts with strong geometric interference, current production mainly relies on imported general-purpose five-axis machining centers. However, when faced with demanding machining tasks such as high-precision optical components, the inherent limitations of such general-purpose equipment become increasingly apparent. First, their motion control precision and system rigidity often fail to meet micron or even nanometer-level machining tolerances, resulting in the final product's machining accuracy and surface quality falling short of ideal standards. Second, when machining hard and brittle materials such as quartz glass, traditional machining methods easily introduce subsurface damage such as microcracks beneath the surface of the parts, which severely affects the optical performance and long-term reliability of the components. Furthermore, this equipment suffers from low processing efficiency, making it difficult to meet the needs of small-batch, high-efficiency production models, thus hindering the development of related high-end manufacturing fields. Summary of the Invention

[0003] This invention provides an ultra-precision small-diameter optical grinding machine with integrated polishing function to solve the problems of low processing efficiency and fragile workpieces during processing in the prior art.

[0004] This invention provides an ultra-precision small-diameter optical grinding machine with integrated polishing function, comprising:

[0005] Machine tool body;

[0006] The main support frame assembly includes a main support frame body and multiple air passive vibration isolators. The multiple air passive vibration isolators are vertically and spaced apart on the upper part of the main support frame body, and the upper ends of the multiple air passive vibration isolators are connected to the machine tool body.

[0007] X-axis hydrostatic guide rail hydrostatic unit, the X-axis hydrostatic guide rail hydrostatic unit is arranged along the X-axis on the upper part of the machine tool body;

[0008] Z-axis hydrostatic guide rail hydrostatic unit, the Z-axis hydrostatic guide rail hydrostatic unit is arranged along the Z-axis on the upper part of the machine tool body;

[0009] The B-axis hydrostatic rotary table is located above the Z-axis hydrostatic guide rail hydrostatic unit. A high-speed grinding spindle is located on the upper part of the B-axis hydrostatic rotary table. The B-axis hydrostatic rotary table is used to drive the high-speed grinding spindle to rotate around the B-axis. The high-speed grinding spindle is used to mount the grinding wheel and drive the grinding wheel to rotate around the C-axis.

[0010] The X and Z axes maintain a stable oil temperature in the internal return oil groove to ensure the stability of the guide rail hydrostatic system's accuracy and the repeatability of the X and Z axes, thereby guaranteeing the consistency of the machined dimensions and surface accuracy. The B-axis hydrostatic rotary table and the X and Z axes are designed with hydraulic oil of the same kinematic viscosity and pressure, and the oil temperature ensures the stability of the B-axis center height and rotation center coordinates.

[0011] A vertical drive unit is disposed on the upper part of the X-axis hydrostatic guide rail hydrostatic unit;

[0012] The workpiece hydrostatic spindle is located on one side of the vertical drive unit and above the B-axis hydrostatic rotary table. The workpiece hydrostatic spindle is equipped with a clamp, which is hollow inside and used for manual extraction of the bar stock. The clamp holds the bar stock, enabling the processing of multiple workpieces from a single bar stock. The vertical drive unit drives the workpiece hydrostatic spindle to move along the Y-axis. An acoustic emission sensor is installed on the workpiece hydrostatic spindle to detect the AE signal of the grinding wheel, enabling rapid tool setting and collision prevention on the machine tool.

[0013] An ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention further includes:

[0014] Electrical control cabinet;

[0015] An external support is provided, which surrounds the outer periphery of the main support frame assembly. An opening is provided on the upper part of the external support, through which the machine tool body extends. The electrical control cabinet is located on the upper part of the external support.

[0016] According to the present invention, an ultra-precision small-diameter optical grinding machine with integrated polishing function is provided, wherein a grinding fine-tuning mechanism is provided on the upper part of the B-axis hydrostatic rotary table, and the high-speed grinding spindle is provided on the upper part of the grinding fine-tuning mechanism.

[0017] According to the present invention, an ultra-precision small-diameter optical grinding machine with integrated polishing function is provided. The machine tool body is provided with two water return holes, which are symmetrically arranged and located on both sides of the Z-axis hydrostatic guide rail hydrostatic unit near the X-axis hydrostatic guide rail hydrostatic unit.

[0018] According to the present invention, an ultra-precision small-diameter optical grinding machine with integrated polishing function is provided, wherein an acoustic emission sensor is provided on the workpiece hydrostatic spindle, and the acoustic emission sensor is used to detect the AE signal of the grinding wheel.

[0019] According to the present invention, an ultra-precision small-diameter optical grinding machine with integrated polishing function is provided, wherein the high-speed grinding spindle is provided with a grinding wheel axis, and the coordinate point of the grinding wheel clamping the grinding wheel is located at the intersection of the axis of the high-speed grinding spindle and the axis of the B-axis hydrostatic rotary table.

[0020] The present invention also provides a processing technology for an ultra-precision small-diameter optical grinding machine with integrated polishing function, the processing technology being based on the ultra-precision small-diameter optical grinding machine with integrated polishing function described in any one of the above claims, comprising:

[0021] For rough grinding and shaping, firstly, a disc grinding wheel is used to roughen the inner spherical outer cantilever column, and then the disc grinding wheel is used to remove excess material beyond the outer diameter reference. Next, an inner contour grinding wheel for roughing is used to roughen the inner spherical surface. During this process, the B-axis hydrostatic turntable needs to be rotated to a fixed angle, thereby causing the grinding wheel rotation axis to form a fixed angle with the workpiece axis. The fixed angle is determined by calculating the workpiece dimensions. During the roughing of the inner spherical surface, the X-axis and Y-axis positions are fixed, and only the Z-axis needs to be fed. After the inner spherical surface is roughened, the disc grinding wheel is used to roughen the outer spherical outer cantilever column. Then, the B-axis hydrostatic turntable rotates so that the angle between the grinding wheel axis and the workpiece axis is 90°. After the Z-axis feed drives the roughing outer contour grinding wheel to a certain position, the roughing of the outer spherical surface can be achieved by feeding only the X-axis. At this point, the hemispherical harmonic oscillator workpiece is initially formed.

[0022] Semi-finish grinding is performed using the inner spherical surface and inner cylindrical surface of the inner contour grinding wheel for semi-finishing; the outer spherical surface is semi-finished using the outer contour grinding wheel for semi-finishing. The rotation angle of the B-axis hydrostatic turntable during semi-finishing of the inner and outer spherical surfaces is the same as the rotation angle of the B-axis hydrostatic turntable during roughing of the inner and outer spherical surfaces. The outer cylindrical surface is then semi-finished using the disc grinding wheel.

[0023] Fine grinding is performed by using an inner contour grinding wheel for fine grinding to grind the inner spherical surface and the inner cylindrical surface, and by using an outer contour grinding wheel for fine grinding to grind the outer spherical surface. The rotation angle of the B-axis hydrostatic turntable during fine grinding of the inner and outer spherical surfaces is the same as the rotation angle of the B-axis hydrostatic turntable during rough grinding of the inner and outer spherical surfaces. Then, the outer cylindrical surface is finely ground using the disc grinding wheel.

[0024] In each of the above processing steps, the grinding axis and the workpiece rotate around their own axes respectively;

[0025] The outer spherical column is cut off using a cutting grinding wheel to obtain the finished product;

[0026] After opening the clamp and pulling the bar out to a predetermined length, the bar is then clamped back in place using the clamp.

[0027] Repeat the above steps until the bar stock is processed.

[0028] According to the processing technology of an ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention, in the steps of semi-fine grinding and fine grinding, the end faces of the inner contour grinding wheel and the outer contour grinding wheel are obliquely cut to the surface to be processed at a fixed angle α, and the axis of the inner contour grinding wheel or the outer contour grinding wheel intersects the axis of the workpiece at the center of the workpiece sphere.

[0029] The ultra-precision small-diameter optical grinding machine with integrated polishing function provided by this invention achieves micron-level feed and single-point grinding through multi-axis coordinated motion. Simultaneously, the positional distribution of the machine tool's grinding wheel axis, grinding axis, and rotary table axis makes it easier for the torque of the B-axis hydrostatic rotary table to meet the cutting torque generated by the grinding force, improving the surface accuracy and stability of optical parts. This solves the problems of fragility in rough grinding and inefficient polishing processes for highly interfering geometric components and thin-walled fragile parts. The workpiece hydrostatic spindle holds the bar stock through an internally hollow fixture. After processing, the workpiece can be cut off, and the remaining length of the bar stock can be extracted from the fixture to process the next workpiece. This solves the current problem of ultra-precision machine tools being unable to achieve small-batch processing with optical component bar stock in a single clamping, thus improving processing efficiency. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is one of the three-dimensional structural schematic diagrams of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0032] Figure 2 This is the second three-dimensional structural schematic diagram of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0033] Figure 3 This is the third three-dimensional structural schematic diagram of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0034] Figure 4 This is a top view schematic diagram of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0035] Figure 5 This is a top view of the main body of the machine tool with integrated polishing function provided by the present invention.

[0036] Figure 6 This is one of the schematic diagrams of the processing technology of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0037] Figure 7 This is one of the schematic diagrams of the processing technology of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0038] Figure 8 This is one of the schematic diagrams of the processing technology of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0039] Figure 9 This is one of the schematic diagrams of the processing technology of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by the present invention.

[0040] Figure label:

[0041] 10. Machine tool body; 11. Water return hole; 12. Oil return groove; 20. X-axis hydrostatic guide rail hydrostatic unit; 30. Z-axis hydrostatic guide rail hydrostatic unit; 40. B-axis hydrostatic rotary table; 41. Grinding fine adjustment mechanism; 50. High-speed grinding spindle; 60. Vertical drive unit; 61. Vertical Y-axis; 62. Mounting bracket; 70. Workpiece hydrostatic spindle; 71. Fixture; 80. External support; 81. Control cabinet; 90. Main support frame body; 91. Air passive vibration isolator. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present 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. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0045] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] like Figure 1 and Figure 2 As shown, the ultra-precision small-diameter optical grinding machine with integrated polishing function includes a machine body 10, a main support frame assembly, an X-axis hydrostatic guide rail hydrostatic unit 20, a Z-axis hydrostatic guide rail hydrostatic unit 30, a B-axis hydrostatic rotary table 40, a vertical drive unit 60, and a workpiece hydrostatic spindle 70. The main support frame assembly includes a main support frame body 90 and multiple air passive vibration isolators 91. The multiple air passive vibration isolators 91 are vertically and spaced apart on the upper part of the main support frame body 90, and the upper ends of the multiple air passive vibration isolators 91 are connected to the machine body 10.

[0048] The X-axis hydrostatic guideway hydrostatic unit 20 is disposed on the upper part of the machine tool body 10 along the X-axis; the Z-axis hydrostatic guideway hydrostatic unit 30 is disposed on the upper part of the machine tool body 10 along the Z-axis; both the X-axis hydrostatic guideway hydrostatic unit 20 and the Z-axis hydrostatic guideway hydrostatic unit 30 adopt hydrostatic guideways, which can provide high-precision, high-rigidity and low-friction motion support, ensuring the smoothness and accuracy of the X-axis and Z-axis movements, thereby improving the overall machining accuracy.

[0049] The B-axis hydrostatic rotary table 40 is mounted on top of the Z-axis hydrostatic guide rail hydrostatic unit 30. The Z-axis hydrostatic guide rail hydrostatic unit 30 drives the B-axis hydrostatic rotary table 40 to reciprocate along the Z-axis. A high-speed grinding spindle 50 is mounted on top of the B-axis hydrostatic rotary table 40. The B-axis hydrostatic rotary table 40 drives the high-speed grinding spindle 50 to rotate around the B-axis. The high-speed grinding spindle 50 mounts the grinding wheel and drives the grinding wheel to rotate around the C-axis. The B-axis hydrostatic rotary table 40 can achieve precise angular positioning and rotation. Combined with the high-speed grinding spindle 50, it can perform grinding operations on complex curved surfaces and profiles.

[0050] The vertical drive unit 60 is located above the X-axis hydrostatic guide rail hydrostatic unit 20, which drives the vertical drive unit 60 to reciprocate along the Y-axis. The workpiece hydrostatic spindle 70 is located on one side of the vertical drive unit 60 and is positioned above the B-axis hydrostatic turntable 40. The workpiece hydrostatic spindle 70 is equipped with a clamp 71, which is hollow inside and used to manually extract the bar stock. The clamp 71 holds the bar stock, enabling the processing of multiple workpieces from a single bar stock. The vertical drive unit 60 drives the workpiece hydrostatic spindle 70 to move along the Y-axis. An acoustic emission sensor is installed on the workpiece hydrostatic spindle 70 to detect the AE signal of the grinding wheel, enabling rapid tool setting and collision prevention of the machine tool.

[0051] The ultra-precision small-diameter optical grinding machine with integrated polishing function provided by this invention is a five-axis, four-linkage ultra-precision CNC small-diameter optical grinding machine with multiple processing capabilities including rough grinding, fine grinding, and polishing. The workpiece hydrostatic spindle 70, high-speed grinding spindle 50, B-axis hydrostatic rotary table 40, X-axis hydrostatic guide rail hydrostatic unit 20, and Z-axis hydrostatic guide rail hydrostatic unit 30 all adopt a combination of direct drive technology and hydrostatic technology. Micron-level feed and single-point grinding are achieved through multi-axis coordinated motion. At the same time, the positional distribution of the machine tool grinding wheel axis, high-speed grinding spindle 50, and B-axis hydrostatic rotary table 40 makes it easier for the torque of the B-axis hydrostatic rotary table 40 to meet the cutting torque formed by the grinding force, thereby improving the surface accuracy and stability of optical parts and solving the problems of fragility of strong interference geometric components and thin-walled fragile parts in the rough grinding process and inefficiency in the polishing process. The workpiece hydrostatic spindle 70 clamps the bar stock through a fixture 71 with an internal cavity. After processing, the workpiece can be cut off and the remaining length of the bar stock can be extracted from the fixture 71 to process the next workpiece. This solves the problem that current ultra-precision machine tools cannot achieve small-batch processing with optical element bars in a single clamping, thus improving processing efficiency.

[0052] In one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the vertical drive unit 60 includes a mounting bracket 62 and a vertical Y-axis 61. The mounting bracket 62 is located on the upper part of the X-axis hydrostatic guide rail hydrostatic unit 20. The vertical Y-axis 61 is located on one side of the mounting bracket 62 and is vertically positioned. The slide of the vertical Y-axis 61 is connected to the workpiece hydrostatic spindle 70, and the vertical Y-axis 61 is used to drive the workpiece hydrostatic spindle 70 to move along the Y-axis. The vertical Y-axis 61 allows the workpiece hydrostatic spindle 70 to move precisely in the Y-axis direction, achieving precise positioning and feeding of the workpiece, meeting the requirements of ultra-precision machining. The mounting bracket 62 provides stable support for the vertical Y-axis 61, ensuring the rigidity and stability of the entire vertical drive unit 60.

[0053] In one embodiment of the present invention, such as Figure 5 As shown, the upper part of the machine tool body 10 is provided with an oil return groove 12. The X and Z axes maintain the stability of the oil temperature in the internal oil return groove 12 to ensure the stability of the guide rail hydrostatic system and the repeatability of the X and Z axes, so as to ensure the consistency of the machining dimensions and surface accuracy. The B-axis hydrostatic rotary table and the X and Z axes are designed with hydraulic oil of the same kinematic viscosity and pressure. The oil temperature ensures the stability of the B-axis center height and rotation center coordinates.

[0054] In one embodiment of the present invention, such as Figure 3As shown, the ultra-precision small-diameter optical grinding machine with integrated polishing function also includes an electrical control cabinet, a main support frame assembly, and an external support 80. The machine body 10 is located on top of the main support frame assembly. The external support 80 surrounds the outer perimeter of the main support frame assembly, and an opening is provided at the top of the external support 80 through which the machine body 10 extends. The main support frame assembly and the external support 80 form an inner and outer double support frame, and the machine body 10 is connected to the main support frame assembly. The electrical control cabinet is located on top of the external support 80. Preferably, one side of the external support 80 has a downwardly recessed portion, and the electrical control cabinet is located within the recess. The electrical control cabinet is connected to the external support 80 by bolts. Placing the electrical control cabinet within the recess effectively utilizes the space on one side of the external support 80 and lowers the installation height of the electrical control cabinet, thereby lowering the overall center of gravity of the small-diameter optical grinding machine and improving its stability. The main support frame assembly and the external support 80 are connected to form an integrated structure, enabling the entire machine to be hoisted as a whole, improving transportation efficiency.

[0055] In one embodiment of the present invention, such as Figure 3 As shown, four air passive vibration isolators 91 are provided in this embodiment. However, the number of air passive vibration isolators 91 is not limited to this and is determined based on factors such as the shape of the main support frame body 90 and the weight of the machine tool body 10. The main support frame body 90 is welded from square tubing. The four air passive vibration isolators 91 are vertically and spaced apart on the upper part of the main support frame body 90. The lower ends of the four air passive vibration isolators 91 are bolted to the main support frame body 90, and the upper ends are bolted to the machine tool body 10. The air passive vibration isolators 91 provide a stable support platform for the machine tool body 10. They effectively isolate external vibrations of 5Hz and above, significantly reducing the impact of low-frequency environmental vibrations on the machining process, thereby significantly improving the stability of the moving parts on the machine bed. This is crucial for the machining accuracy of ultra-precision small-diameter optical grinding machines, especially during high-precision machining operations such as micron-level feed and single-point grinding, ensuring the stability and consistency of machining accuracy. Furthermore, the use of the air passive vibration isolator 91 enhances the overall vibration resistance and damping characteristics of the machine tool. During the operation of the machine tool, whether it is a vibration source from inside the machine tool, such as the rotation of the high-speed grinding spindle 50 and the grinding force of the grinding wheel, or vibration interference from the external environment, the air passive vibration isolator 91 can effectively absorb and attenuate these vibrations, thereby reducing the negative impact of vibration on machining accuracy. This not only improves the surface quality and dimensional accuracy of the machined parts, but also extends the service life of key machine tool components and reduces the maintenance cost and repair frequency of the machine tool.

[0056] In one embodiment of the present invention, such as Figure 2As shown, a grinding fine-tuning mechanism 41 is provided on the upper part of the B-axis hydrostatic rotary table 40, and a high-speed grinding spindle 50 is located on the upper part of the grinding fine-tuning mechanism 41. The grinding fine-tuning mechanism 41 is used to adjust the height of the high-speed grinding spindle 50. The grinding fine-tuning mechanism 41 has the following two effects: Firstly, it allows the operator to flexibly adjust the height of the high-speed grinding spindle 50 according to different processing requirements and workpiece sizes. This is crucial for processing workpieces of different specifications, especially when processing small-diameter optical components, ensuring the optimal contact position between the grinding wheel and the workpiece, thereby improving processing efficiency and quality. Secondly, through the grinding fine-tuning mechanism 41, the operator can precisely control the height of the high-speed grinding spindle 50 to adapt to different processing requirements. For example, in different processing stages such as rough grinding, semi-finish grinding, and finish grinding, the contact position between the grinding wheel and the workpiece may need fine-tuning. The grinding fine-tuning mechanism 41 can meet this precise adjustment requirement, ensuring optimal processing results at each processing stage.

[0057] In one embodiment of the present invention, such as Figure 4 As shown, the machine tool body 10 is provided with two return water holes 11, which are symmetrically arranged and located on both sides of the Z-axis hydrostatic guide rail hydrostatic unit 30 near the X-axis hydrostatic guide rail hydrostatic unit 20. A portion of the cooling water at the left end of the machine tool body 10 flows upward first, then to the right, and finally flows out through the upper return water hole 11; a portion of the cooling water at the right end of the machine tool body 10 flows upward first, then to the left, and finally flows out through the upper return water hole 11; similarly, a portion of the cooling water at the left end of the machine tool body 10 flows downward first, then to the right, and finally flows out through the lower return water hole 11; a portion of the cooling water at the right end of the machine tool body 10 flows downward first, then to the left, and finally flows out through the lower return water hole 11.

[0058] The symmetrically arranged return water holes 11 ensure a uniform flow path and flow rate distribution of cooling water on both sides of the machine tool body 10. This uniform cooling effect ensures that the heating conditions on both sides of the machine tool body 10 are consistent, avoiding local temperature differences caused by uneven cooling water flow. By using symmetrically arranged return water holes 11, the cooling water can uniformly remove the heat generated by the machine tool body 10 during processing, thereby effectively preventing thermal deformation caused by temperature differences and ensuring the structural stability of the machine tool body 10. In addition, in ultra-precision small-diameter optical grinding machines, micron-level machining accuracy is crucial. The symmetrically arranged return water holes 11 can ensure that the machine tool maintains stable machining accuracy during long-term operation and reduce machining errors caused by thermal deformation.

[0059] In one embodiment of the present invention, an acoustic emission sensor is provided on the workpiece hydrostatic spindle 70. The acoustic emission sensor is used to detect the AE signal of the grinding wheel. The acoustic emission sensor is electrically connected to the control cabinet 81. By detecting the AE signal of the grinding wheel through the acoustic emission sensor, functions such as rapid tool setting, anti-collision, and dressing detection can be realized. For example, during rapid tool setting, when the grinding wheel approaches the workpiece, a slight contact will cause a sudden increase in the acoustic emission signal. By detecting the amplitude jump or energy threshold of the AE signal, the contact moment is determined, and high-precision tool setting is achieved. Specifically, the grinding wheel rotates at a low speed and slowly approaches the workpiece. The AE sensor monitors the background noise in real time. When the signal exceeds a preset threshold, the feed is stopped immediately, and the current position is recorded as "zero point".

[0060] During the collision avoidance process, abnormal collisions (such as the grinding wheel impacting the fixture 71) will generate high-frequency AE pulse signals. By analyzing the burst energy or frequency characteristics of the signal (such as frequency domain resonance peaks), normal cutting and collisions can be distinguished. Specifically, a safety threshold (such as the AE RMS value) is set, and the signal is monitored in real time. If the threshold is exceeded and the duration is extremely short (milliseconds), an emergency stop is triggered, and the workpiece hydrostatic spindle 70 is shut down and retracted in conjunction with the machine tool control system.

[0061] During grinding wheel dressing, when the grinding wheel becomes dull or clogged, the RMS value of the AE signal decreases, but the high-frequency components increase (due to increased friction). During dressing, the contact between the dressing tool and the grinding wheel generates unique AE spectrum characteristics. Specifically, an AE baseline (such as the average RMS value) for normal grinding is established, and the signal is monitored in real time. If the RMS continues to decrease and the high-frequency energy increases, it is determined that the grinding wheel is dull. During dressing, the start / end point of dressing is identified through the AE signal to ensure consistent dressing amount.

[0062] In one embodiment of the present invention, the high-speed grinding spindle 50 is equipped with a grinding wheel axis. The coordinate point where the grinding wheel is clamped by the grinding wheel axis is located at the intersection of the axis of the high-speed grinding spindle 50 and the axis of the B-axis hydrostatic rotary table 40. This facilitates the software to accurately establish a tool database based on different grinding wheel types and sizes. This precise tool management method ensures that the position and orientation of the grinding wheel can be accurately recorded and recalled in different machining tasks, thereby improving the accuracy and repeatability of machining. Furthermore, when the cutting point is close to the center point of the B-axis hydrostatic rotary table 40, the torque of the B-axis hydrostatic rotary table 40 is more likely to meet the cutting torque generated by the grinding force. This design optimizes the transmission path of the cutting force, enabling the B-axis hydrostatic rotary table 40 to more effectively bear and transmit the grinding force during machining, thereby reducing machining errors and equipment wear caused by insufficient torque.

[0063] In one embodiment of the present invention, the linear motor of the hydrostatic guide rail hydrostatic unit 20 of the X-axis is electrically connected to the control cabinet 81. The control system can calculate the thrust of the linear motor by collecting the current signal of the linear motor, determine the dynamic imbalance of the workpiece hydrostatic spindle 70, and give the counterweight that needs to be added to the workpiece hydrostatic spindle 70, thereby realizing the dynamic balance adjustment of the workpiece hydrostatic spindle 70 on the vertical Y-axis 61.

[0064] In one embodiment of the present invention, the small-diameter optical grinding machine is equipped with an internal and external dual cooling system. The internal cooling system includes an internal circulation device and an external circulation device. The internal circulation device includes a high-precision variable frequency water cooler and a high-flow constant-temperature variable frequency water chiller. The high-precision variable frequency water cooler is used to monitor the oil temperature fluctuations at the outlet of the hydrostatic guide rail and the B-axis hydrostatic rotary table 40 in real time, controlling the temperature of key components affecting the accuracy of the machine tool system, and simultaneously providing cooling for the hydraulic oil of the workpiece hydrostatic spindle 70 and the servo motor of the vertical Y-axis 61. The high-flow constant-temperature variable frequency water chiller is used to cool the motor of the workpiece hydrostatic spindle 70 and the motor of the high-speed grinding spindle 50. The high-flow constant-temperature variable frequency water chiller also provides cooling for the external circulation device through a heat exchanger, for example, cooling the cutting fluid used for workpiece machining and providing overall machine tool water cooling. The cutting fluid filtration system is equipped with a heat exchanger, one end connected to the variable frequency water chiller and the other end connected to the filtered cutting fluid for cutting fluid cooling. A temperature sensor is installed at the outlet to monitor the cutting fluid outlet temperature, and the system temperature is manually adjusted to achieve equilibrium. The cutting fluid filtration system uses a combination of a high-speed centrifuge and a vertical paper tape filter, and is equipped with a pipeline filter. A variable frequency water chiller is used to cool the cutting fluid.

[0065] like Figures 6 to 9 As shown, the present invention also provides a processing technology for an ultra-precision small-diameter optical grinding machine with integrated polishing function. The processing technology is based on the ultra-precision small-diameter optical grinding machine with integrated polishing function described in any of the above embodiments, and includes:

[0066] For rough grinding and forming, firstly, a disc grinding wheel is used to roughen the inner spherical outer cantilever column, and then the disc grinding wheel is used to remove excess material beyond the outer diameter reference. Next, an inner contour grinding wheel for roughing is used to roughen the inner spherical surface. During this process, the B-axis hydrostatic turntable 40 needs to rotate to a fixed angle, thereby causing the grinding wheel rotation axis to form a fixed angle with the workpiece axis. The fixed angle is determined by calculating the workpiece dimensions. During the roughing of the inner spherical surface, the X-axis and Y-axis positions are fixed, and only the Z-axis needs to be fed. After the inner spherical surface is roughened, the disc grinding wheel is used to roughen the outer spherical outer cantilever column. Then, the B-axis hydrostatic turntable 40 rotates so that the angle between the grinding wheel axis and the workpiece axis is 90°. After the Z-axis feed drives the roughing outer contour grinding wheel to a certain position, the roughing of the outer spherical surface can be achieved by feeding only the X-axis. At this point, the hemispherical harmonic oscillator workpiece is initially formed.

[0067] Semi-finish grinding is performed using the inner spherical surface and inner cylindrical surface of the inner contour grinding wheel for semi-finishing; the outer spherical surface is semi-finished using the outer contour grinding wheel for semi-finishing. The rotation angle of the B-axis hydrostatic turntable 40 during semi-finishing of the inner and outer spherical surfaces is the same as the rotation angle of the B-axis hydrostatic turntable 40 during roughing of the inner and outer spherical surfaces. The outer cylindrical surface is then semi-finished using the disc grinding wheel.

[0068] Fine grinding is performed by using an inner contour grinding wheel for fine grinding of the inner spherical surface and the inner cylindrical surface, and by using an outer contour grinding wheel for fine grinding of the outer spherical surface. The rotation angle of the B-axis hydrostatic turntable 40 during fine grinding of the inner and outer spherical surfaces is the same as the rotation angle of the B-axis hydrostatic turntable 40 during rough grinding of the inner and outer spherical surfaces. Then, the outer cylindrical surface is finely ground by using the disc grinding wheel.

[0069] In each of the above processing steps, the grinding axis and the workpiece rotate around their own axes respectively;

[0070] The outer spherical column is cut off using a cutting grinding wheel to obtain the finished product;

[0071] After opening the clamp 71 and pulling the bar out to a predetermined length, the bar is then clamped back in place using the clamp 71.

[0072] Repeat the above steps until the bar stock is processed.

[0073] The processing technology of the ultra-precision small-diameter optical grinding machine with integrated polishing function provided by this invention uses a cup-shaped grinding wheel. After the B-axis hydrostatic turntable 40 is rotated to a certain angle and then fixed, the X-axis hydrostatic guide rail hydrostatic unit 20 and the Z-axis hydrostatic guide rail hydrostatic unit 30 move in coordination. For the characteristics of brittle optical materials, micron-level feed is used to achieve grinding of the inner and outer spherical surfaces of the hemispherical harmonic oscillator.

[0074] In one embodiment of the present invention, during the semi-finishing and finishing grinding steps, the end faces of both the inner and outer contour grinding wheels are obliquely intersecting the machined surface at a fixed angle α. Using this fixed angle α minimizes changes in the wheel axis oscillation angle during grinding. This stable machining posture helps maintain the contact accuracy between the grinding wheel and the workpiece, avoiding machining errors caused by excessive wheel axis oscillation, thereby improving machining accuracy and surface quality. Furthermore, this machining method ensures more uniform contact between the grinding wheel and the workpiece, further improving machining accuracy and surface quality. Especially when machining complex inner and outer spherical surfaces, this method effectively reduces machining marks and surface roughness, improving the overall performance of the workpiece.

[0075] The axis of the inner or outer contour grinding wheel intersects the axis of the workpiece at the center of the workpiece sphere. By aligning the axis of the grinding wheel with the axis of the workpiece at the center of the workpiece sphere, it is ensured that the grinding wheel maintains a relatively stable machining trajectory during wear. This machining method reduces manufacturing errors caused by grinding wheel wear, extends the service life of the grinding wheel, and reduces production costs and downtime caused by frequent grinding wheel replacements.

[0076] During machining, the workpiece hydrostatic spindle 70 drives the workpiece to rotate at a low speed around its own axis, while the high-speed grinding spindle 50 drives the grinding wheel to rotate at a high speed around its own axis. The envelope of the grinding wheel's grinding trajectory forms inner and outer spherical surfaces. This dual-axis rotation machining method allows the grinding wheel's grinding trajectory to more evenly cover the workpiece surface, improving machining efficiency. Simultaneously, by reducing the variation in the grinding wheel axis's oscillation angle, the machining process is more stable, reducing downtime caused by adjusting the grinding wheel's position.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-precision small-diameter optical grinding machine with integrated polishing function, characterized in that, include: Machine tool body (10); The main support frame assembly includes a main support frame body (90) and a plurality of air passive vibration isolators (91). The plurality of air passive vibration isolators (91) are vertically and spaced apart on the upper part of the main support frame body (90), and the upper ends of the plurality of air passive vibration isolators (91) are connected to the machine tool body (10). X-axis hydrostatic guide rail hydrostatic unit (20), the X-axis hydrostatic guide rail hydrostatic unit (20) is arranged along the X-axis on the upper part of the machine tool body (10); Z-axis hydrostatic guide rail hydrostatic unit (30), the Z-axis hydrostatic guide rail hydrostatic unit (30) is arranged along the Z-axis on the upper part of the machine tool body (10); B-axis hydrostatic rotary table (40), the B-axis hydrostatic rotary table (40) is disposed on the upper part of the Z-axis hydrostatic guide rail hydrostatic unit (30), the upper part of the B-axis hydrostatic rotary table (40) is provided with a high-speed grinding spindle (50), the B-axis hydrostatic rotary table (40) is used to drive the high-speed grinding spindle (50) to rotate around the B-axis, the high-speed grinding spindle (50) is used to install the grinding wheel and drive the grinding wheel to rotate around the C-axis; A vertical drive unit (60) is disposed on the upper part of the X-axis hydrostatic guide rail hydrostatic unit (20); The workpiece hydrostatic spindle (70) is located on one side of the vertical drive unit (60) and above the B-axis hydrostatic rotary table (40). The workpiece hydrostatic spindle (70) is equipped with a clamp (71), which is hollow inside and used to manually extract the bar stock. The clamp (71) holds the bar stock to process multiple workpieces from one bar stock. The vertical drive unit (60) is used to drive the workpiece hydrostatic spindle (70) to move along the Y-axis. The workpiece hydrostatic spindle (70) is equipped with an acoustic emission sensor, which is used to detect the AE signal of the grinding wheel. The acoustic emission sensor enables the machine tool to quickly set the tool and prevent collisions.

2. The ultra-precision small-diameter optical grinding machine with integrated polishing function according to claim 1, characterized in that, The vertical drive unit (60) includes: Mounting bracket (62), which is disposed on the upper part of the X-axis hydrostatic guide rail hydrostatic unit (20); A vertical Y-axis (61) is provided on one side of the mounting bracket (62). The slide of the vertical Y-axis (61) is connected to the workpiece hydrostatic spindle (70). The vertical Y-axis (61) is used to drive the workpiece hydrostatic spindle (70) to move along the Y-axis.

3. The ultra-precision small-diameter optical grinding machine with integrated polishing function according to claim 1, characterized in that, Also includes: Electrical control cabinet; An external support (80) is provided around the outer periphery of the main support frame assembly. An opening is provided on the upper part of the external support (80), and the machine tool body (10) extends out from the opening. The electrical control cabinet is located on the upper part of the external support (80).

4. The ultra-precision small-diameter optical grinding machine with integrated polishing function according to any one of claims 1 to 3, characterized in that, The upper part of the B-axis hydrostatic rotary table (40) is provided with a grinding fine adjustment mechanism (41), and the high-speed grinding spindle (50) is located on the upper part of the grinding fine adjustment mechanism (41).

5. The ultra-precision small-diameter optical grinding machine with integrated polishing function according to any one of claims 1 to 3, characterized in that, The machine tool body (10) is provided with two water return holes (11). The two water return holes (11) are arranged symmetrically and are located on both sides of the Z-axis hydrostatic guide rail hydrostatic unit (30) near the X-axis hydrostatic guide rail hydrostatic unit (20).

6. The ultra-precision small-diameter optical grinding machine with integrated polishing function according to any one of claims 1 to 3, characterized in that, An acoustic emission sensor is provided on the workpiece hydrostatic spindle (70), which is used to detect the AE signal of the grinding wheel.

7. The ultra-precision small-diameter optical grinding machine with integrated polishing function according to any one of claims 1 to 3, characterized in that, The high-speed grinding spindle (50) is equipped with a grinding wheel shaft, and the coordinate point where the grinding wheel is clamped by the grinding wheel shaft is located at the intersection of the axis of the high-speed grinding spindle (50) and the axis of the B-axis hydrostatic turntable (40).

8. A processing technology for an ultra-precision small-diameter optical grinding machine with integrated polishing function, said processing technology being based on the ultra-precision small-diameter optical grinding machine with integrated polishing function as described in any one of claims 1 to 7, characterized in that, include: For rough grinding and forming, firstly, the inner spherical outer cantilever column is roughened using a disc grinding wheel, and then the excess material outside the outer circle reference is removed using the disc grinding wheel; then, the inner spherical surface is roughened using an inner contour grinding wheel for roughing. During this process, the B-axis hydrostatic turntable (40) needs to be rotated to a fixed angle, thereby driving the grinding wheel rotation axis to form the fixed angle with the workpiece axis. The fixed angle is determined by calculating the workpiece size; during the roughing process of the inner spherical surface, the X-axis and Y-axis positions are fixed, and only the Z-axis needs to be fed; after the inner spherical surface is roughened, the outer spherical outer cantilever column is roughened using the disc grinding wheel; then, the B-axis hydrostatic turntable (40) rotates so that the fixed angle between the grinding wheel axis and the workpiece axis is 90°. After the Z-axis feed drives the roughing outer contour grinding wheel to a certain position, the roughing of the outer spherical surface can be achieved by only the X-axis feed. Thus, the hemispherical harmonic oscillator workpiece is initially formed. Semi-finish grinding is performed by using the inner spherical surface and inner spherical column of the inner contour grinding wheel for semi-finishing; the outer spherical surface is semi-finished by using the outer contour grinding wheel for semi-finishing. When semi-finishing the inner and outer spherical surfaces, the rotation angle of the B-axis hydrostatic turntable (40) is the same as the rotation angle of the B-axis hydrostatic turntable (40) when rough grinding the inner and outer spherical surfaces. Then, the outer spherical column is semi-finished by using the disc grinding wheel. Fine grinding is performed by using an inner contour grinding wheel for fine grinding to grind the inner spherical surface and the inner spherical column, and by using an outer contour grinding wheel for fine grinding to grind the outer spherical surface. When fine grinding the inner and outer spherical surfaces, the rotation angle of the B-axis hydrostatic turntable (40) is the same as the rotation angle of the B-axis hydrostatic turntable (40) when rough grinding the inner and outer spherical surfaces. Then, the outer spherical column is finely ground using the disc grinding wheel. In each of the above processing steps, the grinding axis and the workpiece rotate around their own axes respectively; The outer spherical column is cut off using a cutting grinding wheel to obtain the finished product; Open the clamp (71) to pull out the bar stock to a predetermined length, and then clamp the bar stock again through the clamp (71); Repeat the above steps until the bar stock is processed.

9. The processing technology of the ultra-precision small-diameter optical grinding machine with integrated polishing function according to claim 8, characterized in that, In the semi-finishing and finishing steps, the end faces of the inner contour grinding wheel and the outer contour grinding wheel are both obliquely intersecting the machined surface at a fixed angle α, and the axis of the inner contour grinding wheel or the outer contour grinding wheel intersects the axis of the workpiece at the center of the workpiece sphere.

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