Four-station double-turntable six-axis five-linkage optical grinding machine tool and processing method

Abstract

The application discloses a four-station double-rotary-table six-axis five-linkage optical grinding machine tool and a machining method, and relates to the technical field of grinding machining equipment. The machine tool comprises a three-axis moving assembly and a double-rotary-table component arranged on a machine tool base. A multi-spindle machining mechanism is connected to the output end of the three-axis moving assembly through a B-axis rotating component. The multi-spindle machining mechanism comprises four machining stations. The double-rotary-table component comprises an A-axis cradle component arranged on the machine tool base, and a C1-axis rotary table and a C2-axis rotary table connected to the output end of the A-axis cradle component. The C1-axis rotary table and the C2-axis rotary table are respectively used for carrying workpieces and mounting dressing tools. After clamping the workpieces to be machined on the rotary tables, different process machining can be carried out by using the multi-spindle machining mechanism, so that rough grinding, fine grinding and measurement and other whole-process machining can be completed in one clamping, and repeated clamping errors are effectively avoided. The double-rotary-table mechanism can adapt to the high-precision machining requirements of optical elements of different size ranges.

Description

Technical Field

[0001] This invention belongs to the technical field of grinding equipment, and relates to a four-station double rotary table six-axis five-linkage optical grinding machine and its processing method. Background Technology

[0002] Optical components play an irreplaceable and crucial role in numerous high-tech fields, including imaging systems, optical communications, laser processing, semiconductor manufacturing, biomedical testing, and aerospace. In recent years, with the rapid development of industrial technology, various applications have placed increasingly stringent demands on the surface accuracy, surface roughness, and subsurface damage depth of optical components. For example, the surface accuracy of aspherical lenses in deep ultraviolet lithography objectives, mirrors in high-energy laser systems, and large-size optical components in inertial confinement fusion devices often needs to reach sub-micron or even nanometer levels, and the surface roughness needs to be better than 1 nanometer.

[0003] However, the surface manufacturing of high-precision optical components is extremely difficult. Existing processing equipment and processes generally struggle to balance accuracy and efficiency. On the one hand, traditional optical grinding machine tools are mostly single-spindle or dual-spindle structures with relatively limited functionality. For the same workpiece, different processes such as rough grinding, semi-finish grinding, and finish grinding often need to be completed on different machine tools, or on the same machine tool through multiple manual tool changes. Each tool change or workpiece transfer involves re-clamping and alignment, introducing repeatability errors typically at the micrometer level, which directly becomes a bottleneck limiting further improvements in final machining accuracy. At the same time, frequent loading, unloading, and alignment operations severely disrupt the continuous machining process, resulting in low overall production efficiency and making it difficult to meet the demands of mass production.

[0004] On the other hand, there is currently a lack of CNC grinding equipment that can maturely integrate multiple machining tools (such as grinding wheels of different grit sizes, polishing tools, in-situ measurement probes, etc.) and achieve multi-process composite machining in a single setup. Most existing machine tools can only accommodate one or two machining tools. When it is necessary to use grinding wheels of different shapes or grit sizes for roughing and finishing separation, or to combine in-situ measurement for closed-loop accuracy control, it is often impossible to achieve this due to insufficient tool magazine capacity or complex tool changing mechanisms. This lack of functional integration not only exacerbates repeated clamping errors but also limits the high-precision forming capabilities of complex curved surfaces (such as free-form surfaces, off-axis aspherical surfaces, hemispherical harmonic oscillators, X-ray mirrors, etc.). This is because the machining of complex curved surfaces usually requires multiple grinding wheels of different geometries (such as cup-shaped grinding wheels, disc-shaped grinding wheels, and arc-shaped grinding wheels) in conjunction with multi-axis linkage to achieve complete surface creation. Frequent manual tool changes or process transfers can easily damage the established multi-axis linkage coordinate reference, making it difficult to meet the design requirements for final machining accuracy.

[0005] In summary, existing optical grinding equipment generally suffers from technical problems such as poor machining accuracy, low efficiency due to frequent clamping, low functional integration, and insufficient ability to process complex curved surfaces. Summary of the Invention

[0006] To address the problems of low machining accuracy, frequent clamping, low machining efficiency, and low integration of machining methods in existing grinding machine tools, this invention provides a four-station dual-rotary-table six-axis five-linkage optical grinding machine and machining method, which uses multiple machining methods to achieve high-quality, high-efficiency, and ultra-precision grinding of optical components.

[0007] This invention is achieved through the following technical solution: A four-station, dual-rotary-table, six-axis, five-linkage optical grinding machine tool, comprising: Machine tool base, and a three-axis moving assembly and a dual rotary table assembly mounted on the machine tool base; The output end of the three-axis moving component is connected to a multi-spindle machining mechanism via a B-axis rotating component. The multi-spindle machining mechanism is provided with four machining stations, each including three machining ends and one detection end. The axis position of the B-axis rotating component is set within the range of the center of gravity variation of the multi-spindle machining mechanism. The dual rotary table component includes an A-axis cradle component mounted on the machine tool base, and a C1-axis rotary table and a C2-axis rotary table connected to the output end of the A-axis cradle component. The C1-axis rotary table and the C2-axis rotary table are respectively used to support the workpiece and to install the dressing tool. The axes of the three-axis moving assembly, the A-axis of the A-axis cradle component, the B-axis of the B-axis rotating component, and the C1-axis of the C1-axis turntable work together to complete different processing steps or in-situ measurements.

[0008] Preferably, the three-axis moving assembly includes a Y-axis moving component disposed on the machine tool base, an X-axis moving component disposed on the Y-axis moving component, and a Z-axis moving component disposed on the X-axis moving component; the B-axis rotating component is disposed on the Z-axis moving component.

[0009] Preferably, the Y-axis moving component includes a Y-axis slide rail mounted on the machine tool base along the Y-axis direction and a Y-axis slide block slidably disposed on the Y-axis slide rail; The X-axis moving component includes an X-axis slide rail mounted on the Y-axis slide block along the X-axis direction and an X-axis slide block slidably disposed on the X-axis slide rail; The Z-axis moving component includes a Z-axis slide rail mounted on the X-axis slide along the Z-axis direction and a Z-axis slide slidably disposed on the Z-axis slide rail; the B-axis rotating component is disposed on the Z-axis slide.

[0010] Preferably, the multi-spindle machining mechanism includes a mounting frame, a spindle base mounted on the mounting frame, a multi-station grinding spindle mounted on the spindle base, and a probe fixedly mounted on the side of the mounting frame; The multi-station grinding spindle includes a first spindle, a second spindle, and a third spindle; the first spindle and the second spindle are coaxial and arranged in opposite directions, and the coaxial axis of the first spindle and the second spindle is perpendicular to the movement direction of the Y-axis moving component; the axis of the third spindle is perpendicular to the axes of the first spindle and the second spindle, and the direction of the axis of the third spindle is parallel to the movement direction of the Y-axis moving component.

[0011] Preferably, the spindle base specifically includes a first base and a second base; the first spindle and the second spindle are coaxially mounted on the first base in opposite directions; The second base is fixedly mounted on one side of the mounting surface of the first base, and the third spindle is mounted on the second base; the probe is mounted on the other side of the mounting surface of the first base, which is opposite to the third spindle.

[0012] Preferably, the A-axis cradle component includes a cradle frame, an A-axis support base, and a tool setter; the cradle frame is swayably mounted on the A-axis support base; the tool setter is mounted on the cradle frame; and the A-axis support base is mounted on the machine tool base.

[0013] Preferably, the C1 axis turntable is located at the center of the cradle frame, and the C1 axis turntable includes a C1 axis base mounted on the cradle frame and a first air-bearing turntable disposed on the C1 axis base; The C2 axis turntable is mounted on the cradle frame and located on one side of the C1 axis turntable; the C2 axis turntable includes a C2 axis base mounted on the cradle frame and a second air-bearing turntable mounted on the C2 axis base.

[0014] A machining method for a four-station, dual-rotary-table, six-axis, five-linkage optical grinding machine includes the following steps: Before machining the workpiece, the axis position of the B-axis rotating component is set within the range of the center of gravity variation of the multi-spindle machining mechanism; then, the structural dimensional error between the B-axis axis and the first and second spindles is compensated by trial cutting the workpiece. After compensation, the workpiece to be processed is mounted on the C1 axis rotary table; The three-axis moving assembly can achieve five-axis linkage with the A-axis on the A-axis cradle component and the C1-axis on the C1-axis turntable; or, the three-axis moving assembly can achieve five-axis linkage with the B-axis on the B-axis rotating component and the C1-axis on the C1-axis turntable, thereby controlling the multi-spindle machining mechanism to perform rough grinding, semi-fine grinding, and fine grinding on the workpiece. During the machining process, different processes or in-situ measurements are completed by rotating the multi-spindle machining mechanism; The dressing tool mounted on the C2 axis rotary table is used to dress the grinding wheel on the multi-spindle machining mechanism in place.

[0015] Preferably, the axial position of the B-axis rotating component is set within the range of the center of gravity variation of the multi-spindle machining mechanism, specifically: Establish the center of gravity of the multi-spindle machining mechanism using the origin of any coordinate system as a reference. , , The expression for ) is as follows:

[0016] in, To ensure the quality of multi-spindle machining mechanisms without installing any grinding wheels, The mass of the grinding wheel mounted on the first spindle. The mass of the grinding wheel mounted on the second spindle. The mass of the grinding wheel mounted on the third spindle; The coordinates of the center of gravity of the multi-spindle machining mechanism under no-load conditions; The coordinates of the center of gravity of the grinding wheel mounted on the first spindle are ( ( ) represents the coordinates of the center of gravity of the grinding wheel mounted on the second spindle; () represents the coordinates of the center of gravity of the grinding wheel mounted on the third spindle; Based on the expression for the center of gravity of the multi-spindle machining mechanism, the overall center of gravity coordinates of the multi-spindle machining mechanism under different grinding wheel load combinations are calculated to obtain the range of center of gravity variation of the multi-spindle machining mechanism. The axis position of the B-axis rotating component is set within the center of gravity variation range of the multi-spindle machining mechanism.

[0017] Preferably, the structural dimensional error between the B-axis and the first and second spindles is compensated by trial cutting the workpiece, specifically as follows: Move the multi-spindle machining mechanism above the test-cut workpiece, so that the center of the multi-spindle machining mechanism is at the theoretical distance above the workpiece surface. At this point, due to the actual structural dimensions between the B-axis axis and the first spindle end face... Manufacturing and assembly errors exist, resulting in vertical structural dimensional errors. ; Structural dimensional error in the vertical direction Obtain the actual structural dimensions in the vertical direction. Actual structural dimensions in the horizontal direction Specifically: By oscillating only the B-axis, the grinding wheel is machined into a spherical surface on the test-cut workpiece, and the actual radius of the sphere is measured. When machining a spherical surface, with the B-axis as the center of rotation, the sum of the distance from the B-axis to the center of the arc of the grinding wheel and the radius of the arc of the grinding wheel should equal the actual radius of the spherical surface being machined. The specific expression is as follows:

[0018] Among them, the actual structural dimensions in the vertical direction The specific expression is:

[0019] Obtain the actual structural dimensions in the horizontal direction The specific expression is:

[0020] In the formula: This refers to the actual dimension in the x-direction between the B-axis and the first main axis, which is the actual structural dimension in the horizontal direction. This is the actual dimension in the z-direction between the B-axis axis and the end face of the first spindle. The actual radius of the sphere obtained from the trial cut of the workpiece. The median diameter of the grinding wheel. Let be the radius of the arc of the grinding wheel. The height of the grinding wheel; This is the theoretical dimension in the z-direction between the B-axis axis and the end face of the first spindle. Based on the actual structural dimensions in the vertical direction Actual structural dimensions in the horizontal direction This enables compensation for structural dimensional errors between the B-axis and the first and second main axes.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects: The four-station, dual-rotary-table, six-axis, five-linkage optical grinding machine provided by this invention, by setting a three-axis moving assembly, a B-axis rotating component, and a multi-spindle machining mechanism on the machine tool base, and by setting the axis position of the B-axis rotating component within the range of the center of gravity variation of the multi-spindle machining mechanism, can effectively reduce the eccentric torque caused by the center of gravity shift during the indexing rotation of the B-axis, thereby significantly improving the rotational accuracy and motion stability of the B-axis; by setting four machining stations including three machining ends and one detection end on the multi-spindle machining mechanism, after the workpiece is clamped once, different machining ends and detection ends can be switched sequentially by rotating the B-axis rotating component to index, continuously completing multiple machining processes and in-situ measurements, thereby eliminating the repetitive positioning errors introduced by multiple clamping, and effectively improving machining accuracy and efficiency; by setting A The A-axis cradle assembly connects to a C1-axis rotary table for carrying the workpiece and a C2-axis rotary table for mounting dressing tools at its output end. This enables parallel configuration of workpiece machining and grinding wheel dressing, allowing in-situ dressing of the grinding wheel without disassembly, further ensuring accuracy stability during long-term machining. Simultaneously, through the linkage of the axes of the three-axis moving assembly with the spindle of the B-axis rotating component and the spindle of either the C1-axis or C2-axis rotary table, various five-axis linkage machining modes can be formed. This allows for high-precision, high-efficiency ultra-precision grinding of various complex optical components such as spherical, aspherical, freeform, hemispherical resonators, and X-ray mirrors. The in-situ dressing of the grinding wheel via the C2-axis rotary table demonstrates broad application prospects in the optical manufacturing field. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is an isometric view of the four-station dual-rotary-table six-axis five-linkage optical grinding machine tool of the present invention; Figure 2 This is a schematic diagram of the structure of the grinding machine tool of the present invention; Figure 3 This is a schematic diagram of the multi-spindle machining mechanism of the present invention; Figure 4 This is a schematic diagram of the structure of the A-axis cradle component of the present invention; Figure 5 This is a schematic diagram illustrating the compensation for structural dimensional errors in the z-direction according to the present invention. Figure 6 This is a schematic diagram of the dimensional error compensation structure for the trial cutting of the present invention; Figure 7 This is a schematic diagram of the spherical surface machining process using the cradle turntable linkage mode (linkage between axis A and axis C1) of the present invention; Figure 8 This is a schematic diagram illustrating the machining of aspherical surfaces using the cradle turntable linkage mode (linkage between A-axis and C1-axis) of the present invention. Figure 9 This is a schematic diagram illustrating the machining of freeform surfaces using the cradle turntable linkage mode (linkage between A-axis and C1-axis) of the present invention. Figure 10 This is a schematic diagram of the hemispherical harmonic oscillator fabricated using the cradle turntable linkage mode (linkage between A-axis and C1-axis) according to the present invention. Figure 11 This is a schematic diagram illustrating the machining of spherical surfaces using a rotary table linkage mode (linkage between axis B and axis C1) according to the present invention. Figure 12 This is a schematic diagram illustrating the machining of aspherical surfaces using the rotary table linkage mode (linkage between B-axis and C1-axis) of this invention. Figure 13 This is a schematic diagram illustrating the machining of freeform surfaces using a rotary table linkage mode (linkage between B-axis and C1-axis) according to the present invention. Figure 14 This is a schematic diagram of the X-ray mirror grinding using a disc grinding wheel in the swing head turntable linkage mode (linkage between B axis and C1 axis) of the present invention. Figure 15 This is a schematic diagram illustrating the in-situ dressing of the grinding wheel on the spindle using a dressing tool mounted on the C2 axis according to the present invention. Figure 16 This is a schematic diagram of the invention using a third spindle to mount a disc grinding wheel for semi-finish grinding; Figure 17 This is a schematic diagram of the present invention using a cup-shaped grinding wheel mounted on a second spindle for precision grinding; Figure 18 This is a schematic diagram illustrating in-situ measurement using a probe according to the present invention; Reference numerals: 1-Outer casing, 2-Observation window, 3-Grinding fluid recovery channel, 4-Fine filter water tank, 5-Machine base, 6-Y-axis motor, 7-Y-axis slide rail, 8-Y-axis slide block, 9-X-axis motor, 10-X-axis slide rail, 11-X-axis slide block, 12-Z-axis motor, 13-Z-axis slide rail, 14-Z-axis slide block, 15-Mounting bracket, 16-First base, 17-Second base, 18-First spindle, 19- 20-Second spindle, 21-Third spindle, 22-Probe, 23-Coolant inlet, 24-C1 axis base, 25-C2 axis base, 26-First air-bearing rotary table, 27-Second air-bearing rotary table, 28-Tool setter, 29-A-axis support, 30-Spherical workpiece, 31-Aspherical workpiece, 32-Freeform surface workpiece, 33-Hemispherical harmonic oscillator, 34-X-ray mirror, 35-Dressing tool. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] This invention provides a four-station, dual-rotary-table, six-axis, five-linkage optical grinding machine. By integrating multiple motor axes such as X-axis, Y-axis, Z-axis, A-axis, B-axis, C1-axis, and C2-axis, a four-station, dual-rotary-table, six-axis, five-linkage optical grinding machine is constructed. This enables the machine to have two processing modes: cradle-table linkage (A-axis + C1-axis) and swivel-table linkage (B-axis + C1-axis). It can achieve high-precision and high-efficiency ultra-precision grinding of complex surface optical components such as spherical surfaces, aspherical surfaces, freeform surfaces, hemispherical harmonic oscillators, and X-ray mirrors. All motion axes of this four-station, dual-rotary-table, six-axis, five-linkage optical grinding machine are controlled by a CNC system.

[0026] In this invention, to facilitate a clear description of the relative motion relationships between the moving parts, the motion axes of the machine tool are defined as follows: X-axis: Defined as a linear motion axis set in the horizontal direction, its direction is perpendicular to the Y-axis and Z-axis, and it is driven by the X-axis motor 9 to translate the X-axis slide 11 along the X-axis slide rail 10.

[0027] Y-axis: Defined as a linear motion axis set in the horizontal direction, its direction is perpendicular to the X-axis and Z-axis, and the Y-axis slide 8 is driven by the Y-axis motor 6 to translate along the Y-axis slide rail 7.

[0028] Z-axis: Defined as a linear motion axis set in the vertical direction, its direction is perpendicular to the X-axis and Y-axis, and it is driven by Z-axis motor 12 to move Z-axis slide 14 along Z-axis slide rail 13.

[0029] A-axis: Defined as a rotary motion axis that rotates around the X-axis direction, driven by the A-axis drive mechanism to swing the cradle frame 23 around the A-axis support 29.

[0030] B-axis: Defined as a rotary motion axis that rotates around the Y-axis. The multi-spindle machining mechanism is driven by the B-axis rotating component to swing around the B-axis axis.

[0031] C1 axis: defined as a rotary motion axis that rotates around the Z-axis, driven by the first air-bearing turntable 26 to rotate the workpiece around the vertical axis of the C1 axis base 24.

[0032] C2 axis: defined as a rotary motion axis that rotates around the Z-axis. The dressing tool is driven by the second air-bearing turntable 27 to rotate around the vertical axis of the C2 axis base 25. The C2 axis is in the same direction as the C1 axis and is arranged side by side on the cradle frame 23.

[0033] In this invention, the X-axis, Y-axis, and Z-axis are three mutually orthogonal linear motion axes; the A-axis is a swing axis that rotates around the X-axis and drives the cradle frame to swing; the B-axis is a swing axis that rotates around the Y-axis and drives the multi-spindle machining mechanism to swing; and the C1-axis is a rotary axis that rotates around the Z-axis and drives the workpiece turntable to rotate.

[0034] During machining, the X, Y, Z, A, B, and C1 axes together constitute six controllable motion axes. Among them, the C2 axis is dedicated to grinding wheel dressing and does not participate in the workpiece's simultaneous grinding process. Therefore, the machine tool can achieve two different five-axis simultaneous machining modes depending on the workpiece's surface shape requirements: The first type is the cradle turntable linkage mode, which involves five-axis linkage between three linear axes (X-axis, Y-axis, and Z-axis) and two rotary axes (A-axis and C1-axis). The A-axis swings to change the workpiece's posture, and the C1-axis rotates to rotate the workpiece. Combined with the translational motion of the three linear axes, five-axis linkage machining is achieved. This is suitable for grinding complex curved surfaces of rotation such as spherical surfaces, aspherical surfaces, and hemispherical harmonic oscillators.

[0035] The second type is the rotary table linkage mode, which involves five-axis linkage between three linear axes (X-axis, Y-axis, and Z-axis) and two rotary axes (B-axis and C1-axis). The B-axis swings to change the posture of the grinding wheel, and the C1-axis rotates to rotate the workpiece. Combined with the translational motion of the three linear axes, five-axis linkage machining is achieved. This is suitable for grinding high-precision non-rotational symmetrical surfaces such as free-form surfaces and X-ray mirrors.

[0036] like Figures 1 to 4 As shown, the four-station double rotary table six-axis five-linkage optical grinding machine tool includes a grinding machine body, a housing 1, and a fine filter water tank 4. The grinding machine body includes a machine tool base 5, a Y-axis moving component mounted on the machine tool base 5, an X-axis moving component mounted on the Y-axis moving component, a Z-axis moving component mounted on the X-axis moving component, a multi-spindle machining mechanism mounted on the Z-axis moving component, and a double rotary table component mounted on the machine tool base 5. By utilizing this full-axis linkage configuration, the technical defects of existing grinding machine tools, such as frequent clamping, low processing efficiency, and low integration of processing methods, can be effectively solved. The outer casing 1 is located outside the grinding machine body. A grinding fluid recovery channel 3 is provided on the left side of the outer casing 1, and the grinding fluid recovery channel 3 is connected to the grinding machine body.

[0037] The fine filtration water tank 4 is located on the left side of the outer casing 1, and the water tank of the fine filtration water tank 4 is located below the grinding fluid recovery channel 3.

[0038] Specifically, each axis moving component realizes the five-axis linkage machining function, the workpiece to be processed is placed on the double turntable, the multi-spindle machining mechanism performs workpiece processing, and the used grinding fluid enters the fine filter water tank 4 from the bottom of the machine tool base 5 through the grinding fluid recovery channel 3.

[0039] like Figure 2 As shown, the Y-axis moving component includes a Y-axis slide rail 7 and a Y-axis slide block 8. The Y-axis slide rail 7 is horizontally fixedly mounted on the machine tool base 5, and the Y-axis slide block 8 is slidably mounted on the Y-axis slide rail 7. The bottom end of the Y-axis slide block 8 is connected to a Y-axis ball screw, and the input end of the Y-axis ball screw is connected to a Y-axis motor 6. The Y-axis motor 6 drives the Y-axis slide block 8 to perform translational movement along the Y-axis slide rail 7.

[0040] The X-axis moving component includes an X-axis slide rail 10 and an X-axis slide block 11. The X-axis slide rail 10 is horizontally mounted on the top surface of the Y-axis slide block 8 (its extension direction is perpendicular to the Y-axis slide rail 7). The X-axis slide block 11 is slidably mounted on the X-axis slide rail 10 via a slider, and the X-axis slide block 11 is connected to an X-axis ball screw. The input end of the X-axis ball screw is connected to an X-axis motor 9, which drives the X-axis slide block 11 to achieve translational movement along the X-axis direction.

[0041] The Z-axis moving component includes a Z-axis slide rail 13 and a Z-axis slide block 14. The Z-axis slide rail 13 is fixedly mounted on the X-axis slide block 11 in the vertical direction; the Z-axis slide block 14 is slidably mounted on the Z-axis slide rail 13 via a slider. That is, in this embodiment, the X-axis slide block 11 is simultaneously connected to both the X-axis slide rail 10 and the Z-axis slide rail 13, thereby forming a compact three-dimensional translational interlocking structure. The Z-axis slide block 14 is connected to a vertically arranged Z-axis ball screw, the input end of which is connected to a Z-axis motor 12, which drives the Z-axis slide block 14 to translate along the Z-axis direction (vertical direction).

[0042] Specific spatial arrangement and indexing architecture of multi-spindle machining mechanisms, such as Figure 2 and Figure 3 As shown; The front end face of the Z-axis slide 14 is provided with a B-axis rotating component. The B-axis rotating component includes a B-axis support, a B-axis stator, and a B-axis rotor. The B-axis support is mounted on the Z-axis slide 14 and serves as the fixed base for the B-axis rotating component. The B-axis stator is fixedly installed inside the B-axis support, and the B-axis rotor is rotatably mounted on the B-axis support and cooperates with the B-axis stator. The multi-spindle machining mechanism is fixedly connected to the output end of the B-axis rotor and is driven by the B-axis rotor to achieve overall angular swing indexing as the B-axis rotates.

[0043] The multi-spindle machining mechanism includes a mounting frame 15, a spindle base mounted on the mounting frame 15, a multi-station grinding spindle mounted on the spindle base, and a probe 21 fixedly mounted on the side of the mounting frame 15. The multi-station grinding spindle includes a first spindle 18, a second spindle 19, and a third spindle 20. The mounting frame 15 is provided with four functional stations that are equally spaced at 90° intervals. The four functional stations correspond to the first spindle 18, the second spindle 19, the third spindle 20, and the probe 21, respectively. The spindle base specifically includes a first base 16 and a second base 17; a first spindle 18 and a second spindle 19 are coaxially mounted on the first base 16 in parallel and opposite directions; the common axis of the first spindle 18 and the second spindle 19 is perpendicular to the movement direction of the Y-axis moving component; the second base 17 is fixedly mounted on one side of the mounting surface of the first base 16, and a third spindle 20 is mounted on it, the axial direction of the third spindle 20 being parallel to the movement direction of the Y-axis moving component. Thus, the spindle directions of the first spindle 18 and the second spindle 19 are orthogonally perpendicular to the direction of the third spindle 20 in three-dimensional space. The third spindle 20 is used to mount a disc grinding wheel, and uses the circumferential surface (i.e., the side surface) of the grinding wheel as the working surface to grind the side, end, or planar features of the workpiece; a probe 21 is mounted on the other side of the mounting surface of the first base 16 opposite to the third spindle 20, its measurement direction being parallel to the Y-axis direction, for in-situ measurement.

[0044] In this embodiment, the first spindle 18, the second spindle 19, the third spindle 20, and the probe 21 are arranged circumferentially on the four outer surfaces of the multi-spindle machining mechanism. Preferably, the first spindle 18, the second spindle 19, the third spindle 20, and the probe 21 are distributed at 90° intervals. The first spindle 18 and the second spindle 19 are respectively equipped with coarse grinding wheels and fine grinding wheels. The third spindle 20 is used to mount disc-shaped or disk-shaped grinding wheels for machining large flat surfaces or performing semi-fine grinding. The probe 21 is used for in-situ dimensional measurement. The mounting frame 15 is also provided with a coolant inlet 22 for receiving grinding fluid flowing from the tube into the machining area during grinding. In the four-station multi-spindle machining mechanism designed in this invention, the first spindle and the second spindle are coaxially and oppositely arranged, and perpendicular to the third spindle, and the probe is integrated. The four stations are distributed at 90° intervals. After the workpiece is clamped once on the C1 axis turntable, it can be indexed and rotated on the B axis to sequentially switch between coarse grinding wheels, fine grinding wheels, disc or disk grinding wheels and in-situ measuring heads to continuously complete multiple processes such as coarse grinding, semi-fine grinding, fine grinding and in-situ measurement. This effectively eliminates repeated clamping errors and significantly improves machining accuracy and efficiency.

[0045] To ensure the stability of the B-axis rotational indexing torque during ultra-precision machining, this embodiment incorporates a center-of-gravity optimization control design for the multi-spindle machining mechanism: Because the three spindles of a multi-spindle machining mechanism are each equipped with grinding wheels of different weights and overhang lengths, the differences in the weight and overhang length of these grinding wheels will cause nonlinear changes in the load torque on the B-axis. As the machining process changes, the overall center of gravity of the multi-spindle machining mechanism will shift. If the axis of the B-axis deviates from the center of gravity, the B-axis will experience a large eccentric torque during indexing, affecting indexing accuracy and motion stability.

[0046] To this end, the present invention establishes a mathematical model of the center of gravity of a multi-spindle machining mechanism, calculates the range of changes in the center of gravity coordinates under different combinations of grinding wheel loads, and sets the axis position of the B-axis rotating component within the range of changes in the center of gravity of the multi-spindle machining mechanism.

[0047] Specifically: using the origin of any coordinate system as a reference, establish the center of gravity of the multi-spindle machining mechanism ( , , The expression for ) is used as the centroid mathematical model, specifically:

[0048] in, To ensure the quality of multi-spindle machining mechanisms without installing any grinding wheels, The mass of the grinding wheel mounted on the first spindle. The mass of the grinding wheel mounted on the second spindle. The mass of the grinding wheel mounted on the third spindle; The coordinates of the center of gravity of the multi-spindle machining mechanism under no-load conditions; The coordinates of the center of gravity of the grinding wheel mounted on the first spindle are ( ( ) represents the coordinates of the center of gravity of the grinding wheel mounted on the second spindle; () represents the coordinates of the center of gravity of the grinding wheel mounted on the third spindle; Based on the expression for the center of gravity of the multi-spindle machining mechanism, the overall center of gravity coordinates of the multi-spindle machining mechanism under different grinding wheel load combinations are calculated to obtain the range of center of gravity variation of the multi-spindle machining mechanism. The axis position of the B-axis rotating component is set within the center of gravity variation range of the multi-spindle machining mechanism.

[0049] The CNC system automatically calculates the actual center of gravity under the current load based on the above formula, and optimizes the driving force of the B-axis motor accordingly, thereby reducing the negative torque disturbance caused by the weight of the grinding wheels on each spindle and the load changes on the B-axis movement.

[0050] The specific mechanical structure of the dual turntable components is as follows: Figure 4As shown: The dual rotary table assembly is integrally mounted on the machine tool base 5, including an A-axis cradle assembly and C1-axis and C2-axis rotary tables arranged side-by-side on the A-axis cradle assembly. The C1-axis rotary table is used to support workpieces of different sizes, and in conjunction with a multi-spindle machining mechanism, it enables stable machining of large-sized optical components. Simultaneously, the C2-axis rotary table can be equipped with a grinding wheel dressing tool to perform in-situ dressing of the grinding wheels on the spindle, further ensuring the accuracy and stability of long-term machining.

[0051] The A-axis cradle assembly includes a cradle frame 23, a tool setter 28, and an A-axis support 29. The A-axis support 29 is fixed on the machine tool base 5, and the cradle frame 23 is rotatably mounted on the A-axis support 29 to achieve A-axis swing. The tool setter 28 is fixedly mounted on the cradle frame 23 for tool setting.

[0052] Among them, there are two A-axis support seats 29, which are fixedly installed on the machine tool base 5 along the X-axis direction of the machine tool; the cradle frame 23 is mounted between the two A-axis support seats 29, and the two ends of the cradle frame 23 are rotatably mounted on the two A-axis support seats 29 through high-precision bearing assemblies, thereby realizing swinging around the A-axis axis. The tool setting device 28 is fixedly installed on a suitable position on the side wall or top of the cradle frame 23 (e.g., Figure 4 As shown, this is used to perform in-situ contact-triggered measurements of the axial position and radial dimension of the grinding wheel after switching spindles or changing grinding wheels in a multi-spindle machining mechanism, ensuring the consistency of the machining datum after each station switch.

[0053] The C1 axis turntable refers to the first air-bearing rotary table set at the center of the cradle frame 23, including the C1 axis base 24 and the first air-bearing turntable 26, which is used to carry the workpiece and realize the rotational movement of the C1 axis. The C1 axis base 24 is fixedly installed on the cradle frame 23. The air-bearing spindle of the first air-bearing turntable 26 is supported by a hydrostatic air bearing, directly driven by a built-in torque motor, and equipped with a high-resolution circular grating encoder, which is used to carry the workpiece (i.e., the optical element to be processed) and drive the workpiece to perform high-precision rotational movement around the vertical direction (i.e., the Z-axis direction).

[0054] The C2 axis rotary table refers to the second air-bearing rotary worktable mounted on the cradle frame 23 and located on one side of the C1 axis rotary table. It includes a C2 axis base 25 and a second air-bearing rotary table 27, used to mount dressing tools and realize the rotational movement of the C2 axis. The C2 axis base 25 is fixedly mounted on the cradle frame 23. The structure of the second air-bearing rotary table 27 is the same as that of the first air-bearing rotary table 26, used to mount the dressing tool 35 of the grinding wheel and drive the dressing tool to rotate around the vertical direction (i.e., the Z-axis direction). The C2 axis rotary table has the same structure as the C1 axis rotary table. Both the C1 axis and C2 axis refer to the motion axes that rotate around the vertical direction (Z-axis direction). In one preferred embodiment, during actual processing, the first air-bearing turntable 26 of the C1-axis turntable is used to clamp and fix the optical element to be processed, while the C2-axis turntable is used to install the dressing tool 35 for dressing the grinding wheel. When the grinding wheel on the multi-spindle machining mechanism develops shape errors due to prolonged grinding, the multi-spindle machining mechanism moves above the C2-axis turntable, and the dressing tool 35 on the C2-axis turntable is used to dress the grinding wheel in place without disassembling the grinding wheel, thus ensuring shape accuracy.

[0055] Based on hardware center of gravity optimization, in order to eliminate assembly and manufacturing dimensional errors between the B-axis axis and the first spindle 18 and the second spindle 19, this embodiment provides a trial-cut in-situ compensation control method. This method obtains the actual structural dimensions by trial-cutting the workpiece, compensates for the position of the B-axis axis, and compensates for the structural dimensional errors (including vertical and horizontal structural dimensional errors) between the B-axis axis and the first and second spindles. The specific principle and steps are as follows: like Figure 5 As shown, the multi-spindle machining mechanism is moved above the test-cut workpiece, so that the center of the multi-spindle machining mechanism is located at the theoretical distance above the surface of the test-cut workpiece. At this location, the theoretical distance is calculated based on the design dimensions, where, This represents the theoretical dimension in the z-direction between the B-axis and the end face of the first spindle. The height of the grinding wheel; Ideally, the grinding wheel should be flush with the surface of the workpiece being tested. However, due to the actual structural dimensions between the B-axis and the end face of the first spindle... Manufacturing and assembly errors cause a deviation between the actual and theoretical positions of the grinding wheel; this deviation manifests as a vertical dimensional error. .

[0056] If the grinding wheel does not touch the surface of the test-cut workpiece, control the grinding wheel to move downwards along the Z-axis until it touches the surface. Use the CNC system to record the actual distance the grinding wheel moves; this distance is the vertical structural dimensional error. If the grinding wheel touches below the surface of the test-cut workpiece, the depth to which the grinding wheel removes material is measured, thus obtaining the vertical structural dimensional error. ; Obtaining the structural dimensional error in the vertical direction Based on this, the actual structural dimensions in the horizontal direction (X-axis direction) are further obtained. To compensate for horizontal structural dimensional errors, specifically, such as Figure 6 As shown, only the B-axis is oscillated to allow the grinding wheel to machine a spherical surface on the test-cut workpiece, and the actual radius of the sphere is measured. When machining a spherical surface, the B-axis is the center of rotation. Based on the grinding wheel's mounting dimensions, the sum of the distance from the B-axis to the center of the grinding wheel's arc and the radius of the grinding wheel's arc should equal the actual radius of the spherical surface being machined. The expression based on this geometric relationship is:

[0057] in, This represents the actual x-axis dimension between the B-axis and the first spindle axis. This is the actual dimension in the z-direction between the B-axis axis and the end face of the first spindle. The actual radius of the sphere obtained from the trial cut of the workpiece. The median diameter of the grinding wheel. Let be the radius of the arc of the grinding wheel. The height of the grinding wheel; Among them, the actual structural dimensions in the vertical direction Vertical structural dimensional errors can be addressed. The specific expression is:

[0058] The actual structural dimensions in the horizontal direction (X-axis direction) can be obtained by refining the data. The specific expression is:

[0059] In the formula: Δ z The error between the actual and theoretical dimensions in the z-direction from the B-axis axis to the end face of the first spindle is the structural dimensional error in the vertical direction. , This is the theoretical dimension in the z-direction between the B-axis axis and the end face of the first spindle. The actual radius of the sphere obtained from the trial cut of the workpiece. The median diameter of the grinding wheel. Let be the radius of the arc of the grinding wheel. The height of the grinding wheel is defined as follows: The pitch diameter of the grinding wheel refers to the center diameter of the working surface; the radius of curvature of the grinding wheel refers to the radius of the fillet created by dressing the edge of the working surface; and the height of the grinding wheel refers to its thickness along the spindle axis (i.e., the Z-axis direction). Based on the actual structural dimensions in the vertical direction Actual structural dimensions in the horizontal direction This enables compensation for structural dimensional errors between the B-axis and the first and second main axes.

[0060] Since the first spindle 18 and the second spindle 19 are coaxially and oppositely arranged, they share the same axis. The B-axis axis position compensation amount (i.e., obtained through trial cutting of the first spindle) is calculated based on the position compensation amount of the B-axis axis obtained through trial cutting of the first spindle. , The same applies to the second spindle; when switching to the second spindle, only the spindle pointing direction needs to be marked accordingly.

[0061] Example 2 The four-station dual-rotary-table six-axis five-linkage optical grinding machine of the present invention integrates hardware and software, and includes nine motor axes: X-axis, Y-axis, Z-axis, A-axis, B-axis, C1-axis, C2-axis, S1-axis, and S2-axis. During processing, it can flexibly switch and execute different processing modes. Specifically, axis S1 is defined as the spindle motor axis that drives the first spindle 18 and the second spindle 19 to rotate about their own axis. axis S2 is defined as the spindle motor axis that drives the third spindle 20 to rotate about its own axis.

[0062] Mode 1: Dual-linkage machining mode, solving the limitations of machining complex surface shapes.

[0063] Cradle turntable linkage method (A-axis + C1 axis): such as Figures 7 to 10 As shown, a linkage method is adopted, which coordinates the swing of the A-axis cradle component with the rotation of the C1-axis turntable, that is, the five motion axes of X-axis, Y-axis, Z-axis, A-axis and C1-axis (or C2-axis) are linked for control. In this method, the B-axis rotating component remains locked and fixed, and the posture of the multi-spindle machining mechanism remains unchanged; the workpiece is mounted on the first air-bearing turntable 26 of the C1-axis turntable and is driven by the C1-axis to rotate continuously around the vertical direction (Z-axis direction); at the same time, the A-axis drives the cradle frame 23 to swing back and forth around the horizontal direction (X-axis direction), changing the spatial posture of the workpiece in real time; in conjunction with the translational feed of the three linear axes X-axis, Y-axis, and Z-axis along the horizontal front-back, horizontal left-right and vertical directions, the grinding wheel is kept in the optimal grinding posture relative to the workpiece surface at all times.

[0064] This linkage method is suitable for complex curved surface parts that are rotationally symmetric or approximately rotationally symmetric. Specifically, through the linkage of the A-axis and the C1-axis (or C2-axis), each machining point on the workpiece surface can obtain a continuously changing normal direction in the spatial coordinate system. The grinding wheel always grinds along the normal direction of the workpiece surface, thus ensuring surface accuracy. This mode can be used for high-precision machining of spherical workpieces 30 (such as...). Figure 7 As shown), aspherical workpiece 31 (e.g.) Figure 8 As shown), freeform surface workpiece 32 (such as...) Figure 9 (as shown) and hemispherical harmonic oscillator 33 (as shown) Figure 10 (As shown) is an isoplanar shape.

[0065] In this method, different spindle positions can be selected according to the processing steps. In the rough grinding stage, the first spindle 18 is equipped with a rough grinding cup-shaped grinding wheel to remove large allowances. In the semi-fine grinding or planar feature processing stage, the third spindle 20 is equipped with a disc-shaped grinding wheel to complete the processing with the circumferential surface as the working surface. In the fine grinding stage, the second spindle 19 is equipped with a fine grinding cup-shaped grinding wheel to complete the final shaping.

[0066] Rotary head table linkage method (B-axis + C1-axis): such as Figures 11 to 14 As shown, this method employs a linkage mechanism that combines B-axis oscillation with C1-axis (or C2-axis) rotation, i.e., the three linear axes X, Y, and Z with the five motion axes B and C1 achieve linkage control. In this mode, the A-axis cradle component remains horizontally locked and fixed, and the A-axis does not participate in the oscillation; the workpiece is mounted on the first air-bearing turntable 26 of the C1-axis turntable, driven by the C1-axis to rotate continuously around the vertical direction (Z-axis direction); simultaneously, the B-axis rotating component drives the entire multi-spindle machining mechanism to oscillate back and forth around the horizontal direction (Y-axis direction), changing the angle between the grinding wheel axis and the normal to the workpiece surface in real time; in conjunction with the translational feed of the three linear axes X, Y, and Z, the grinding wheel grinds the workpiece surface.

[0067] This linkage method is suitable for non-rotationally symmetric complex curved surfaces and thin-walled irregular parts that require high swing angle accuracy and response speed. This method can be used to process spherical workpieces 30 (such as...). Figure 11 As shown), aspherical workpiece 31 (e.g.) Figure 12 (as shown) and freeform surface workpiece 32 (as shown) Figure 13 (As shown).

[0068] When machining is performed using the disc-shaped grinding wheel mounted on the third spindle 20, such as Figure 14 As shown, this method is particularly suitable for grinding high-precision planar or near-planar optical components such as X-ray mirrors 34. The large-diameter end face of the disc grinding wheel forms line contact with the workpiece surface. By adjusting the grinding wheel posture with a slight oscillation on the B-axis and the workpiece rotation on the C1-axis, a high-precision plane or specific contour can be formed on the workpiece surface, while achieving high material removal efficiency and good surface quality.

[0069] During the aforementioned linkage processing, when the C1 axis (or C2 axis) participates in the linkage processing of optical components, the idle C2 axis (or C1 axis) on the other side can be used simultaneously as the dressing axis of the grinding wheel tool, without interfering with each other, thus achieving efficient collaboration of multiple axes in one integrated manner.

[0070] Mode 2: Multi-station full-process machining mode, solving the problem of repeated clamping errors.

[0071] like Figures 15 to 18 As shown, the optical element to be processed (such as aspherical workpiece 31) is clamped and fixed on the first air-bearing turntable 26 of the C1 axis turntable in one go by a vacuum chuck or mechanical clamp, and no secondary clamping is required in the entire cycle of rough grinding, fine grinding and measurement.

[0072] Rough grinding station: Control the B axis to rotate the multi-spindle machining mechanism to the initial angle (0°), so that the first spindle 18 is aligned with the workpiece, start the rough grinding cup-shaped grinding wheel installed on the first spindle 18, and the A axis, C1 axis, X axis, Y axis and Z axis perform five-axis linkage grinding according to the rough grinding machining program to perform large-mass rough grinding machining on the non-spherical workpiece 31.

[0073] Semi-finish grinding / surface grinding station: After rough grinding, the B-axis is controlled to rotate the multi-spindle machining mechanism by 90°, activating the vertically arranged third spindle 20 (equipped with a disc grinding wheel or a specific grinding head) to perform semi-finish grinding on the workpiece. The specific machining process is as follows: Figure 16 As shown.

[0074] Fine grinding station: After semi-fine grinding, control the B-axis to rotate the multi-spindle machining mechanism by 90° to 180°, so that the second spindle 19, facing the opposite direction, is aligned with the workpiece. Start the fine grinding cup-shaped grinding wheel mounted on the second spindle 19, call the fine grinding program, and finely grind the workpiece surface to achieve the final surface shape accuracy and surface roughness requirements. Specific processing steps are as follows: Figure 17 As shown.

[0075] In-situ measurement station: After fine grinding, the multi-spindle machining mechanism is further rotated to 270°, aligning the probe 21 with the workpiece surface, controlling the Z-axis downward feed, and using the probe 21 to perform precise in-situ measurement of the surface shape accuracy and three-dimensional dimensions of the aspherical workpiece 31. The specific machining process is as follows: Figure 18 As shown.

[0076] During the processing at each of the above stations, if the grinding wheel becomes dull, the dressing tool 35 on the C2 axis can be switched and adjusted via the dual rotary table to perform in-situ dressing of the grinding wheel on the first spindle 18 or the second spindle 19. The specific processing form is as follows: Figure 15 As shown.

[0077] The entire machine tool is also covered by an outer shell 1. An observation window 2 is provided in front of the outer shell 1, and a grinding fluid recovery channel 3 is provided at the bottom left side. After processing, the grinding fluid is discharged from the bottom of the machine tool base 5 through the grinding fluid recovery channel 3 into the fine filter water tank 4 for sedimentation and filtration, so as to achieve recycling.

[0078] In this embodiment, the first spindle 18 and the second spindle 19 are respectively equipped with a coarse grinding wheel and a fine grinding wheel. In other embodiments, the first spindle 18 and the second spindle 19 may also be equipped with grinding wheels of different grit sizes or shapes, or one of them may be equipped with a polishing tool. In addition to mounting a disc grinding wheel, the third spindle 20 may also be equipped with a milling cutter or a drill bit for auxiliary machining of optical components. The probe 21 may also be replaced with a laser displacement sensor or a white light interferometer probe to achieve non-contact in-situ measurement.

[0079] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0080] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0081] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. When a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intervening component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intervening component.

[0082] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0083] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A four-station, double-rotary-table, six-axis, five-linkage optical grinding machine, characterized in that, include: Machine tool base (5), and a three-axis moving assembly and a double rotary table assembly mounted on the machine tool base (5); The output end of the three-axis moving component is connected to a multi-spindle machining mechanism via a B-axis rotating component. The multi-spindle machining mechanism is provided with four machining stations, each including three machining ends and one detection end. The axis position of the B-axis rotating component is set within the range of the center of gravity variation of the multi-spindle machining mechanism. The dual rotary table component includes an A-axis cradle component mounted on the machine tool base (5), and a C1-axis rotary table and a C2-axis rotary table connected to the output end of the A-axis cradle component. The C1-axis rotary table and the C2-axis rotary table are respectively used to carry the workpiece and install the trimming tool. The axes of the three-axis moving assembly, the A-axis of the A-axis cradle component, the B-axis of the B-axis rotating component, and the C1-axis of the C1-axis turntable work together to complete different processes or in-situ measurements.

2. The four-station double rotary table six-axis five-linkage optical grinding machine tool according to claim 1, characterized in that, The three-axis moving assembly includes a Y-axis moving component mounted on the machine tool base (5), an X-axis moving component mounted on the Y-axis moving component, and a Z-axis moving component mounted on the X-axis moving component; the B-axis rotating component is mounted on the Z-axis moving component.

3. The four-station double rotary table six-axis five-linkage optical grinding machine tool according to claim 2, characterized in that, The Y-axis moving component includes a Y-axis slide rail (7) mounted on the machine tool base (5) along the Y-axis direction and a Y-axis slide block (8) slidably disposed on the Y-axis slide rail (7). The X-axis moving component includes an X-axis slide rail (10) mounted on the Y-axis slide (8) along the X-axis direction and an X-axis slide (11) slidably disposed on the X-axis slide rail (10). The Z-axis moving component includes a Z-axis slide rail (13) mounted on the X-axis slide (11) along the Z-axis direction and a Z-axis slide (14) slidably disposed on the Z-axis slide rail (13); the B-axis rotating component is disposed on the Z-axis slide (14).

4. The four-station double rotary table six-axis five-linkage optical grinding machine tool according to claim 3, characterized in that, The multi-spindle machining mechanism includes a mounting frame (15), a spindle base mounted on the mounting frame (15), a multi-station grinding spindle mounted on the spindle base, and a probe (21) fixedly mounted on the side of the mounting frame (15). The multi-station grinding spindle includes a first spindle (18), a second spindle (19), and a third spindle (20); the first spindle (18) and the second spindle (19) are coaxial and opposite in direction, and the coaxial axis of the first spindle (18) and the second spindle (19) is perpendicular to the moving direction of the Y-axis moving component; the axis of the third spindle (20) is perpendicular to the axes of the first spindle (18) and the second spindle (19), and the axial direction of the third spindle (20) is parallel to the moving direction of the Y-axis moving component.

5. A four-station, double-rotary-table, six-axis, five-linkage optical grinding machine tool according to claim 4, characterized in that, The spindle base specifically includes a first base (16) and a second base (17); the first spindle (18) and the second spindle (19) are coaxially mounted on the first base (16) in opposite directions; The second base (17) is fixedly installed on one side of the mounting surface of the first base (16), and the third spindle (20) is installed on the second base (17); the probe (21) is installed on the other side of the mounting surface of the first base (16) which is opposite to the third spindle (20).

6. The four-station double rotary table six-axis five-linkage optical grinding machine tool according to claim 1, characterized in that, The A-axis cradle assembly includes a cradle frame (23), an A-axis support base (29), and a tool setter (28); the cradle frame (23) is swayably mounted on the A-axis support base (29); the tool setter (28) is mounted on the cradle frame (23); and the A-axis support base (29) is mounted on the machine tool base (5).

7. A four-station, double-rotary-table, six-axis, five-linkage optical grinding machine tool according to claim 6, characterized in that, The C1 axis turntable is located at the center of the cradle frame (23). The C1 axis turntable includes a C1 axis base (24) mounted on the cradle frame (23) and a first air-bearing turntable (26) mounted on the C1 axis base (24). The C2 axis turntable is mounted on the cradle frame (23) and located on one side of the C1 axis turntable; the C2 axis turntable includes a C2 axis base (25) mounted on the cradle frame (23) and a second air-bearing turntable (27) mounted on the C2 axis base (25).

8. A machining method based on the four-station dual-rotary-table six-axis five-linkage optical grinding machine tool according to any one of claims 1 to 7, characterized in that, Includes the following steps: Before machining the workpiece, the axis position of the B-axis rotating component is set within the range of the center of gravity variation of the multi-spindle machining mechanism; then, the structural dimensional error between the B-axis axis and the first and second spindles is compensated by trial cutting the workpiece. After compensation, the workpiece to be processed is mounted on the C1 axis rotary table; The three-axis moving assembly can achieve five-axis linkage with the A-axis on the A-axis cradle component and the C1-axis on the C1-axis turntable; or, the three-axis moving assembly can achieve five-axis linkage with the B-axis on the B-axis rotating component and the C1-axis on the C1-axis turntable, thereby controlling the multi-spindle machining mechanism to perform rough grinding, semi-fine grinding, and fine grinding on the workpiece. During the machining process, different processes or in-situ measurements are completed by rotating the multi-spindle machining mechanism; The dressing tool mounted on the C2 axis rotary table is used to dress the grinding wheel on the multi-spindle machining mechanism in place.

9. The processing method of the four-station double rotary table six-axis five-linkage optical grinding machine tool according to claim 8, characterized in that, The axis position of the B-axis rotating component is set within the range of the center of gravity variation of the multi-spindle machining mechanism, specifically: Establish the center of gravity of the multi-spindle machining mechanism using the origin of any coordinate system as a reference. , , The expression for ) is as follows: in, To ensure the quality of multi-spindle machining mechanisms without installing any grinding wheels, The mass of the grinding wheel mounted on the first spindle. The mass of the grinding wheel mounted on the second spindle. The mass of the grinding wheel mounted on the third spindle; The coordinates of the center of gravity of the multi-spindle machining mechanism under no-load conditions; The coordinates of the center of gravity of the grinding wheel mounted on the first spindle are ( ( ) represents the coordinates of the center of gravity of the grinding wheel mounted on the second spindle; () represents the coordinates of the center of gravity of the grinding wheel mounted on the third spindle; Based on the expression for the center of gravity of the multi-spindle machining mechanism, the overall center of gravity coordinates of the multi-spindle machining mechanism under different grinding wheel load combinations are calculated to obtain the range of center of gravity variation of the multi-spindle machining mechanism. The axis position of the B-axis rotating component is set within the center of gravity variation range of the multi-spindle machining mechanism.

10. The processing method of the four-station double rotary table six-axis five-linkage optical grinding machine tool according to claim 9, characterized in that, The structural dimensional errors between the B-axis and the first and second spindles are compensated by trial cutting of the workpiece. Specifically: Move the multi-spindle machining mechanism above the test-cut workpiece, so that the center of the multi-spindle machining mechanism is at the theoretical distance above the workpiece surface. At this point, due to the actual structural dimensions between the B-axis axis and the first spindle end face... Manufacturing and assembly errors exist, resulting in vertical structural dimensional errors. ; Structural dimensional error in the vertical direction Obtain the actual structural dimensions in the vertical direction. Actual structural dimensions in the horizontal direction Specifically: By oscillating only the B-axis, the grinding wheel is machined into a spherical surface on the test-cut workpiece, and the actual radius of the sphere is measured. When machining a spherical surface, with the B-axis as the center of rotation, the sum of the distance from the B-axis to the center of the arc of the grinding wheel and the radius of the arc of the grinding wheel should equal the actual radius of the spherical surface being machined. The specific expression is as follows: Among them, the actual structural dimensions in the vertical direction The specific expression is: Obtain the actual structural dimensions in the horizontal direction The specific expression is: In the formula: This refers to the actual dimension in the x-direction between the B-axis and the first main axis, which is the actual structural dimension in the horizontal direction. This is the actual dimension in the z-direction between the B-axis axis and the end face of the first spindle. The actual radius of the sphere obtained from the trial cut of the workpiece. The median diameter of the grinding wheel. Where is the radius of the arc of the grinding wheel. The height of the grinding wheel; This is the theoretical dimension in the z-direction between the B-axis axis and the end face of the first spindle. Based on the actual structural dimensions in the vertical direction Actual structural dimensions in the horizontal direction This enables compensation for structural dimensional errors between the B-axis and the first and second main axes.

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