Composite polishing machine tool and polishing method thereof

Abstract

The invention discloses a composite polishing machine tool and a polishing method thereof. The composite polishing machine tool comprises a base, a transmission mechanism, a working shaft, a finishing shaft and a rotary table. The transmission mechanism is arranged on the base; the working shaft is arranged on the transmission mechanism; a clamping assembly capable of rotating in the Z direction is arranged on the working shaft. The finishing shaft is arranged on the transmission mechanism and provided with a milling cutter, a turning tool and a grinding head capable of rotating around the Z-direction axis. The rotary table is arranged on the base and comprises a base, a rotating mechanism, a heating table and a polishing disc. The rotating mechanism is arranged on the base, the heating table is arranged on the rotating mechanism, the rotating mechanism drives the heating table to rotate around the Z-direction axis, the heating table is connected with a heating assembly, the polishing disc is arranged at the top of the heating table, the heating assembly is used for heating the polishing disc, and a polishing pad is arranged at the top of the polishing disc and used for making contact with the polished surface of a workpiece. The machine tool integrates the functions of polishing machining, polishing pad finishing and temperature control deformation compensation, the surface shape precision of a workpiece is effectively improved, and the machining requirement of ultra-precision polishing is met.

Description

Technical Field

[0001] This invention relates to the field of polishing machine tool technology, and in particular to a composite polishing machine tool and its polishing method. Background Technology

[0002] Chemical mechanical polishing (CMP) is a key process for achieving global planarization in ultra-precision machining fields such as optical components and semiconductor wafers. Its working principle involves placing the workpiece (e.g., an optical component) on the surface of a polishing pad, and then introducing a polishing slurry into the pad. A polishing interface is formed between the workpiece surface, the polishing slurry, and the surface of the polishing pad. Within this interface, these three elements interact. First, the chemical action of the polishing slurry softens the workpiece surface. Then, the mechanical cutting action of the polishing particles in the slurry against the softened surface achieves efficient and uniform material removal.

[0003] In CMP polishing, the polishing interface state between the polishing pad and the workpiece surface directly determines the polishing quality, and the surface morphology of the polishing pad (including macroscopic flatness and microscopic groove structure) is the core factor affecting the interface state. An ideal polishing pad surface morphology should ensure uniform distribution of the polishing slurry, provide stable mechanical action, and maintain morphological consistency throughout the polishing process.

[0004] However, in existing CMP equipment and processes, the surface morphology of the polishing pad is adjusted solely through trimming techniques, which cannot meet the stringent requirements of current ultra-precision machining for the surface accuracy of optical components. Traditionally, the surface morphology of the polishing pad is primarily achieved through pre-treatment trimming, i.e., the polishing pad is pre-treated with a dedicated trimming tool before machining, resulting in the trimming process being independent of the polishing process. When the machining process detects that the workpiece accuracy does not meet the requirements, only limited parameters such as the workpiece polishing pressure and placement can be quickly adjusted. It is impossible to actively and in real-time control the surface morphology of the polishing pad during the polishing process. Yet, the surface morphology of the polishing pad is a crucial parameter determining the surface machining quality of the workpiece, and this technological limitation restricts further improvements in the surface accuracy of the workpiece.

[0005] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a composite polishing machine tool and its polishing method, which aims to solve the technical problem that the chemical mechanical polishing technology in the prior art cannot control the surface morphology of the polishing pad in real time.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A composite polishing machine tool, comprising: Base; The transmission mechanism is mounted on the base; The working shaft is mounted on the transmission mechanism, which drives the working shaft to translate along the X direction and / or move up and down along the Z direction; the working shaft is equipped with a clamping assembly that can rotate around the Z direction, and the clamping assembly is used to clamp the workpiece. A dressing shaft is mounted on a transmission mechanism. The transmission mechanism drives the dressing shaft to translate along the X direction and / or move up and down along the Z direction. The dressing shaft is equipped with a milling cutter, a turning tool, and a grinding head that can rotate around the Z-axis. A turntable is mounted on a base. The turntable includes a base, a rotating mechanism, a heating table, and a polishing disc. The rotating mechanism is mounted on the base, and the heating table is mounted on the rotating mechanism. The rotating mechanism drives the heating table to rotate around the Z-axis. The heating table is connected to a heating component. The polishing disc is mounted on top of the heating table. The heating component is used to heat the polishing disc. A polishing pad is provided on top of the polishing disc. The polishing pad is used to contact the polishing surface of the workpiece.

[0008] Furthermore, the heating assembly includes a variable frequency water chiller, a pressure regulating valve, an inlet pipe, and an outlet pipe. The heating platform has a vortex-shaped flow channel groove on the side facing the polishing disc. The outlet end of the variable frequency water chiller, the pressure regulating valve, the inlet pipe, and the inlet end of the flow channel groove are connected in sequence. The outlet end of the flow channel groove, the outlet pipe, and the inlet end of the variable frequency water chiller are connected in sequence.

[0009] Furthermore, the polishing disc includes at least one connecting platform, which is stacked sequentially along the Z-direction and fixed on the top of the heating platform, and the coefficients of thermal expansion of each connecting platform are different.

[0010] Furthermore, the rotating mechanism includes a first drive motor, a first rotating shaft, a support member, and a gas static pressure bearing. The first drive motor is mounted on the base, and the output end of the first drive motor is connected to the first rotating shaft for transmission. The cross-section of the first rotating shaft is I-shaped. The support member is mounted on the base and sleeved on the outer circumference of the first rotating shaft. The first rotating shaft is rotatably connected to the support member through the gas static pressure bearing.

[0011] Furthermore, the gas static pressure bearing includes a first planar throttling assembly, a second planar throttling assembly, and a first radial throttling device; the first rotating shaft includes an upper static pressure plate, a spindle, and a lower static pressure plate that are fixedly connected in sequence. The first radial throttle is installed between the outer peripheral surface of the spindle and the inner wall of the support member. The support member has a first through hole for introducing compressed gas into the first radial throttle. The upper end face of the support member is provided with at least one first annular groove, the first planar throttling component includes several first planar throttling devices arranged in a circumferential array and embedded in the first annular groove, and the support member is provided with several second through holes corresponding one-to-one with the first planar throttling devices. The lower end face of the support member is provided with at least one second annular groove, the second planar throttling component includes several second planar throttling devices arranged in a circumferential array and embedded in the second annular groove, and the support member is provided with several third through holes corresponding one-to-one with the second planar throttling devices.

[0012] Furthermore, the clamping assembly includes a fixed disk and a plurality of movable jaws arranged in a circumferential array on the fixed disk. Each movable jaw is provided with a plurality of abutment blocks for abutting against the outer peripheral surface of the workpiece.

[0013] Furthermore, the trimming shaft includes a first base plate, a first housing, a Y-axis angle adjustment mechanism, an X-axis angle adjustment mechanism, a first shaft seat, and a trimming main shaft; The first housing is rotatably connected to the first substrate around the Y-axis; the Y-axis angle adjustment mechanism includes a first adjustment component and a first fastening component. The first adjustment component is disposed on the first substrate and is used to drive the first housing to rotate relative to the first substrate around the Y-axis; the first fastening component is disposed between the first substrate and the first housing and is used to lock the first housing to the first substrate. The first bearing seat is housed in the first housing and is rotatably connected to the first housing about the X-axis; the X-axis angle adjustment mechanism includes a second adjustment component and a second fastening component. The second adjustment component is disposed on the first housing and is used to drive the first bearing seat to rotate relative to the first housing about the X-axis; the second fastening component is disposed on the first housing and is used to lock the first bearing seat in the first housing. The dressing spindle is rotatably connected to the first bearing along the Z-axis. The top of the first bearing is connected to a second drive motor, which is connected to the upper end of the dressing spindle. The milling cutter and turning tool are fixed at the bottom of the first housing; the grinding head is fixed at the lower end of the dressing spindle.

[0014] Furthermore, the upper part of the first housing is rotatably connected to the first substrate. The first adjustment assembly includes at least one first adjustment screw and at least one second adjustment screw. The first adjustment screw and the second adjustment screw are symmetrically arranged on both sides of the first substrate, and their axes are parallel to the X-direction. The ends of the first adjustment screw and the second adjustment screw abut against the bottom of both sides of the first housing. The first fastening assembly includes a plurality of fastening screws. The first housing is provided with a plurality of mounting holes parallel to the Y-direction. The inner diameter of the mounting holes is larger than the outer diameter of the fastening screws. Each fastening screw passes through the corresponding mounting hole and is threadedly connected to the first substrate.

[0015] Furthermore, the X-axis angle adjustment mechanism also includes two second rotating shafts parallel to the X-axis, which are symmetrically arranged on both sides of the first housing. The two second rotating shafts are rotatably engaged with the first bearing seat respectively. The second adjustment assembly includes several third and fourth adjusting screws parallel to the Y-axis. The third adjusting screws are screwed to the first housing and their ends abut against the upper part of the first bearing seat. The fourth adjusting screws are screwed to the first housing and their ends abut against the lower part of the first bearing seat. The second fastening assembly includes several abutting screws parallel to the X-axis, which are symmetrically arranged on both sides of the first housing and their ends abut against the side wall of the first bearing seat.

[0016] A polishing method for a composite polishing machine tool, applied to the composite polishing machine tool, the polishing method comprising: Trim and groove the polishing pad; Clamp the workpiece onto the clamping assembly of the working shaft, with the polished surface of the workpiece facing the polishing pad, and place a counterweight on the side of the workpiece away from the polishing pad. Polishing liquid is dripped onto the surface of the polishing pad; the working shaft drives the workpiece to rotate at a first preset speed, and the rotating mechanism drives the polishing pad to rotate in the opposite direction at a second preset speed; At least three different temperature values ​​are preset, and the variable frequency water chiller is controlled to adjust the circulating water to the corresponding temperature and introduce it into the flow channel groove; after the first preset polishing time, the first surface shape accuracy of the workpiece polishing surface is detected and recorded. Comparing all the first surface accuracy, the two temperature values ​​with the best surface accuracy are selected as the temperature peak and temperature valley values ​​of the thermal fluid temperature field, respectively. At least three different pressure values ​​are preset, and the pressure regulating valve is controlled to introduce hot fluid into the flow channel groove at the corresponding pressure; after the second preset polishing time, the second surface shape accuracy of the workpiece polishing surface is detected and recorded. By comparing all the second surface accuracy, the two pressure values ​​with the best surface accuracy are selected and used as the pressure peak and pressure valley values ​​of the thermal fluid temperature field, respectively. At least two different types of periodic temperature-time curves are preset. The periodic temperature-time curves are defined by temperature peaks and temperature valleys. The hot fluid is controlled to flow into the flow channel groove according to the corresponding curves. After a third preset polishing time, the third surface shape accuracy is detected and recorded. The optimal curve is selected as the final temperature-time curve. At least two different types of periodic pressure-time curves are preset. The periodic pressure-time curves are defined by pressure peak and pressure valley values. The hot fluid is controlled to flow into the flow channel groove according to the corresponding curve. After a fourth preset polishing time, the fourth surface accuracy is detected and recorded. The optimal curve is selected as the final pressure-time curve. The variable frequency water chiller and pressure regulating valve are controlled to adjust the heat fluid according to the final temperature-time curve and the final pressure-time curve, respectively, until the fifth preset polishing time ends, thus completing the polishing.

[0017] Beneficial effects: This invention provides a composite polishing machine tool that integrates polishing processing, polishing pad dressing, and temperature-controlled deformation compensation functions. The overall structure is compact and highly integrated. The dressing axis integrates multiple cutting tools, enabling integrated flatness dressing and micro-grooving of the polishing pad, effectively simplifying pretreatment processes. Simultaneously, the workpiece and polishing pad can rotate in opposite directions to form stable relative frictional motion, which helps improve the uniformity of material removal from the workpiece surface. The heating component can regulate the controllable thermal deformation generated by the polishing pad, achieving active compensation for its surface morphology, ensuring that the polishing pad always maintains optimal contact with the workpiece. Through thermo- and chemical-mechanical synergistic polishing, the surface accuracy of the workpiece can be improved, fully meeting the processing requirements of ultra-precision polishing.

[0018] This invention also provides a polishing method for a composite polishing machine tool. The method first pre-treats the polishing pad to ensure uniform distribution of the polishing fluid, and then ensures the uniformity and consistency of material removal from the workpiece surface by rotating the workpiece and the polishing pad in opposite directions. Subsequently, the optimal temperature and pressure parameters and the corresponding periodic change curves are selected through experiments, and the polishing pad morphology is compensated in real time by dynamic thermofluid control, which ultimately effectively improves the surface accuracy and surface quality of the workpiece and efficiently completes ultra-precision polishing. Attached Figure Description

[0019] Figure 1 The structural diagram of the composite polishing machine tool provided by the present invention; Figure 2 This is a front sectional view of the composite polishing machine tool provided by the present invention; Figure 3 A cross-sectional view of the rotary table of the composite polishing machine tool provided by the present invention; Figure 4 Exploded view of the rotary table of the composite polishing machine tool provided by the present invention; Figure 5 This is a structural diagram of the support component in the composite polishing machine tool provided by the present invention; Figure 6 This is a structural diagram of the dressing shaft in the composite polishing machine tool provided by the present invention; Figure 7 Explosion of the dressing shaft in the composite polishing machine tool provided by the present invention Figure 1 ; Figure 8 Explosion of the dressing shaft in the composite polishing machine tool provided by the present invention Figure 2 ; Figure 9 Partial cross-section of the dressing shaft in the composite polishing machine tool provided by the present invention. Figure 1 ; Figure 10This is a schematic diagram of the connection of the first fastening component in the composite polishing machine tool provided by the present invention. Figure 11 Partial cross-section of the dressing shaft in the composite polishing machine tool provided by the present invention. Figure 2 ; Figure 12 This is a structural diagram of the working shaft in the composite polishing machine tool provided by the present invention; Figure 13 The flowchart illustrates the polishing method of the composite polishing machine tool provided by this invention.

[0020] Reference numerals: Base 1, Transmission mechanism 2, Translation assembly 21, Slide table 22, First lifting assembly 23, Second lifting assembly 24, Working shaft 3, Clamping assembly 31, Fixed plate 311, Movable gripper 312, Adjusting block 3121, Vertical rod 3122, Horizontal rod 3123, Abutting block 313, Arc-shaped abutting surface 3131, Second base plate 32, Second housing 33, Second bearing seat 34, Working spindle 35, Third drive motor 36, Dressing shaft 4, First base plate 41, First housing 4 2. Mounting hole 421, third rotating shaft 422, Y-axis angle adjustment mechanism 43, first adjustment component 431, first adjustment screw 4311, second adjustment screw 4312, first fastening component 432, X-axis angle adjustment mechanism 44, second adjustment component 441, third adjustment screw 4411, fourth adjustment screw 4412, second fastening component 442, second rotating shaft 443, first shaft seat 45, shaft hole 451, third planar throttle 452, second radial throttle 453, repair Main spindle 46, first shaft section 461, second shaft section 462, third annular groove 463, second drive motor 47, water baffle 48, protrusion 481, turntable 5, base 51, rotating mechanism 52, first drive motor 521, first rotating shaft 522, upper static pressure plate 5221, spindle 5222, lower static pressure plate 5223, support member 523, first through hole 5231, first annular groove 5232, second through hole 5233, second annular groove 5234, third through hole 5235, gas Hydrostatic bearing 524, first radial throttle 5241, first planar throttle 5242, second planar throttle 5243, vent groove 5244, insert 5245, stepped portion 5246, vent hole 5247, heating table 53, flow channel groove 531, polishing disc 54, connecting table 541, polishing pad 55, heating assembly 6, variable frequency water chiller 61, pressure regulating valve 62, water inlet pipe 63, water outlet pipe 64, two-way rotary joint 65, two-position three-way solenoid valve 66, counterweight 7, workpiece 8. Detailed Implementation

[0021] This invention provides a composite polishing machine tool and its polishing method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0022] In the description of this invention, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on the invention. Furthermore, "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means two or more.

[0023] In this invention, in the XYZ coordinate system, the X direction is defined as the horizontal movement direction of the working axis 3 and the trimming axis 4, the Y direction is the direction perpendicular to the X direction, and the Z direction is the vertical direction. By rotating the first housing 42 around the Y direction, the perpendicularity adjustment of the trimming main shaft 46 in the X0Z plane can be realized. By rotating the first bearing 45 around the X direction, the perpendicularity adjustment of the trimming main shaft 46 in the Y0Z plane can be realized, thereby achieving precise adjustment of the perpendicularity of the trimming main shaft 46 in the two-dimensional direction.

[0024] Please see Figures 1 to 12 As shown, this invention provides a composite polishing machine tool, including a base 1, a transmission mechanism 2, a working shaft 3, a dressing shaft 4, and a turntable 5; the transmission mechanism 2 is mounted on the base 1; the working shaft 3 is mounted on the transmission mechanism 2, and the transmission mechanism 2 drives the working shaft 3 to translate along the X direction and / or move up and down along the Z direction; the working shaft 3 is provided with a clamping assembly 31 that can rotate around the Z direction, and the clamping assembly 31 is used to clamp a workpiece 8; the dressing shaft 4 is mounted on the transmission mechanism 2, and the transmission mechanism 2 drives the dressing shaft 4 to translate along the X direction and / or move up and down along the Z direction, and the dressing shaft 4 is provided with a milling cutter, a turning tool, and a turning tool. A grinding head that can rotate around the Z-axis; a turntable 5 is mounted on a base 1, and the turntable 5 includes a base 51, a rotating mechanism 52, a heating table 53, and a polishing disc 54; the rotating mechanism 52 is mounted on the base 51, the heating table 53 is mounted on the rotating mechanism 52, the rotating mechanism 52 drives the heating table 53 to rotate around the Z-axis, the heating table 53 is connected to a heating component 6, the polishing disc 54 is mounted on the top of the heating table 53, the heating component 6 is used to heat the polishing disc 54, the top of the polishing disc 54 is provided with a polishing pad 55, and the polishing pad 55 is used to contact the polishing surface of the workpiece 8.

[0025] Before polishing, the dressing shaft 4 is moved above the polishing pad 55 via the transmission mechanism 2. According to the polishing process requirements, a cutting tool or grinding head on the dressing shaft 4 is selected to smooth the surface of the polishing pad 55, ensuring its macroscopic flatness. Subsequently, a milling cutter is used to mill grooves into the smoothed surface of the polishing pad 55, forming a micro-groove structure of preset specifications, providing a channel for the uniform distribution of polishing fluid and the removal of debris. The grinding head is not shown in the attached diagram.

[0026] After pretreatment, the workpiece 8 to be processed is placed on the corresponding position on the surface of the polishing pad 55, and the workpiece 8 is clamped by the clamping component 31 on the working shaft 3. A counterweight 7 of appropriate weight is placed on the upper surface of the workpiece 8 away from the polishing pad 55. The gravity of the counterweight 7 applies a stable polishing pressure to the workpiece 8 to ensure effective contact of the polishing interface. During the polishing process, polishing liquid is continuously dripped onto the surface of the polishing pad 55. The working shaft 3 drives the workpiece 8 to rotate around the Z direction. The rotation mechanism 52 of the turntable 5 drives the heating table 53, the polishing disk 54 and the polishing pad 55 to rotate in opposite directions, forming relative frictional motion. The heating component 6 adjusts the heating temperature according to the real-time processing requirements. The heat is transferred to the polishing pad 55 through the polishing disk 54, causing the polishing pad 55 to undergo controllable thermal deformation, thereby adjusting its surface morphology in real time and realizing active compensation for the macroscopic curved surface of the polishing pad 55.

[0027] With the above settings, on the one hand, the cutting tool, grinding head and milling cutter integrated in the dressing shaft 4 can complete the flatness correction and micro-grooving of the polishing pad 55; on the other hand, the heating component 6 can control the temperature of the polishing pad 55 in real time, and adjust the surface morphology of the polishing pad 55 in a timely manner according to the processing state of the workpiece 8, so as to ensure that the polishing pad 55 always maintains the optimal contact state with the workpiece 8 during the polishing process, realize the synergistic effect of thermo-chemical-mechanical, effectively improve the surface accuracy of the workpiece 8, and meet the needs of ultra-precision machining.

[0028] The composite polishing machine tool also includes a liquid supply device, which comprises a storage tank, a nozzle connected to the storage tank, and a filter bag located at the water outlet of the nozzle. The storage tank contains polishing liquid, which continuously supplies liquid to the nozzle. After being filtered by the filter bag, the polishing liquid drips onto the surface of the polishing pad 55, thereby continuously replenishing the polishing liquid on the surface of the polishing pad 55. A liquid receiving groove is provided on the base 1. The polishing liquid collects along the groove of the polishing pad 55 into the liquid receiving groove and is then discharged into the storage tank through a drain pipe, realizing the recycling of the polishing liquid. The liquid supply device is not shown in the attached drawings.

[0029] See Figure 1The transmission mechanism 2 includes a translation component 21, a slide table 22, a first lifting component 23, and a second lifting component 24. The slide table 22 is slidably connected to the base 1 along the X-direction. The translation component 21 drives the slide table 22 to reciprocate along the X-direction. The first lifting component 23 and the second lifting component 24 are both mounted on the slide table 22. The working shaft 3 and the dressing shaft 4 are slidably connected to the slide table 22 along the Z-direction. The first lifting component 23 drives the working shaft 3 to lift and lower to clamp and release the workpiece 8. The second lifting component 24 drives the dressing shaft 4 to lift and lower to adjust the installation height of the lathe tool, milling cutter, or grinding head. Both lifting components and the translation component 21 are equipped with high-precision grating rulers to achieve real-time closed-loop control of displacement feedback.

[0030] In the above, the translation component 21 adopts a servo motor driven ball screw pair transmission component, and the lifting component adopts a cylinder driven component.

[0031] Furthermore, the translation component 21 can be configured as two, with the two translation components 21 driving the working axis 3 and the trimming axis 4 to translate independently along the X direction.

[0032] In a preferred embodiment, see [reference] Figure 3 , 4 The heating assembly 6 includes a variable frequency water chiller 61, a pressure regulating valve 62, a water inlet pipe 63, and a water outlet pipe 64. The heating table 53 has a vortex-shaped flow channel groove 531 on the side facing the polishing disc 54. The water outlet end of the variable frequency water chiller 61, the pressure regulating valve 62, the water inlet pipe 63, and the water inlet end of the flow channel groove 531 are connected in sequence. The water outlet end of the flow channel groove 531, the water outlet pipe 64, and the water inlet end of the variable frequency water chiller 61 are connected in sequence to form a closed hot fluid circulation path. During the polishing operation, the variable frequency water chiller 61 adjusts the circulating water to the preset temperature according to the real-time temperature requirements of the polishing process, and regulates the circulating water pressure through the pressure regulating valve 62. The temperature- and pressure-regulated circulating water is then transported to the vortex-shaped flow channel 531 of the heating table 53 through the inlet pipe 63. As the circulating water flows through the flow channel 531, it evenly transfers heat to the polishing disc 54, and then the polishing disc 54 conducts heat to the polishing pad 55, thus achieving precise temperature control of the polishing pad 55. After heat exchange with the heating table 53, the circulating water flows back to the variable frequency water chiller 61 through the outlet end of the flow channel 531 and the outlet pipe 64, realizing the recycling and re-temperature adjustment of the circulating water, and continuously providing a stable heat source for the temperature control of the polishing pad 55.

[0033] During the actual polishing process, the variable frequency water chiller 61 continuously introduces a hot fluid with periodically fluctuating temperature and pressure into the flow channel 531, forming a dynamic hot fluid field within the heating stage 53. This dynamic hot fluid field induces the polishing disc 54 to undergo dynamic elastic deformation. The polishing pad 55, being attached to the surface of the polishing disc 54, deforms synchronously with the polishing disc 54. This dynamic deformation allows each point on the polishing surface of the workpiece 8 to traverse a larger area of ​​the polishing pad 55 surface, effectively improving the uniformity of material removal at each point on the polishing surface of the workpiece 8, thereby achieving high-precision processing of the workpiece 8.

[0034] Specifically, the heating assembly 6 further includes a two-way rotary joint 65, which is located at the bottom of the base 51. The two inlets of the two-way rotary joint 65 are respectively connected to the inlet pipe 63 and the outlet pipe 64, and its two outlets are respectively connected to the inlet end and outlet end of the flow channel 531. The two-way rotary joint 65 adapts to the rotation requirements of the heating platform 53, preventing the inlet pipe 63 and the outlet pipe 64 from becoming entangled during the rotation of the heating platform 53.

[0035] To achieve the switching of the flow direction of the hot fluid in the flow channel 531 within the heating plate, the heating assembly 6 is also equipped with a two-position three-way solenoid valve 66. The two-position three-way solenoid valve 66 is installed between the pressure regulating valve 62 and the water inlet pipe 63, as well as between the water inlet end and the water outlet pipe 64 of the variable frequency water chiller 61. By switching the valve core position of the two-position three-way solenoid valve 66, the flow direction of the hot fluid in the flow channel 531 can be changed, so that the heat flows clockwise or counterclockwise along the vortex linear flow channel.

[0036] In another embodiment, the heating component 6 can be replaced by an electric heating wire instead of the aforementioned water circulation heating system. The electric heating wire is embedded in the heating platform 53 in a spiral structure. By adjusting the input power of the electric heating wire, precise temperature control of the heating platform 53 can be achieved, thereby uniformly transferring heat to the polishing disc 54 and the polishing pad 55 through the heating platform 53, meeting the temperature control requirements of the polishing pad 55.

[0037] In a preferred embodiment, see [reference] Figure 3 The polishing pad 54 includes at least one connecting platform 541, which is stacked sequentially along the Z-direction and fixed on the top of the heating platform 53. The coefficients of thermal expansion of each connecting platform 541 are different. When the heat transferred by the heating platform 53 acts on each connecting platform 541, the connecting platforms 541 with different coefficients of thermal expansion will undergo differentiated thermal deformation due to heating. The deformations of each connecting platform 541 are superimposed and work synergistically to cause dynamic changes on the surface of the polishing pad 55.

[0038] The connecting platform 541 can be made of heat-conducting materials such as gray cast iron and aluminum alloy. The polishing disc 54 can be set as a single-level single-material connecting platform 541, a multi-layer connecting platform 541 of different materials stacked structure, or a partitioned connecting platform 541 of different materials combined structure, depending on the polishing process requirements.

[0039] In a preferred embodiment, see [reference] Figure 3 , 4 The rotating mechanism 52 includes a first drive motor 521, a first rotating shaft 522, a support member 523, and a gas static pressure bearing 524. The first drive motor 521 is mounted on the base 51, and its output end is connected to the first rotating shaft 522. The first rotating shaft 522 has an I-shaped cross-section. The support member 523 is mounted on the base 51 and sleeved around the outer circumference of the first rotating shaft 522. The first rotating shaft 522 is rotatably connected to the support member 523 via the gas static pressure bearing 524. Specifically, the first drive motor 521 is a torque motor, with its stator fixed on the base 51 and its rotor connected to the first rotating shaft 522. During the polishing operation, the first drive motor 521 drives the first rotating shaft 522 to rotate. During the rotation of the first rotating shaft 522, a non-contact rotational fit is formed between the gas hydrostatic bearing 524 and the support member 523. The support member 523 provides stable radial and axial support for the first rotating shaft 522. At the same time, the I-shaped structure of the first rotating shaft 522 can effectively improve its own rotational rigidity and stability, and reduce deformation and shaking under high-speed rotation. The first rotating shaft 522 synchronously drives the top heating table 53, polishing disc 54 and polishing pad 55 to rotate smoothly around the Z-axis, so as to achieve uniform polishing of the polishing surface of the workpiece 8.

[0040] Further, see Figure 3 , 4 5. The gas static pressure bearing 524 includes a first planar throttling assembly, a second planar throttling assembly, and a first radial throttling device 5241; the first rotating shaft 522 includes an upper static pressure plate 5221, a spindle 5222, and a lower static pressure plate 5223 that are fixedly connected in sequence, with the spindle 5222 disposed between the upper static pressure plate 5221 and the lower static pressure plate 5223, forming an I-shaped integral structure.

[0041] The first radial throttle 5241 is installed between the outer peripheral surface of the spindle 5222 and the inner wall of the support member 523. The support member 523 has a first through hole 5231 for introducing compressed gas into the first radial throttle 5241, thereby realizing radial air float support between the spindle 5222 and the support member 523. Specifically, the outer peripheral surface of the first radial throttle 5241 has a plurality of interconnected venting grooves 5244. The first through hole 5231 is connected to one of its venting grooves 5244, which can uniformly introduce compressed gas into each venting groove 5244 to form a stable radial air film, thereby realizing radial air float support between the spindle 5222 and the support member 523.

[0042] The upper end face of the support member 523 is provided with at least one first annular groove 5232. The first planar throttling component includes several first planar throttling devices 5242 arranged in a circumferential array and embedded in the first annular groove 5232. The support member 523 is provided with several second through holes 5233 corresponding one-to-one with the first planar throttling devices 5242. In this embodiment, there are two first annular grooves 5232. Eight first planar throttling devices 5242 are embedded in each first annular groove 5232. Adjacent first planar throttling devices 5242 are fixed by inserts 5245. The first planar throttling devices 5242 in the two first annular grooves 5232 are staggered to optimize the uniformity and load-bearing capacity of the axial air film. Specifically, each first planar throttle 5242 includes a stepped portion 5246 located at its edge and a plurality of vent holes 5247 opened inside it. One end of each of the plurality of vent holes 5247 is connected to the stepped portion 5246, and the stepped portion 5246 is connected to the second through hole 5233, which can uniformly introduce compressed gas into each vent hole 5247, thereby forming a stable axial air film and realizing axial air float support between the support member 523 and the upper static pressure plate 5221.

[0043] The lower end face of the support member 523 is provided with at least one second annular groove 5234. The second planar throttling assembly includes several second planar throttling devices 5243 arranged in a circumferential array and embedded in the second annular groove 5234. The support member 523 is provided with several third through holes 5235 corresponding one-to-one with the second planar throttling devices 5243. In this embodiment, since the surface area of ​​the lower static pressure plate 5223 is smaller than that of the upper static pressure plate 5221, only one second annular groove 5234 is provided. Eight second planar throttling devices 5243 are embedded in the second annular groove 5234. The second planar throttling devices 5243 have the same structure as the first planar throttling device 5242 and can also uniformly distribute the compressed gas introduced, thereby forming an axial air film and realizing axial air float support between the support member 523 and the lower static pressure plate 5223.

[0044] In practical applications, the compressed gas pressure supplied to each of the first planar throttle valves 5242 and the second planar throttle valve 5243 can be independently controlled to achieve differentiated regulation of the axial air film bearing capacity. Specifically, the compressed gas pressure supplied to the first planar throttle valve 5242 located below the workpiece 8 can be increased, and the upward bearing capacity generated by the high-pressure axial air film can be used to directly balance the gravitational load of the workpiece 8, so that the first rotating shaft 522 maintains axial force balance. Compared with the existing technology that requires additional counterweights to be placed diagonally between the polishing pad 54 and the workpiece 8 to balance the force on the rotating shaft, this structure can achieve force self-balancing by independently adjusting the axial air buoyancy pressure, without the need to add counterweights, and effectively reduces abnormal wear of the polishing pad 55 and the counterweights, extending their service life.

[0045] In another embodiment, the rotational connection structure between the base 51 and the first rotating shaft 522 can be replaced by bearing structures such as mechanical bearings and hydrostatic bearings, in addition to the planar throttle and radial throttle mentioned above.

[0046] In a preferred embodiment, see [reference] Figure 12 The clamping assembly 31 includes a fixed disk 311 and a plurality of movable grippers 312 arranged in a circumferential array on the fixed disk 311. Each movable gripper 312 is provided with a plurality of abutment blocks 313, which are used to abut against the outer peripheral surface of the workpiece 8. The plurality of abutment blocks 313 cooperate with each other to limit the placement position of the workpiece 8, ensuring that the central axis of the workpiece 8 remains coaxial with the axis of the working shaft 3. The working shaft 3 drives the clamping assembly 31 to rotate around the Z-axis, thereby causing the workpiece 8 to rotate synchronously.

[0047] Specifically, four movable grippers 312 are provided. Each movable gripper 312 includes an adjusting block 3121 radially slidably connected to the fixed disk 311, a vertical rod 3122 perpendicularly connected to the adjusting block 3121, and a horizontal rod 3123 perpendicularly connected to the vertical rod 3122. The adjusting block 3121 and the horizontal rod 3123 are perpendicular to each other. At least two abutting blocks 313 are adjustable along the length of the horizontal rod 3123 to accommodate workpieces 8 of different diameters. Preferably, the abutting block 313 has an arc-shaped abutting surface 3131, which abuts against the outer peripheral surface of the workpiece 8 to form a line-surface contact engagement. Through the cooperation of multiple movable grippers 312, the placement position of the workpiece 8 can be further precisely defined.

[0048] In a preferred embodiment, see [reference] Figure 6-11The trimming shaft 4 includes a first base plate 41, a first housing 42, a Y-axis angle adjustment mechanism 43, an X-axis angle adjustment mechanism 44, a first bearing seat 45, and a trimming main shaft 46. The first base plate 41 is slidably connected to the slide table 22 along the Z-axis. The first housing 42 is rotatably connected to the first base plate 41 about the Y-axis. The Y-axis angle adjustment mechanism 43 includes a first adjustment component 431 and a first fastening component 432. The first adjustment component 431 is disposed on the first base plate 41 and is used to drive the first housing 42 to rotate relative to the first base plate 41 about the Y-axis. The first fastening component 432 is disposed between the first base plate 41 and the first housing 42 and is used to lock the first housing 42 to the first base plate 41. The first bearing seat 45 is accommodated in the first housing. The first housing 42 is rotatably connected to the first housing 42 about the X-axis. The X-axis angle adjustment mechanism 44 includes a second adjustment component 441 and a second fastening component 442. The second adjustment component 441 is disposed on the first housing 42 and is used to drive the first bearing seat 45 to rotate relative to the first housing 42 about the X-axis. The second fastening component 442 is disposed on the first housing 42 and is used to lock the first bearing seat 45 to the first housing 42. The dressing spindle 46 is rotatably connected to the first bearing seat 45 along the Z-axis. The top of the first bearing seat 45 is connected to a second drive motor 47, and the second drive motor 47 is drivenly connected to the upper end of the dressing spindle 46. The milling cutter and the turning tool are respectively fixed at the bottom of the first housing 42. The grinding head is fixed at the lower end of the dressing spindle 46.

[0049] By adjusting the perpendicularity of the dressing spindle 46 in a two-dimensional direction, the surface dressing accuracy of the grinding head on the polishing pad 55 can be improved, thereby improving the polishing quality of the workpiece 8. When adjusting the perpendicularity of the trimming spindle 46 in the X0Z plane, first loosen the first fastening component 432 to release the locking state between the first housing 42 and the first substrate 41. Then, by operating the first adjustment component 431 on the first substrate 41, drive the first housing 42 to rotate around the Y-axis relative to the first substrate 41 in the forward or reverse direction. After the adjustment is in place, tighten the first fastening component 432 to firmly lock the first housing 42 to the first substrate 41, thus completing the perpendicularity adjustment in the X0Z plane direction. When adjusting the perpendicularity of the trimming spindle 46 in the Y0Z plane, first loosen the second fastening component 442 to release the locking between the first bearing seat 45 and the first housing 42. Then, by operating the second adjustment component 441 on the first housing 42, drive the first bearing seat 45 to rotate around the X-axis relative to the first housing 42 in the forward or reverse direction. Then, tighten the second fastening component 442 to lock the first bearing seat 45 to the first housing 42, thus completing the perpendicularity adjustment in the Y0Z plane direction.

[0050] By using the rotation of the first housing 42 and the first substrate 41 around the Y-axis and the rotation of the first shaft seat 45 and the first housing 42 around the X-axis as adjustment references, and in conjunction with the transmission of the adjustment components, micron-level verticality adjustment can be achieved. This solves the problem of insufficient precision in existing shim adjustment methods and meets the high-precision requirements for surface finishing of large-diameter polishing pads 55. Moreover, the entire process eliminates the cumbersome process of repeated assembly and disassembly, greatly shortening the adjustment time and improving the adjustment efficiency. At the same time, the adjustment stability is good. The first fastening component 432 and the second fastening component 442 securely lock the first housing 42 and the first substrate 41, and the first shaft seat 45 and the first housing 42, respectively, effectively preventing verticality deviation rebound caused by loosening of components after adjustment. This ensures that the finishing spindle 46 can maintain stable verticality accuracy during high-speed operation and long-term use, guaranteeing the consistency of the finishing quality of the polishing pad 55.

[0051] In a preferred embodiment, see [reference] Figure 7 , 8 9, 10, The upper part of the first housing 42 is rotatably connected to the first substrate 41. Specifically, the first housing 42 is fixedly provided with a third rotating shaft 422. The axis of the third rotating shaft 422 is parallel to the Y direction. The third rotating shaft 422 is rotatably connected to the first substrate 41, providing a stable and accurate rotation reference for the rotation of the first housing 42 relative to the first substrate 41.

[0052] The first adjustment assembly 431 includes at least one first adjustment screw 4311 and at least one second adjustment screw 4312. The first adjustment screw 4311 and the second adjustment screw 4312 are symmetrically arranged on both sides of the first substrate 41, and their axes are parallel to the X-direction. The ends of the first adjustment screw 4311 and the second adjustment screw 4312 abut against the bottom sides of the first housing 42. The first adjustment screw 4311 is used to push the first housing 42 to perform forward adjustment around the third rotating shaft 422, and the second adjustment screw 4312 is used to push the first housing 42 to perform reverse adjustment around the third rotating shaft 422. During adjustment, by screwing in or out the first adjusting screw 4311, the bottom of the first housing 42 can be pushed to shift in the corresponding direction. At the same time, the second adjusting screw 4312 on the other side can be turned to make a reverse fine adjustment. Through the lever principle, the first housing 42 is driven to rotate a small angle around the third rotating shaft 422 in the forward direction. Since one rotation of the first adjusting screw 4311 is the straight distance of one screw pitch, combined with the lever arm length of the first housing 42, the angle adjustment accuracy can reach the micrometer level. Similarly, by turning out the first adjusting screw 4311 and screwing in the second adjusting screw 4312, the reverse fine adjustment of the first housing 42 around the third rotating shaft 422 can be achieved, thereby realizing the precise adjustment of the perpendicularity of the trimming spindle 46 in the X0Z plane.

[0053] The first fastening assembly 432 includes a plurality of fastening screws. The first housing 42 is provided with a plurality of mounting holes 421 parallel to the Y direction. The inner diameter of the mounting holes 421 is larger than the outer diameter of the fastening screws. Each fastening screw passes through the corresponding mounting hole 421 and is threadedly connected to the first substrate 41 to achieve a fixed connection between the first housing 42 and the first substrate 41. By setting the inner diameter of the mounting holes 421 to be larger than the outer diameter of the fastening screws, sufficient movement clearance can be reserved for the slight rotation of the first housing 42 around the third rotating shaft 422 during the adjustment of the verticality of the spindle 46 in the X0Z plane. This avoids interference of the fastening screws with the rotation of the first housing 42, ensuring smooth adjustment without affecting the locking and fixing effect after adjustment.

[0054] In a preferred embodiment, see [reference] Figure 7 , 8 9. The X-axis angle adjustment mechanism 44 further includes two second rotating shafts 443 parallel to the X-axis. The two second rotating shafts 443 are symmetrically arranged on both sides of the first housing 42. The two second rotating shafts 443 are rotatably engaged with the first bearing seat 45 respectively. The second adjustment component 441 includes several third adjusting screws 4411 and fourth adjusting screws 4412 parallel to the Y-axis. The third adjusting screws 4411 are screwed to the first housing 42 and their ends abut against the upper part of the first bearing seat 45. The first bearing seat 45 is used to push the first rotating shaft 45 to rotate in the forward direction around the second rotating shaft 443. The fourth adjusting screws 4412 are screwed to the first housing 42 and their ends abut against the lower part of the first bearing seat 45. The first bearing seat 45 is used to push the first rotating shaft 45 to rotate in the reverse direction around the second rotating shaft 443. During adjustment, screwing in the third adjusting screw 4411 pushes the upper part of the first bearing seat 45 toward the first substrate 41, while simultaneously unscrewing the fourth adjusting screw 4412 to reserve rotation space for the lower part of the first bearing seat 45. With the fulcrum of the second rotating shaft 443, the first bearing seat 45 is driven to rotate in the forward X-direction. Conversely, screwing in the fourth adjusting screw 4412 and unscrewing the third adjusting screw 4411 pushes the lower part of the first bearing seat 45 toward the first substrate 41, achieving reverse rotation of the first bearing seat 45 in the X-direction. Similarly, since the pitch of the adjusting screw is fixed, one rotation corresponds to a fixed linear displacement. Combined with the lever arm size of the first bearing seat 45, the angle adjustment accuracy can be controlled at the micrometer level, meeting the correction requirements for the perpendicularity of the trimming spindle 46 in the Y0Z plane. The entire adjustment process does not require disassembling the connection structure between the first bearing seat 45 and the first housing 42, significantly improving adjustment efficiency and ensuring rapid calibration of the perpendicularity of the trimming spindle 46 during the trimming of the large-diameter polishing pad 55.

[0055] The second fastening assembly 442 includes several abutment screws parallel to the X-direction. The abutment screws are symmetrically arranged on both sides of the first housing 42, and their ends abut against the side wall of the first bearing seat 45. After the perpendicularity in the Y0Z plane is adjusted to the correct position, the first bearing seat 45 can be locked in a preset position by tightening each abutment screw.

[0056] Preferably, such as Figure 11 As shown, some of the abutment screws are installed on the same horizontal plane as the third adjusting screw 4411, while the other part of the abutment screws are installed on the same horizontal plane as the fourth screw, forming a double-point abutment. Combined with the symmetrical arrangement of all the abutment screws, a balanced clamping force is formed on the first shaft seat 45, further improving the installation stability of the first shaft seat 45 and effectively counteracting the vibration or external impact generated during the high-speed operation of the dressing spindle 46. Simultaneously, the evenly spaced abutment screws parallel to the second rotating shaft 443 ensure that the direction of the abutment force is perpendicular to the rotation plane of the first shaft seat 45. This does not affect the angular accuracy after adjustment and further enhances the rigidity of the connection between the first shaft seat 45 and the first housing 42, ensuring the stability of the perpendicularity in the Y0Z plane during long-term use of the dressing spindle 46.

[0057] In a preferred embodiment, see [reference] Figure 9 The first bearing seat 45 has a shaft hole 451 extending along the Z direction. The dressing spindle 46 includes a first shaft section 461 rotatably connected to the first bearing seat 45 and a second shaft section 462 connected to the bottom of the first shaft section 461. The first shaft section 461 is rotatably connected to the shaft hole 451, and the cross-section of the first shaft section 461 is I-shaped. The first bearing seat 45 is provided with two third plane throttles 452 and at least one second radial throttle 453. The two third plane throttles 452 form an axial gas film between themselves and the inner end face of the first shaft section 461 by introducing compressed gas. The second radial throttle 453 forms a radial gas film between itself and the peripheral wall of the first shaft section 461 by introducing compressed gas. The dual air film structure, through the principle of gas static pressure support, completely eliminates mechanical contact between the dressing spindle 46 and the first bearing 45. On the one hand, it reduces rotational friction, wear, and heat generation, ensuring the stability of the dressing spindle 46 during high-speed operation. On the other hand, the uniform air film can provide radial and axial restraint for the dressing spindle 46, preventing radial and axial movement of the dressing spindle 46 and further improving the rotational accuracy and perpendicularity retention capability of the dressing spindle 46.

[0058] Preferably, both the planar throttle and the radial throttle are made of graphite material, which has dense pores. The dense pores can form a uniform flow distribution effect on the high-pressure airflow, so as to achieve the formation of a uniformly distributed air film.

[0059] Further, see Figure 9The first bearing seat 45 has a water-blocking cover 48 at its bottom, and the first shaft segment 461 has at least one third annular groove 463 at its bottom. A protrusion 481 is provided on one side of the water-blocking cover 48, which is accommodated within the third annular groove 463. A water-blocking gap exists between the outer circumferential surface of the protrusion 481 and the inner wall of the third annular groove 463. By setting this water-blocking gap, on the one hand, the reserved space allows the first shaft segment 461 to undergo a slight angular deflection with the first bearing seat 45 when the trimming spindle 46 is adjusted vertically in the Y0Z plane, preventing interference between the water-blocking cover 48 and the trimming spindle 46, ensuring smooth adjustment and not affecting the flexibility of verticality adjustment; on the other hand, the nested cooperation between the protrusion 481 and the third annular groove 463 allows the water-blocking gap to naturally form a labyrinthine serpentine channel. When the polishing liquid splashes into the area of ​​the water baffle 48 during the polishing process, the serpentine channel can extend the flow path of the polishing liquid to prevent the polishing liquid from seeping into the air film area and rotating mating surface between the dressing spindle 46 and the first bearing 45, thus preventing the air film stability from being destroyed and ensuring the rotational accuracy and service life of the dressing spindle 46.

[0060] In this embodiment, see Figure 12 The working shaft 3 further includes a second base plate 32, a second housing 33, a second bearing seat 34, and a working spindle 35. The second base plate 32 is slidably connected to the slide table 22 along the Z-direction. The second housing 33 is fixed on the second base plate 32, and the second bearing seat 34 is fixed inside the second housing 33. The working spindle 35 is rotatably connected to the second bearing seat 34. A third drive motor 36 is connected to the top of the second bearing seat 34. The third drive motor 36 is drively connected to the working spindle 35. A movable gripper 312 is fixed to the bottom of the working spindle 35. The third drive motor 36 drives the working spindle 35 to rotate, and the movable gripper 312 rotates accordingly, so as to drive the workpiece 8 to rotate around the axis of the working spindle 35.

[0061] The rotating connection structure between the second bearing 34 and the working spindle 35 is similar to the rotating connection structure between the first bearing 45 and the dressing spindle 46. The specific structure and fit relationship will not be described in detail here, but can be referred to the rotating connection structure between the first bearing 45 and the dressing spindle 46 described above.

[0062] Please see Figure 13 The present invention also provides a polishing method for a composite polishing machine tool, applied to the aforementioned composite polishing machine tool, the polishing method comprising: S01. Trim and groove the polishing pad 55.

[0063] In this embodiment, the finishing process is carried out by mechanical processing, specifically turning or grinding. The surface contour of the polishing pad 55 is mechanically finished by the cutting tool or grinding head on the finishing shaft 4 to initially correct the surface flatness of the polishing pad 55 and remove surface wear impurities. Then, the milling cutter on the finishing shaft 4 is used to mill grooves on the surface of the polishing pad 55. The grooves can provide a flow channel for the polishing liquid and achieve uniform distribution of the polishing liquid on the surface of the polishing pad 55.

[0064] In actual operation, the position and cutting depth of the cutting tool, milling cutter or grinding head can be adjusted by the translation component 21 and the second lifting component 24 to achieve precise control of the dressing amount of the polishing pad 55.

[0065] S02. Clamp the workpiece 8 onto the clamping assembly 31 of the working shaft 3, so that the polished surface of the workpiece 8 faces the polishing pad 55, and place the counterweight 7 on the side of the workpiece 8 away from the polishing pad 55.

[0066] In this embodiment, the first lifting component 23 drives the clamping component 31 of the working shaft 3 to rise, transferring the workpiece 8 to be polished onto the polishing pad 55. Then, the first lifting component 23 drives the clamping component 31 to move downwards, positioning the workpiece 8 within the clamping component 31. Finally, the clamping component 31 is adjusted, with multiple movable jaws 312 and abutment blocks 313 working together to define the position of the workpiece 8. Simultaneously, a counterweight 7 is placed on the upper surface of the workpiece 8, using the gravity of the counterweight 7 to apply stable polishing pressure to the workpiece 8.

[0067] S03. Polishing liquid is dripped onto the surface of polishing pad 55; the working shaft 3 drives the workpiece 8 to rotate at a first preset speed, and the rotating mechanism 52 drives the polishing pad 55 to rotate in the opposite direction at a second preset speed.

[0068] In this embodiment, during the entire polishing process, the polishing liquid is continuously dripped onto the polishing pad 55 to ensure that the polishing liquid flows evenly in the groove and fully wets the polishing surface of the workpiece 8; the working spindle 35 drives the workpiece 8 to rotate smoothly at a first preset speed, and the rotating mechanism 52 drives the polishing pad 55 to rotate in the opposite direction at a second preset speed, so that the workpiece 8 and the polishing pad 55 form a relative polishing motion to ensure the uniformity and consistency of material removal from the polished surface.

[0069] S04. Preset at least three different temperature values, control the variable frequency water chiller 61 to adjust the circulating water to the corresponding temperature and pass it into the flow channel 531; after the first preset polishing time, detect and record the first surface shape accuracy of the polished surface of the workpiece 8.

[0070] In this embodiment, the pressure of the inlet pipe 63 is set to 0.1 MPa via the pressure regulating valve 62, and the output water temperature of the variable frequency water chiller 61 is set to 15℃, 17℃, 19℃, 21℃, and 23℃, corresponding to five polishing experiments. In each polishing experiment, polishing is performed continuously at a constant pressure and corresponding constant temperature for a first preset polishing time. This first preset polishing time is 1 / n1 of the fifth preset polishing time, and the specific duration can be determined according to the actual situation. After the first preset polishing time is completed, the machine is immediately stopped and the workpiece 8 is removed. The first surface shape accuracy results (PV and RMS values) are detected using a laser interferometer and recorded. The first surface shape accuracy detection results are as follows:

[0071] S05. Compare all the first surface accuracy values ​​and select the two temperature values ​​with the best surface accuracy, which are respectively used as the temperature peak and temperature valley values ​​of the thermal fluid temperature field.

[0072] In this embodiment, comparing the above five polishing experiments, the first surface shape accuracy corresponding to T=21℃ and T=15℃ is the best. Therefore, 15℃ is selected as the temperature valley value of the thermal fluid temperature field and 21℃ is selected as the temperature peak value of the thermal fluid temperature field.

[0073] S06. Preset at least three different pressure values, control the pressure regulating valve 62 to pass the hot fluid into the flow channel groove 531 at the corresponding pressure; after the second preset polishing time, detect and record the second surface shape accuracy of the polished surface of the workpiece 8.

[0074] In this embodiment, the output water temperature of the variable frequency water chiller 61 is set to 21℃. The pressure of the inlet pipe 63 is set to 0.1MPa, 0.09MPa, 0.085MPa, 0.08MPa, and 0.075MPa via the pressure regulating valve 62, corresponding to five polishing experiments. Each group is polished continuously at a constant temperature and corresponding pressure for a second preset time, which is also 1 / n² of the fifth preset polishing time. After the second preset polishing time is completed, the machine is immediately stopped and the workpiece 8 is removed. The second surface shape accuracy PV and RMS values ​​are measured using the same laser interferometer and recorded. The results of the second surface shape accuracy test are as follows:

[0075] S07. Compare all the second surface accuracy values ​​and select the two pressure values ​​with the best surface accuracy as the pressure peak and pressure valley values ​​of the thermal fluid temperature field, respectively.

[0076] In this embodiment, comparing the above five sets of polishing experiments, the second surface shape accuracy corresponding to the water inlet pipe pressure of 0.08MPa and the water inlet pipe 63 pressure of 0.75MPa is the best. Therefore, 0.075MPa is selected as the pressure valley value of the hot fluid pressure field and 0.08MPa is selected as the pressure peak value.

[0077] S08. Pre-set at least two periodic temperature-time curves of different types. The periodic temperature-time curves are defined by temperature peaks and temperature valleys. Control the hot fluid to flow into the flow channel groove 531 according to the corresponding curves. After a third preset polishing time, detect and record the third surface shape accuracy, and select the optimal curve as the final temperature-time curve.

[0078] In this embodiment, the pressure of the inlet pipe 63 is set to 0.1 MPa by the pressure regulating valve 62, and three types of periodic temperature-time curves, namely sine wave, triangular wave and square wave, are set, with 15℃ as the valley value and 21℃ as the peak value. The period T1 is 1 / n3 of the third preset polishing time. The specific duration can be determined according to the actual situation. The three types of curves drive the hot fluid to circulate into the flow channel 531 respectively. After each group completes the third preset polishing time, the machine is stopped immediately and the third surface accuracy PV and RMS values ​​are measured. The third preset polishing time is 1 / n4 of the fifth preset polishing time. Finally, the optimal curve is selected as the final temperature-time curve based on the test results.

[0079] S09. Pre-set at least two periodic pressure-time curves of different types. The periodic pressure-time curves are defined by pressure peak and pressure valley values. Control the hot fluid to flow into the flow channel groove 531 according to the corresponding curve. After a fourth preset polishing time, detect and record the fourth surface accuracy, and select the optimal curve as the final pressure-time curve.

[0080] In this embodiment, the output water temperature of the variable frequency water chiller 61 is set to 21℃, and three types of periodic pressure-time curves—sine wave, triangular wave, and square wave—are set, each with a valley value of 0.075MPa and a peak value of 0.08MPa. The period T2 is 1 / n5 of the fourth preset polishing time. The three types of curves drive the hot fluid to circulate into the flow channel 531. After each group completes the fourth preset polishing time, the machine is immediately stopped to measure the fourth surface accuracy PV and RMS values, where the fourth preset polishing time is 1 / n6 of the fifth preset polishing time. Finally, the optimal curve is selected as the final pressure-time curve based on the test results.

[0081] S10 controls the variable frequency water chiller 61 and pressure regulating valve 62 to regulate the hot fluid according to the final temperature-time curve and the final pressure-time curve, respectively, until the fifth preset polishing time ends, thus completing the polishing.

[0082] In this embodiment, based on the optimal process parameters obtained from the aforementioned steps, the variable frequency water chiller 61 and the pressure regulating valve 62 are coordinated to operate according to the finally determined periodic curve. The variable frequency water chiller 61 uses 15°C as the temperature valley and 21°C as the temperature peak, and periodically adjusts the circulating water temperature according to the final temperature-time curve. The pressure regulating valve uses 0.075MPa as the pressure valley and 0.08MPa as the pressure peak, and periodically adjusts the circulating water pressure according to the final pressure-time curve, so that the hot fluid is circulated into the vortex with optimal dynamic temperature and pressure parameters. The flow channel 531 forms a stable and adaptable dynamic thermal fluid field within the heating stage 53. This dynamic thermal fluid field continuously induces the polishing disk 54 to produce precise dynamic elastic deformation, which in turn drives the polishing pad 55 to adapt synchronously. Combined with the reverse relative polishing motion of the workpiece 8 and the polishing pad 55, the polishing surface of the workpiece 8 is continuously and uniformly and efficiently shaped and polished. The above-mentioned dynamic temperature control and pressure adjustment polishing process continues until the end of the fifth preset polishing time, finally completing the ultra-precision polishing of the workpiece 8 and maximizing the surface shape accuracy and surface quality of the polished surface of the workpiece 8.

[0083] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A composite polishing machine tool, characterized in that, include: Base (1); The transmission mechanism (2) is mounted on the base (1); The working shaft (3) is mounted on the transmission mechanism (2), which drives the working shaft (3) to translate along the X direction and / or move up and down along the Z direction; the working shaft (3) is provided with a clamping assembly (31) that can rotate around the Z direction, and the clamping assembly (31) is used to clamp the workpiece (8). The dressing shaft (4) is mounted on the transmission mechanism (2). The transmission mechanism (2) drives the dressing shaft (4) to translate along the X direction and / or move up and down along the Z direction. The dressing shaft (4) is equipped with a milling cutter, a turning tool and a grinding head that can rotate around the Z-axis. A turntable (5) is mounted on a base (1). The turntable (5) includes a base (51), a rotating mechanism (52), a heating table (53), and a polishing disc (54). The rotating mechanism (52) is mounted on the base (51), and the heating table (53) is mounted on the rotating mechanism (52). The rotating mechanism (52) drives the heating table (53) to rotate around the Z-axis. The heating table (53) is connected to a heating assembly (6). The polishing disc (54) is mounted on the top of the heating table (53). The heating assembly (6) is used to heat the polishing disc (54). The polishing disc (54) is mounted on the top of the polishing disc (54). The polishing pad (55) is used to contact the polishing surface of the workpiece (8).

2. The composite polishing machine tool according to claim 1, characterized in that, The heating assembly (6) includes a variable frequency water chiller (61), a pressure regulating valve (62), an inlet pipe (63), and an outlet pipe (64). The heating platform (53) has a vortex-shaped flow channel groove (531) on the side facing the polishing disc (54). The outlet end of the variable frequency water chiller (61), the pressure regulating valve (62), the inlet pipe (63), and the inlet end of the flow channel groove (531) are connected in sequence. The outlet end of the flow channel groove (531), the outlet pipe (64), and the inlet end of the variable frequency water chiller (61) are connected in sequence.

3. The composite polishing machine tool according to claim 1, characterized in that, The polishing disc (54) includes at least one connecting platform (541), each connecting platform (541) is stacked sequentially along the Z direction and fixed on the top of the heating platform (53), and the thermal expansion coefficients of each connecting platform (541) are different.

4. The composite polishing machine tool according to claim 1, characterized in that, The rotating mechanism (52) includes a first drive motor (521), a first rotating shaft (522), a support member (523), and a gas static pressure bearing (524). The first drive motor (521) is mounted on the base (51). The output end of the first drive motor (521) is connected to the first rotating shaft (522) for transmission. The cross-section of the first rotating shaft (522) is I-shaped. The support member (523) is mounted on the base (51) and sleeved on the outer circumference of the first rotating shaft (522). The first rotating shaft (522) is rotatably connected to the support member (523) through the gas static pressure bearing (524).

5. The composite polishing machine tool according to claim 4, characterized in that, The gas static pressure bearing (524) includes a first planar throttling assembly, a second planar throttling assembly, and a first radial throttling device (5241); the first rotating shaft (522) includes an upper static pressure plate (5221), a spindle (5222), and a lower static pressure plate (5223) that are fixedly connected in sequence. The first radial throttle (5241) is installed between the outer peripheral surface of the spindle (5222) and the inner wall of the support (523). The support (523) has a first through hole (5231) for introducing compressed gas into the first radial throttle (5241). The upper end face of the support member (523) is provided with at least one first annular groove (5232), the first planar throttling component includes a number of first planar throttling devices (5242) arranged in a circumferential array and embedded in the first annular groove (5232), and the support member (523) is provided with a number of second through holes (5233) corresponding one-to-one with the first planar throttling devices (5242). The lower end face of the support member (523) is provided with at least one second annular groove (5234), the second planar throttling assembly includes several second planar throttling devices (5243) arranged in a circumferential array and embedded in the second annular groove (5234), and several third through holes (5235) corresponding one-to-one with the second planar throttling devices (5243) are provided in the support member (523).

6. The composite polishing machine tool according to claim 1, characterized in that, The clamping assembly (31) includes a fixed disk (311) and a number of movable jaws (312) arranged in a circumferential array on the fixed disk (311). Each movable jaw (312) is provided with a number of abutment blocks (313) for abutting against the outer peripheral surface of the workpiece (8).

7. The composite polishing machine tool according to claim 1, characterized in that, The trimming shaft (4) includes a first base plate (41), a first housing (42), a Y-axis angle adjustment mechanism (43), an X-axis angle adjustment mechanism (44), a first shaft seat (45), and a trimming spindle (46). The first housing (42) is rotatably connected to the first substrate (41) about the Y-axis; the Y-axis angle adjustment mechanism (43) includes a first adjustment component (431) and a first fastening component (432). The first adjustment component (431) is disposed on the first substrate (41) and is used to drive the first housing (42) to rotate about the Y-axis relative to the first substrate (41); the first fastening component (432) is disposed between the first substrate (41) and the first housing (42) and is used to lock the first housing (42) to the first substrate (41). The first bearing seat (45) is housed within the first housing (42) and is rotatably connected to the first housing (42) about the X-axis. The X-axis angle adjustment mechanism (44) includes a second adjustment component (441) and a second fastening component (442). The second adjustment component (441) is disposed on the first housing (42) and is used to drive the first bearing seat (45) to rotate relative to the first housing (42) about the X-axis. The second fastening component (442) is disposed on the first housing (42) and is used to lock the first bearing seat (45) to the first housing (42). The dressing spindle (46) is rotatably connected to the first bearing seat (45) along the Z-axis. The top of the first bearing seat (45) is connected to the second drive motor (47), and the second drive motor (47) is connected to the upper end of the dressing spindle (46) for transmission. The milling cutter and the turning tool are fixed at the bottom of the first housing (42); the grinding head is fixed at the lower end of the dressing spindle (46).

8. The composite polishing machine tool according to claim 7, characterized in that, The upper part of the first housing (42) is rotatably connected to the first substrate (41). The first adjustment assembly (431) includes at least one first adjustment screw (4311) and at least one second adjustment screw (4312). The first adjustment screw (4311) and the second adjustment screw (4312) are symmetrically arranged on both sides of the first substrate (41) and their axes are parallel to the X direction. The ends of the first adjustment screw (4311) and the second adjustment screw (4312) abut against the bottom of both sides of the first housing (42). The first fastening assembly (432) includes a plurality of fastening screws. The first housing (42) is provided with a plurality of mounting holes (421) parallel to the Y direction. The inner diameter of the mounting hole (421) is larger than the outer diameter of the fastening screw. Each fastening screw passes through the corresponding mounting hole (421) and is threadedly connected to the first substrate (41).

9. The composite polishing machine tool according to claim 7, characterized in that, The X-axis angle adjustment mechanism (44) further includes two second rotating shafts (443) parallel to the X-axis. The two second rotating shafts (443) are symmetrically arranged on both sides of the first housing (42), and the two second rotating shafts (443) are rotatably engaged with the first bearing seat (45). The second adjustment component (441) includes several third adjustment screws (4411) and fourth adjustment screws (4412) parallel to the Y-axis. The third adjustment screws (4411) are screwed to the first housing (42), and their ends abut against the upper part of the first bearing seat (45). The fourth adjustment screws (4412) are screwed to the first housing (42), and their ends abut against the lower part of the first bearing seat (45). The second fastening component (442) includes several abutting screws parallel to the X-axis. The multiple abutting screws are symmetrically arranged on both sides of the first housing (42), and their ends abut against the side wall of the first bearing seat (45).

10. A polishing method for a composite polishing machine tool, characterized in that, Applied to the composite polishing machine tool as described in claim 2, the polishing method includes: The polishing pad (55) is trimmed and grooved; The workpiece (8) is clamped onto the clamping assembly (31) of the working shaft (3), so that the polished surface of the workpiece (8) faces the polishing pad (55), and a counterweight (7) is placed on the side of the workpiece (8) away from the polishing pad (55). Polishing liquid is dripped onto the surface of the polishing pad (55); the working shaft (3) drives the workpiece (8) to rotate at the first preset speed, and the rotating mechanism (52) drives the polishing pad (55) to rotate in the opposite direction at the second preset speed; At least three different temperature values ​​are preset, and the variable frequency water chiller (61) is controlled to adjust the circulating water to the corresponding temperature and pass it into the flow channel groove (531); after the first preset polishing time, the first surface shape accuracy of the polished surface of the workpiece (8) is detected and recorded; Comparing all the first surface accuracy, the two temperature values ​​with the best surface accuracy are selected as the temperature peak and temperature valley values ​​of the thermal fluid temperature field, respectively. At least three different pressure values ​​are preset, and the pressure regulating valve (62) is controlled to introduce hot fluid into the flow channel groove (531) at the corresponding pressure; after the second preset polishing time, the second surface shape accuracy of the polished surface of the workpiece (8) is detected and recorded; By comparing all the second surface accuracy, the two pressure values ​​with the best surface accuracy are selected and used as the pressure peak and pressure valley values ​​of the thermal fluid temperature field, respectively. At least two different types of periodic temperature-time curves are preset. The periodic temperature-time curves are defined by temperature peaks and temperature valleys. The hot fluid is controlled to flow into the flow channel groove (531) according to the corresponding curves. After a third preset polishing time, the third surface accuracy is detected and recorded. The optimal curve is selected as the final temperature-time curve. At least two different types of periodic pressure-time curves are preset. The periodic pressure-time curves are defined by pressure peak and pressure valley values. The hot fluid is controlled to flow into the flow channel groove (531) according to the corresponding curve. After a fourth preset polishing time, the fourth surface accuracy is detected and recorded. The optimal curve is selected as the final pressure-time curve. The variable frequency water chiller (61) and pressure regulating valve (62) are controlled to regulate the heat fluid according to the final temperature-time curve and the final pressure-time curve, respectively, until the fifth preset polishing time ends, and the polishing is completed.

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