In-situ polishing device and method for large-aperture composite material antenna reflector

Abstract

The application provides a large-diameter composite antenna reflector in-situ polishing device and method. The method comprises a low-stress clamping module, a motion module, a processing module, an electrical module and a circulation module. The low-stress clamping module is used for realizing low-stress flexible clamping of the antenna reflector sample, the processing module is used for realizing processing of the antenna reflector sample through a processing tool, the motion module is used for realizing spatial motion of the processing tool, the electrical module is used for providing various conditions required in the processing, and the circulation module is used for circulation and filtration of trace lubricating liquid. The device adopts a method of adding nano particles to the atomized green lubricating liquid to reduce the amount of lubricating liquid, thereby reducing the cost and environmental pollution. The device realizes low-stress flexible clamping of the large-diameter antenna reflector sample by using phase change of modified low-melting-point paraffin, thereby avoiding repeated positioning difficulties caused by multiple clamping and unloading of the large-diameter antenna reflector sample.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical manufacturing, in particular, especially relates to a large aperture composite antenna reflector in situ polishing device and method. BACKGROUND

[0002] As a core component of high-end equipment, large aperture antenna is widely used in the fields of aviation, communication, weapon, etc., and belongs to the national major demand. The precision and aperture of the antenna reflector directly affect the important indicators such as the spatial resolution, sensitivity, calibration accuracy, polarization isolation of the detection instrument, so the machining precision of the large aperture antenna reflector is an important factor affecting the high performance detection system.

[0003] The traditional clamping methods are all through the machining of metal conformal mold or the method of multi-point support, the former has the disadvantages of high processing cost, long cycle and complicated processing procedure, and the latter causes insufficient rigidity of the part when machining in the place without support, causing vibration.

[0004] Although the traditional grinding has high material removal efficiency, since the resin matrix in the composite material has poor heat resistance, when the grinding temperature exceeds the glass transition temperature, the resin softens and is embedded in the gap between the abrasive grains, causing the wheel to be blocked, losing the grinding ability, and causing the risk of ablation of the resin surface. Moreover, after traditional grinding, the antenna needs to be disassembled to measure the size, surface precision, etc., the process is complicated, the cost is high and the machining precision is difficult to guarantee. Therefore, the current machining method cannot meet the requirements of high surface precision of large aperture antenna reflector. SUMMARY

[0005] According to the above technical problems, a large aperture antenna reflector in situ polishing device and method are provided. The present application adopts low stress flexible clamping to reduce the surface change before and after the antenna clamping, uses trace nanofluid to reduce the abrasion and heat conduction auxiliary grinding and negative pressure liquid discharge method to reduce the blockage of the grinding wheel, which can ensure the successful completion of the high precision polishing of the large aperture antenna reflector.

[0006] The technical means adopted by the present application is as follows:

[0007] A large aperture antenna reflector in situ polishing device, comprising a low stress clamping module, a motion module, a processing module, an electrical module and a circulation module; wherein: the low stress clamping module is used to realize the low stress flexible clamping of the antenna reflector sample, the processing module is used to realize the processing of the antenna reflector sample through the processing tool, the motion module is used to realize the spatial motion of the processing tool, the electrical module is used to provide various conditions required in the processing process, and the circulation module is used to circulate and filter the trace lubricating liquid.

[0008] Further, the low-stress clamping module comprises a vacuum adsorption base, a support platform, a moving platform, a plastic film, a support material, a rotary joint, a heating module, a temperature sensing module, a force sensing module, a pressurizing pump, a vacuum pump and a support material storage tank; wherein the vacuum adsorption base is connected with the vacuum pump, the support platform is installed inside the vacuum adsorption base, the vacuum adsorption base is fixed on the moving platform by vacuumizing, the vacuum adsorption base is used for fixing the support platform and fixing the part to be processed, the output end of the support material storage tank is connected with the connecting port of the outer sidewall of the support platform through the pressurizing pump and the rotary joint, the rotary joint realizes the switching of inflow / outflow of the support material by adjusting the rotation angle, the heating module is used for heating the support material, realizing the stress relief treatment of the part to be processed and the disassembly of the part, the plastic film is used for avoiding the direct contact between the support material and the part to be processed, the temperature sensing module is used for monitoring the temperature of the support material, the force sensing module is used for monitoring the stress distribution of the support material in the process of clamping and processing the part to be processed, and the output of the heating coil is adjusted based on the monitoring values of the temperature sensing module and the force sensing module.

[0009] Further, the moving module comprises a moving platform and a machining tool moving device arranged on the moving platform, the moving platform can realize Y-direction movement of the clamping device, the first lead screw and the linear guide are used for realizing Z-direction movement of the grinding wheel, and the second lead screw and the linear guide are used for realizing X-direction movement of the grinding wheel.

[0010] The machining module comprises a power source, a grinding wheel, a laser displacement sensor and a plurality of micro-lubrication nozzles; the power output by the power source realizes high-speed rotation of the grinding wheel; the laser displacement sensor is used for realizing synchronous measurement of surface topography in the process of machining; micro-lubricating liquid enters each micro-lubrication nozzle through the rotary joint to realize friction reduction and cooling in the process of machining; the lubricating liquid is composed of dimethyl silicone oil added with multi-walled carbon nanotubes and spherical silica colloids, the multi-walled carbon nanotubes can improve the heat conduction performance of the lubricating liquid and reduce the grinding force in the process of grinding, and the addition of spherical silica colloids can improve the material removal efficiency and has a certain sharpening effect on the grinding wheel; each micro-lubrication nozzle can rotate, so that the lubricating liquid is sprayed more uniformly and sufficiently to the machining area, and the lubricating liquid enters the circulation system from the micropores on the surface of the grinding wheel based on the negative pressure effect to realize recycling.

[0011] Further, the circulation module comprises a lubricating liquid storage tank and a plurality of ultrasonic vibration heads, cooling pipes and gradient foams arranged on the tank; the ultrasonic vibration heads are used for fully mixing and uniformly distributing the lubricating liquid and avoiding clogging of the gradient foams by grinding dust; the pore diameter of the gradient foams decreases along with the increase of the liquid level in the lubricating liquid storage tank, and the pore diameter is 2mm-5mm, and the porosity of the gradient foams is 40%-60%.

[0012] Furthermore, the shape of the support platform is designed to conform to the shape of the part to be processed, achieving equal stress clamping. The support platform has through holes along the axial direction, which serve as vacuum adsorption channels for vacuum adsorption of the part to be processed. The support platform has radial through holes on its side to allow the gas in the cavity formed by the support platform and the plastic film to overflow when the support material is filled. The sealing plug is used to block the radial through holes on the side of the support platform when the support material is added, preventing the oxidation of the multi-walled carbon nanotubes by oxygen during the post-processing of the part to be processed. The sealing plug is truncated cone-shaped, and the inner surface of the support platform has a heat-insulating coating, which is an aerogel nano-heat-insulating coating.

[0013] Furthermore, the heating module consists of several coils, including a strip heating module and a ring heating module. The strip heating module is installed on the inner side wall of the support platform, and the ring heating module is installed in a ring on the inner bottom surface of the support platform. Each coil is a single unit and can be individually controlled to achieve precise control of the heating area. The switching of the coil is controlled by a combination of temperature sensing patches and force sensing patches to achieve low-stress clamping of the workpiece to be processed.

[0014] Furthermore, the temperature sensing module includes a first temperature sensing patch group, a second temperature sensing patch group, and a third temperature sensing patch group; the first temperature sensing patch group is attached to the back of the part to be processed, and the first and second temperature sensing patch groups are respectively attached to the inner bottom surface and inner side surface of the support platform. The first, second, and third temperature sensing patch groups are used to realize the temperature distribution pattern of the support material poured into the support platform, stress relief post-processing, and processing. Temperature distribution detection: The first and third temperature sensing patch groups are arranged according to a leaf sequence, and the distance between two adjacent temperature sensing patches is a preset value; The force sensing module includes a first force sensing patch group and a second force sensing patch group. The first force sensing patch group is set on the support platform at the mating point with the flange of the part to be processed, and the second force sensing patch group is attached to the back of the part to be processed to detect and monitor the stress distribution during clamping and processing. The force sensing patches are embedded in the intervals of the temperature sensing patches.

[0015] Furthermore, one side of the plastic film has a heat-resistant adhesive that does not react with the part to be processed, which is used to perfectly adhere the plastic film to the lower surface of the part to be processed, and the other side of the plastic film has several protrusions.

[0016] Furthermore, the supporting material is a low-melting-point phase change material, including paraffin with added multi-walled carbon nanotubes.

[0017] The present invention also provides an in-situ grinding and polishing method for a large-aperture antenna reflector sample, comprising the following steps:

[0018] S1: Place the vacuum adsorption base on the moving platform, and place the support platform on the vacuum adsorption base, open the vacuum pump to fix it by vacuumizing;

[0019] S2: Paste the force sensing patch on the back of the antenna reflector sample according to the phyllotaxis;

[0020] S3: Paste the temperature sensing patch on the inner surface of the support platform and the back of the antenna reflector sample according to the phyllotaxis;

[0021] S4: Paste the plastic film on the back of the antenna reflector sample;

[0022] S5: Place the antenna reflector sample on the support platform, and make the antenna reflector sample flange lower surface contact with the concave platform on the upper surface of the support platform, open the vacuum pump to fix it by vacuumizing;

[0023] S6: Open the pressurizing pump to inject the liquid support material into the support platform through the rotary joint, adjust the speed of the rotary joint injection and the switch of the coil in the heating module according to the temperature and stress sensing patch on the part and the support platform;

[0024] S7: When the liquid surface of the support material coincides with the notch on the rotary joint, stop the injection of the support material;

[0025] S8: According to the stress distribution on the surface of the antenna reflector sample during the curing process of the support material, adjust the switch of the heating coil, and then realize the low stress clamping of the antenna reflector sample;

[0026] S9: Turn off the heating module, and plug the sealing plug into the radial through hole on the side surface of the support platform;

[0027] S10: Measure the surface profile information of the antenna reflector sample by using the laser displacement sensor, and reconstruct the three-dimensional model;

[0028] S11: According to the reconstructed three-dimensional model information and the theoretical model, plan the path of grinding and polishing of the antenna reflector sample;

[0029] S12: Rotate the main shaft, open the circulating system, spray lubricating liquid, and start grinding and polishing the antenna reflector sample according to the path planned in S11, and the laser displacement sensor measures the surface profile of the antenna reflector sample synchronously and reconstructs the three-dimensional model during the process;

[0030] S13: After the antenna reflector sample is processed, stop the rotation of the main shaft, turn off the circulating system, turn on the heating module for 20-50 min to heat to 55-65℃, keep warm for 15-30 min, cool down to 15℃ for 1-1.5h, keep warm for 25-50 min, repeat the above heating and cooling steps for 2-5 times to achieve the purpose of stress relief.

[0031] S14: repeat S10;

[0032] S15: repeat S10-S14 until the reconstructed three-dimensional model reaches the required surface accuracy;

[0033] S16: turn on the heating module for 15-25 min to heat up to the melting point of the support material, open the true adsorption base, and disassemble the antenna reflector sample piece.

[0034] Compared with the prior art, the present application has the following advantages:

[0035] (1) The device uses the method of atomizing and adding nano-particles of green lubricating liquid to reduce the amount of lubricating liquid, reduce the cost and environmental pollution; (2) The device realizes low-stress flexible clamping of large-diameter antenna reflector sample pieces by using the phase change of modified low-melting-point paraffin; (3) The device realizes equal-stress flexible clamping of large-diameter antenna reflector sample pieces by adjusting the range and speed of solidification of modified low-melting-point paraffin; (4) The device realizes stress relief treatment of large-diameter antenna reflector sample pieces after processing by melting modified low-melting-point paraffin, reduces the processing cost, and avoids the repeated positioning difficulties caused by multiple clamping and unloading of large-diameter antenna reflector sample pieces; (5) The clamping device and method have universality and can be widely applied to traditional lathes, milling machines, grinding machines and new laser processing machines. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0037] Figure 1 is a perspective view of the device.

[0038] Figure 2 is a schematic view of the main shaft module.

[0039] Figure 3 is a schematic view of the control module, lubricating liquid module and clamping module.

[0040] Figure 4 is a schematic view of the part to be processed with a pressure sensing patch and a temperature sensing patch.

[0041] Figure 5 is a schematic view of the antenna reflector sample piece with a pressure sensing patch and a temperature sensing patch.

[0042] Figure 6 Figure is a schematic view of an antenna reflector sample.

[0043] Figure 7 Figure is a schematic view of a plastic film.

[0044] Figure 8 Figure is a schematic view of a gradient foam structure.

[0045] 1, motion platform; 2, first high-precision motor; 3, shaft coupling; 4, first support base; 5, first lead screw; 6, cross beam; 7, linear guide rail; 8, lead screw bearing; 9, second support base; 10, third support base; 11, linear guide rail slider; 12, second high-precision motor; 13, first gear; 14, connecting plate; 15, base; 16, second lead screw; 17, fourth support base; 18, fifth support base; 19, linear guide; 20, third high-precision motor; 21, linear guide slider; 22, sixth support base; 23, first rotary joint; 24, second rotary joint; 25, spindle base; 26, first laser displacement sensor; 27, first microlubrication nozzle; 28, second microlubrication nozzle; 29, grinding wheel; 30, second laser displacement sensor; 31, third microlubrication nozzle; 32, spindle; 33, second gear; 34, control cabinet; 35, support material storage tank; 36, vacuum pump; 37, pressure pump; 38, laser system; 39, first sealing plug; 40, second sealing plug; 41, third rotary joint; 42, rotary joint four; 43, antenna reflector sample; 44, plastic film; 45, support platform; 46, fourth rotary joint; 47, sixth rotary joint; 48, third sealing plug; 49, lubricating liquid storage tank; 50, first ultrasonic vibration head; 51, second ultrasonic vibration head; 52, third ultrasonic vibration head; 53, fourth ultrasonic vibration head; 54, fifth ultrasonic vibration head; 55, cooling pipe; 56, vacuum adsorption base; 57, ring-shaped heating module; 58, first temperature sensing patch group; 59, second temperature sensing patch group; 60, strip-shaped heating module; 61, first force sensing patch group; 62, second force sensing patch group; 63, third temperature sensing patch group. DETAILED DESCRIPTION

[0046] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with embodiments.

[0047] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The following description of at least one example embodiment is merely illustrative in nature and is in no way limiting on the application or its applications or uses. Based upon a review of the embodiments contained herein, those of ordinary skill in the art can make other embodiments that are within the scope of the application without undue experimentation. Persons of ordinary skill in the art will understand that all other embodiments that are within the scope of the present application are contemplated and fall within the scope of the present application.

[0048] It is to be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0049] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the application unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale as the dimensions of the parts shown are for the purpose of providing an illustration of the application only and can not reflect the actual proportions of the parts. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail but can be assumed known to the person of ordinary skill in the art. In all examples shown and discussed herein, any specific value should be interpreted as illustrative only and not as a limitation. Thus, other examples of the example embodiments can have different values. It is noted that like numbers and letters on the figures identify like parts throughout the several views, and therefore, once a part has been defined in one figure, it is not necessary to discuss it further in connection with other figures unless explicitly stated.

[0050] In the description of the present application, it needs to be understood that the orientation words such as "front, back, upper, lower, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship are generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, without the opposite indication, these orientation words do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the present application: the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0051] For the purposes of this description, spatially relative terms, such as "above", "below", "up", "down", "between", "within", "left", "right", "front", "back", "upper", "lower", "horizontal", "vertical", "above", "below", "up", "down", "top", "bottom", "side", "end", etc., are intended to describe the orientation of one device or feature relative to another device or feature as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. For example, if a device in the figures is turned over, elements described as "above" other elements or "below" other elements will then be oriented "below" other elements or "above" other elements, respectively. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0052] In addition, it should be noted that the use of "first", "second", and the like words of distinction do not have a special meaning, and are only used to distinguish corresponding parts, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0053] As shown in Figures 1-8 , the embodiment of the present application discloses a large-diameter composite antenna reflector in-situ polishing device, which comprises a low-stress clamping module, a motion module, a processing module, an electrical module and a circulation module; wherein: the low-stress clamping module is used to realize the low-stress flexible clamping of the antenna reflector sample, the motion module is used to realize the spatial motion of the grinding wheel, the processing module is used to realize the processing of the antenna reflector sample, the electrical module is used to provide various conditions required in the processing, and the circulation module is used to circulate and filter the trace lubricating liquid; in this paper, X, Y and Z are the same as the commonly used machine tool coordinate system.

[0054] As shown in Figure 3 , the flexible low-stress clamping module comprises a motion platform 1, a support material, a sealing plug 39, a sealing plug 40, a rotary joint 41, a rotary joint 42, a plastic film 44, a support platform 45, a rotary joint 46, a rotary joint 47, a sealing plug 48, a vacuum adsorption base 56, a heating module, a temperature sensing module, a force sensing module; wherein:

[0055] The vacuum adsorption base 56 is fixed on the motion platform 1 by the pressure difference formed by the vacuum pump 36 sucking out the air inside the vacuum adsorption base 56, and the support platform 45 is adsorbed on the upper surface of the vacuum adsorption base 56, the vacuum adsorption base 56 is divided into two parts, one part is used to fix the support platform 45, and the other part is used to fix the antenna reflector sample 43.

[0056] The shape of the support platform 45 is designed according to the shape of the antenna reflector sample 43, and equal stress clamping is realized. The support platform 45 is provided with a through hole in the axial direction, which is used as a vacuum adsorption channel for vacuum adsorption of the antenna reflector sample 43. The support platform 45 has a radial through hole on the side, which is used to support the overflow of the gas in the inner cavity formed by the support platform 45 and the plastic film 44 when the support material is filled. The first sealing plug 39, the second sealing plug 40 and the third sealing plug 48 are used to block the radial through hole on the side of the support platform 45 when the support material is added, so as to avoid the oxidation of the multi-walled carbon nanotubes by oxygen during the post-processing of the antenna reflector sample 43. The first sealing plug 39, the second sealing plug 40 and the third sealing plug 48 are conical frustums, which can achieve good sealing effect. The position of the sealing plug should be higher than the scale line of the rotating head. The inner surface of the support platform 45 has a heat insulation coating, which is selected from aerogel nano thermal insulation paint, and the thermal conductivity of which can be 0.03 W / m·k.

[0057] The heating module is composed of a plurality of coils, which are used to heat the support material and further realize the stress relief treatment of the antenna reflector sample 43 and the disassembly of the sample. The coils are divided into strip-shaped heating modules and ring-shaped heating modules. The strip-shaped heating modules are installed on the inner side wall of the support platform, and the ring-shaped heating modules are installed on the inner bottom surface of the support platform in a ring shape. The coils are single units and can be controlled by switches independently to realize accurate control of the heating area. The switches of the coils are controlled by the comprehensive feedback of the temperature sensing patches and the force sensing patches to realize low stress clamping of the antenna reflector sample 43.

[0058] The temperature sensing module includes a first temperature sensing patch group 58, a second temperature sensing patch group 59 and a third temperature sensing patch group 63. The third temperature sensing patch group 63 is attached to the back of the antenna reflector sample 43, the first temperature sensing patch group 58 and the second temperature sensing patch group 59 are attached to the inner bottom surface and the inner side surface of the support platform 45, which can be used to detect the temperature distribution of the support material poured into the support platform 45, the temperature distribution during the stress relief post-processing and processing. The first temperature sensing patch group 58 and the third temperature sensing patch group 63 are arranged according to the phyllotaxis rule, and the distance between two adjacent temperature sensing patches is 5mm, so that the internal temperature rule can be accurately and detailedly understood with the least temperature sensing patches.

[0059] The force sensing module includes a first force sensing patch group 61 and a second force sensing patch group 62. The first force sensing patch group 61 is attached to the support platform 45 at the cooperation position of the folded edge of the antenna reflector sample 43, and the second force sensing patch group 62 is attached to the back of the antenna reflector sample 43, which can be used to detect and monitor the stress distribution during clamping and processing. The force sensing patches are embedded in the intervals of the temperature sensing patches.

[0060] The side of the plastic film 44 is provided with heat-resistant adhesive which does not react with the antenna reflector sample 43, for perfect bonding of the plastic film 44 with the lower surface of the antenna reflector sample 43, and avoiding direct contact of the supporting material with the antenna reflector sample 43; and the other side surface of the plastic film 44 is provided with a plurality of protrusions, for improving the bonding force of the plastic film 44 with the supporting material, and further improving the stability of supporting the antenna reflector sample 43 in the processing process.

[0061] The supporting material is a low-melting point phase change material, and the preferred low-melting point phase change material of the present application is paraffin with a melting point of 40℃ and added with 0.6% (wt) multi-walled carbon nanotubes. The modified paraffin has the advantages of good flow and high thermal conductivity (increased by 45% compared with the unmodified one). In the embodiment, since the antenna reflector sample is generally made of carbon fiber resin-based composite material, and the glass transition temperature of the resin is relatively low, generally 100-300℃, the paraffin with a melting point of 40℃ is selected in consideration of the relatively high room temperature in some areas of China in summer, the minimum energy consumption for melting the paraffin, and the minimum influence on the resin material.

[0062] One end of the third rotary joint 41, the fourth rotary joint 42, the fifth rotary joint 46 and the sixth rotary joint 47 is connected with the connecting hole of the outer side wall of the supporting platform 45, and the other end is connected with the pressurizing pump 37, and the other end of the pressurizing pump 37 is connected with the supporting material storage tank 35. The rotary joint realizes the switching of inflow / outflow of the supporting material by rotating 180°. The third rotary joint 41, the fourth rotary joint 42, the fifth rotary joint 46 and the sixth rotary joint 47 are transparent, which is convenient for observing the height of the supporting material inside the supporting platform 45.

[0063] The motion module comprises a motion platform 1 and a first high-precision motor 2, a shaft coupling 3, a first support seat 4, a first lead screw 5, a cross beam 6, a linear guide rail 7, a lead screw bearing 8, a second support seat 9, a third support seat 10, a linear guide rail slider 11, a connecting plate 14, a base 15, a second lead screw 16, a fourth support seat 17, a fifth support seat 18, a linear guide 19, a third high-precision motor 20, a linear guide slider 21 and a sixth support seat 22 arranged on the base 15; wherein: the upper half and the lower half of the motion platform 1 can move relatively to realize the Y-direction movement of the clamping device, the first lead screw 5 and the linear guide 19 are used to realize the Z-direction movement of the grinding wheel 29, and the second lead screw 16 and the linear guide rail 7 are used to realize the X-direction movement of the grinding wheel 29; specifically, the first high-precision motor 2 is connected with the first lead screw 5 through the shaft coupling 3, the lower end of the first lead screw 5 is arranged in the first support seat 4, the upper end is arranged in the third support seat 10, the linear guide 19 is arranged in parallel with the first lead screw 5, the upper end of the linear guide 19 is arranged in the fifth support seat 18, the lower end of the linear guide 19 is arranged in the sixth support seat 22, the third high-precision motor 20 is connected with the linear guide slider 21, and the linear guide slider 21 can move on the linear guide 19. The connecting plate 14 connected with the processing module is connected with the linear guide rail slider 11, the linear guide rail slider 11 can move along the linear guide rail 7, and the second lead screw 16 and the linear guide rail 7 are arranged in parallel. The linear guide rail 7 is arranged on the cross beam 6, and the cross beam 6 and the first lead screw 5 are connected through the lead screw bearing 8. The left and right ends of the second lead screw 16 are arranged on the second support seat 9 and the fourth support seat 17 respectively.

[0064] The processing module comprises a second high-precision motor 12, a first gear 13, a first rotary joint 23, a second rotary joint 24, a spindle seat 25, a first laser displacement sensor 26, a first micro-lubrication nozzle 27, a second micro-lubrication nozzle 28, a grinding wheel 29, a second laser displacement sensor 30, a third micro-lubrication nozzle 31, a spindle 32, and a second gear 33. The first gear 13 coaxially assembled with the second high-precision motor 12 rotates to realize high-speed rotation of the grinding wheel 29 by engaging with the second gear 33. The output end of the grinding wheel is connected with the spindle 32, and the spindle is arranged in the spindle seat 25. The first laser displacement sensor 26 and the second laser displacement sensor 30 are used for synchronous measurement of surface morphology during processing. The micro-lubrication liquid enters the first micro-lubrication nozzle 27, the second micro-lubrication nozzle 28 and the third micro-lubrication nozzle 31 through the rotary joint 24 to realize friction reduction and cooling during processing. The lubricating liquid is composed of 0.1-0.5% (wt%) multi-walled carbon nanotubes and 1-5% (wt%) spherical silica colloids (diameter 20 nm) added in dimethyl silicone oil with a viscosity of 50-200 cst. The multi-walled carbon nanotubes can improve the heat conduction performance of the lubricating liquid and reduce the grinding force during grinding. The addition of spherical silica colloids can improve the material removal efficiency and has a certain sharpening effect on the grinding wheel 29. The first micro-lubrication nozzle 27, the second micro-lubrication nozzle 28 and the third micro-lubrication nozzle 31 can rotate, so that the lubricating liquid is sprayed more uniformly and sufficiently to the processing area. Further, the lubricating liquid is atomized by a piezoelectric ceramic transducer, which greatly reduces the consumption of the lubricating liquid and reduces the cost. The lubricating liquid enters the first rotary joint 23 from the micro-holes on the surface of the grinding wheel 28 based on the negative pressure effect and further enters the circulation system. Specifically, the pressure at the first rotary joint is greater than 0.5 MPa, specifically 0.5 MPa+5Q, wherein Q is the pressure at the outlet of the lubricating liquid.

[0065] The electric appliance module comprises a control cabinet 34, a pressurizing pump 37, a vacuum pump 36, a support material storage tank 35, and a laser system 38. Further, the pressurizing pump 37 is used to accelerate the injection of the phase change material, the vacuum pump is used to form a vacuum environment in the vacuum adsorption base 56, and the laser system 38 is used to generate and control laser.

[0066] The circulation module comprises a lubricating liquid tank 49, a first ultrasonic vibration head 50, a second ultrasonic vibration head 51, a third ultrasonic vibration head 52, a fourth ultrasonic vibration head 53, a fifth ultrasonic vibration head 54, a sixth ultrasonic vibration head (not shown in the figure), a cooling pipe 55, and a gradient foam; the first ultrasonic vibration head 50, the second ultrasonic vibration head 51, the third ultrasonic vibration head 52, the fourth ultrasonic vibration head 53, and the fifth ultrasonic vibration head 54 are used for fully mixing the lubricating liquid and avoiding the clogging of the gradient foam by the grinding dust; the six ultrasonic vibration heads are arranged opposite to each other; the pore size of the gradient foam decreases along with the increase of the liquid level in the lubricating liquid tank 49, and the pore size is 2mm-5mm, so that the grinding dust can be prevented from entering the lubricating liquid after circulation and causing damage to the subsequent processing surface; further, the porosity of the gradient foam is 40%-60%, so that the sufficient supply of the lubricating liquid can be ensured; further, the gradient foam is selected to have a skeleton-shaped Diamond structure, so that the filtering efficiency of the lubricating liquid can be further improved. In the embodiment, the height of the ultrasonic vibration head is the same as that of the gradient foam.

[0067] A method for in-situ grinding and polishing of a large-diameter antenna reflector sample is provided, and the steps are as follows:

[0068] S1: Place the vacuum adsorption base 56 on the moving platform 1, and place the support platform 45 on the vacuum adsorption base 56, and open the vacuum pump 36 to fix it by vacuumizing;

[0069] S2: Paste the force sensing patch according to the phyllotaxis on the back of the antenna reflector sample 43;

[0070] S3: Paste the temperature sensing patch according to the phyllotaxis on the inner surface of the support platform 45 and the back of the antenna reflector sample 43;

[0071] S4: Paste the plastic film 44 on the back of the antenna reflector sample 43;

[0072] S5: Place the antenna reflector sample 43 on the support platform 45, and make the folded lower surface of the antenna reflector sample 43 contact with the recess of the upper surface of the support platform 45, and open the vacuum pump 36 to fix it by vacuumizing;

[0073] S6: Open the pressurizing pump 37 to inject the liquid support material into the support platform through the third rotary joint 41, the fourth rotary joint 42, the fifth rotary joint 46, and the sixth rotary joint 47, and adjust the speed of injecting the support material through the third rotary joint 41, the fourth rotary joint 42, the fifth rotary joint 46, and the sixth rotary joint 47 and the switch of the coil in the heating module according to the temperature and stress sensing patches on the part and the support platform;

[0074] S7: When the liquid surface of the support material coincides with the notch on the third rotary joint 41, the fourth rotary joint 42, the fifth rotary joint 46, and the sixth rotary joint 47, stop the injection of the support material;

[0075] S8: According to the stress distribution of the surface of the antenna reflector sample 43 during the curing of the support material, adjust the switch of the heating coil to realize the low-stress clamping of the antenna reflector sample 43;

[0076] S9: Turn off the heating module, and insert the first sealing plug 39, the second sealing plug 40, and the third sealing plug 48 into the radial through hole on the side of the support platform 45;

[0077] S10: Measure the surface profile information of the antenna reflector sample 43 using the first laser displacement sensor 26 and the second laser displacement sensor 30, and reconstruct the three-dimensional model using MATLAB;

[0078] S11: Plan the polishing path of the antenna reflector sample 43 according to the reconstructed three-dimensional model information and the theoretical model;

[0079] S12: Rotate the main shaft 32, open the circulation system, spray lubricating liquid, and start polishing the antenna reflector sample 43 according to the path planned in S11. The first laser displacement sensor 26 and the second laser displacement sensor 30 measure the surface profile of the antenna reflector sample 43 and reconstruct the three-dimensional model synchronously during the polishing process;

[0080] S13: After the polishing of the antenna reflector sample 43 is completed, stop the rotation of the main shaft, close the circulation system, turn on the heating module for 20-50 min to heat to 55-65℃, maintain the temperature for 15-30 min, cool down to 15℃ for 1-1.5h, maintain the temperature for 25-50 min, repeat the above temperature rising and falling steps for 2-5 times to achieve the purpose of stress relief;

[0081] S14: Repeat S10;

[0082] S15: Repeat S10-S14 until the reconstructed three-dimensional model reaches the required surface accuracy;

[0083] S16: Turn on the heating module for 15-25 min to heat to the melting point of the support material, open the true adsorption base 56, and disassemble the antenna reflector sample 43.

[0084] After the embodiment is applied, the following technical effects can be obtained: the device uses the method of atomizing and adding nano-particles to green lubricating liquid to reduce the use amount of lubricating liquid, reduce the cost and environmental pollution; the device uses negative pressure to timely remove the lubricating liquid and the debris generated in the polishing process, avoiding the accumulation of lubricating liquid to the bottom of the antenna reflector sample; the ultrasonic vibration head is installed around the lubricating liquid storage tank to improve the efficiency of lubricating liquid circulation, and the debris adhered to the surface of nano-particles can be cleaned to improve the reusability of lubricating liquid; the traditional lubricating liquid storage tank uses foam sponge for filtration, while the gradient foam structure is used in the present application to more completely filter out the debris; the device can realize in-situ synchronous profiling measurement during the polishing process of the antenna reflector, avoiding the repeated positioning error caused by multiple clamping.

[0085] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A large aperture antenna reflector in-situ polishing device, characterized in that, It comprises a low stress clamping module, a motion module, a processing module, an electrical module and a circulation module; wherein: the low stress clamping module is used to realize the low stress flexible clamping of the antenna reflector sample, the processing module is used to realize the processing of the antenna reflector sample through the processing tool, the motion module is used to realize the spatial motion of the processing tool, the electrical module is used to provide various conditions required in the processing, and the circulation module is used to circulate and filter the micro lubricating liquid; The low stress clamping module comprises a sealing plug, a vacuum adsorption base, a support platform, a motion platform, a plastic film, a support material, a rotary joint, a heating module, a temperature sensing module, a force sensing module, a pressurizing pump, a vacuum pump and a support material storage tank; wherein, the vacuum adsorption base is connected with the vacuum pump, the support platform is installed inside the vacuum adsorption base, the vacuum adsorption base is fixed on the motion platform through vacuumizing, the vacuum adsorption base is used to fix the support platform and the part to be processed, the output end of the support material storage tank is connected with the connecting port of the outer sidewall of the support platform through the pressurizing pump and the rotary joint, the rotary joint realizes the switching of the inflow / outflow of the support material through the adjustment of the rotation angle, the heating module is used to heat the support material, realizes the stress relief treatment of the part to be processed and the disassembly of the part, the plastic film is used to avoid the direct contact between the support material and the part to be processed, the temperature sensing module is used to monitor the temperature of the support material, the force sensing module is used to monitor the stress distribution of the support material during the clamping and processing of the part to be processed, and the output of the heating coil is adjusted based on the monitoring values of the temperature sensing module and the force sensing module; The motion module comprises a motion platform and a processing tool moving device arranged on the motion platform, the motion platform can realize the Y-direction motion of the clamping device, the first lead screw and the linear guide are used to realize the Z-direction motion of the grinding wheel, and the second lead screw and the linear guide are used to realize the X-direction motion of the grinding wheel; The processing module comprises a power source, a grinding wheel, a laser displacement sensor and a plurality of micro lubricating nozzles; the high speed rotation of the grinding wheel is realized through the power output by the power source; the laser displacement sensor is used to realize the synchronous measurement of the surface topography during the processing; the micro lubricating liquid enters each micro lubricating nozzle through the rotary joint to realize the friction reduction and cooling during the processing; the lubricating liquid is composed of dimethyl silicone oil, multi-walled carbon nanotubes and spherical silica colloids, the multi-walled carbon nanotubes can improve the heat conduction performance of the lubricating liquid and reduce the grinding force during the grinding, and the addition of the spherical silica colloids can improve the material removal efficiency and has a certain sharpening effect on the grinding wheel; each micro lubricating nozzle can rotate, so that the lubricating liquid is sprayed more uniformly and sufficiently to the processing area, and the lubricating liquid enters the circulation system from the micropores on the surface of the grinding wheel based on the negative pressure effect to realize the recycling. The circulating module comprises a lubricating liquid storage tank and a plurality of ultrasonic vibration heads, cooling pipes and gradient foams arranged on the tank; the ultrasonic vibration heads are used to mix the lubricating liquid evenly and avoid the clogging of the gradient foams by the grinding dust; the pore size of the gradient foams decreases along with the increase of the liquid level in the lubricating liquid storage tank, and the pore size is 2mm-5mm, and the porosity of the gradient foams is 40%-60%; The shape of the support platform is designed according to the shape of the part to be machined, and the equal stress clamping is realized. The support platform is provided with a through hole in the axial direction, which serves as a vacuum suction channel for vacuum suction of the part to be machined. The side of the support platform has a radial through hole for supporting the overflow of the gas in the inner cavity formed by the support platform and the plastic film when the support material is filled. The sealing plug is used to block the radial through hole on the side of the support platform when the support material is added, so as to avoid the oxidation of the multi-walled carbon nanotubes by oxygen during the post-processing of the part to be machined. The sealing plug is in the shape of a truncated cone, and the inner surface of the support platform has a heat insulation coating, which is selected from aerogel nano thermal insulation paint. The heating module is composed of a plurality of coils, which include strip-shaped heating modules and ring-shaped heating modules. The strip-shaped heating modules are installed on the inner side wall of the support platform, and the ring-shaped heating modules are installed on the inner bottom surface of the support platform in a ring shape. The coils are single units that can be individually controlled to turn on and off, thereby achieving precise control of the heating area. The on-off of the coils is controlled by the comprehensive feedback of temperature sensing patches and force sensing patches, thereby achieving low-stress clamping of the part to be machined.

2. The in-situ polishing device for large aperture antenna reflector according to claim 1, characterized in that, The temperature sensing module comprises a first temperature sensing patch group, a second temperature sensing patch group and a third temperature sensing patch group. The first temperature sensing patch group is attached to the back of the part to be machined, and the first and second temperature sensing patch groups are attached to the inner bottom surface and the inner side surface of the support platform, respectively. The first, second and third temperature sensing patch groups are used to detect the temperature distribution of the support material during the filling of the support material into the support platform, the post-stress treatment and the temperature distribution during the machining process. The first and third temperature sensing patch groups are arranged according to the phyllotaxis rule, and the distance between two adjacent temperature sensing patches is a predetermined value. The force sensing module comprises a first force sensing patch group and a second force sensing patch group. The first force sensing patch group is arranged on the support platform at the flange of the part to be machined. The second force sensing patch group is attached to the back of the part to be machined, and is used to detect the stress distribution during clamping and machining. The force sensing patches are embedded in the gaps between the temperature sensing patches.

3. The in-situ polishing device for large aperture antenna reflector according to claim 1, characterized in that, One side of the plastic film is provided with a heat-resistant adhesive that does not react with the part to be machined, which is used to perfectly adhere the plastic film to the lower surface of the part to be machined. The other side of the plastic film has a plurality of protrusions.

4. The in-situ polishing device for large aperture antenna reflector according to claim 1, characterized in that, The support material is a low-melting-point phase change material, which comprises paraffin with multi-walled carbon nanotubes.

5. A method for in-situ grinding and polishing of a large aperture antenna reflector sample, characterized in that, The large-diameter antenna reflector in-situ polishing device is used, and the following steps are included: S1: Place the vacuum adsorption base on the moving platform, and place the support platform on the vacuum adsorption base, open the vacuum pump to vacuumize and fix it; S2: Paste the force sensing patch on the back of the antenna reflector sample according to the phyllotaxis; S3: Paste the temperature sensing patch on the inner surface of the support platform and the back of the antenna reflector sample according to the phyllotaxis; S4: Paste the plastic film on the back of the antenna reflector sample; S5: Place the antenna reflector sample on the support platform, and make the antenna reflector sample flange lower surface contact with the recess on the upper surface of the support platform, open the vacuum pump to vacuumize and fix it; S6: Open the pressurizing pump to inject the liquid support material into the support platform through the rotary joint, adjust the speed of the rotary joint injection and the switch of the coil in the heating module according to the temperature and stress sensing patch on the part and the support platform; S7: When the liquid surface of the support material coincides with the notch on the rotary joint, stop the injection of the support material; S8: According to the stress distribution on the surface of the antenna reflector sample during the curing process of the support material, adjust the switch of the heating coil to realize the low stress clamping of the antenna reflector sample; S9: Turn off the heating module, and plug the sealing plug into the radial through hole on the side of the support platform; S10: Measure the surface profile information of the antenna reflector sample by using the laser displacement sensor, and reconstruct the three-dimensional model; S11: According to the reconstructed three-dimensional model information and the theoretical model, plan the grinding and polishing path of the antenna reflector sample; S12: Rotate the main shaft, open the circulating system, spray lubricating liquid, and start grinding and polishing the antenna reflector sample according to the path planned in S11, and the laser displacement sensor measures the surface profile of the antenna reflector sample and reconstructs the three-dimensional model synchronously during the process; S13: After the antenna reflector sample is processed, stop the rotation of the main shaft, turn off the circulating system, turn on the heating module for 20~50 min to heat to 55~65 ℃, keep warm for 15~30 min, cool down to 15 ℃ for 1~1.5 h, keep warm for 25~50 min, repeat the above heating and cooling steps for 2~5 times to achieve the purpose of stress relief; S14: Repeat S10; S15: Repeat S10~S14 until the reconstructed three-dimensional model reaches the required surface accuracy; S16: Turn on the heating module for 15~25 min to heat to the melting point of the support material, open the vacuum adsorption base, and disassemble the antenna reflector sample.

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