A flexible fairing polishing airbag and a fairing polishing method thereof

Abstract

The present application provides a flexible fairing polishing air bag and a fairing polishing method thereof, comprising an air bag tool head, the air bag tool head has flexibility, the air bag tool head comprises a plurality of air bags, the thickness of the plurality of air bags is different, and the Shore hardness of the plurality of air bags is also different.The present application provides an air bag tool capable of making the air bag polishing machine generate a U-shaped removal function, which solves the problem that the air bag polishing machine is difficult to complete the fairing polishing process, reduces the cost of the production line, improves the utilization rate of the machine tool, and improves the polishing precision that can be reached by the machine tool; a new air bag clamping mode is also provided, which improves the coaxiality and repeated installation precision of the existing air bag polishing tool and spindle, and simplifies the installation mode of the air bag; the fairing polishing process method of the present application improves the application of air bag polishing in fairing polishing, and provides a new idea for subsequent large-aperture aspheric surface machining routes.

Description

Technical Field

[0001] This invention belongs to the field of polishing technology, specifically relating to a flexible smooth polishing airbag and its smooth polishing method. Background Technology

[0002] In the field of polishing technology, airbag polishing has become an important supporting technology for optical engineering after decades of development. Airbag polishing uses flexible spherical airbags with different curvatures as polishing tools and proposes a "precession polishing" process. It has advantages such as good conformity with the workpiece surface, non-zero rotation center speed, less risk of workpiece damage, high polishing efficiency, and easy generation of Gaussian removal functions.

[0003] Chinese invention patent CN102975106B discloses a clamping method for an airbag polishing tool, which connects the spindle to the airbag tool head via a hydraulic tensioning sleeve. However, this method makes it difficult to guarantee the coaxiality of the airbag tool head and the spindle, and the disassembly and installation process is cumbersome. Furthermore, airbag polishing technology struggles to achieve a smooth polishing process due to its difficulty in generating a U-shaped removal function. Smooth polishing refers to reducing the mid-to-high frequency errors of aspherical optical elements without compromising existing low-frequency errors, ensuring that the mid-to-high frequency errors of the aspherical optical elements meet the requirements of the optical system.

[0004] Smoothing polishing is the final step in correction polishing. Currently, smoothing polishing is mainly completed by CCOS small grinding head polishing. CCOS small grinding head polishing technology uses a polishing disc much smaller than the workpiece, under computer control, to move on the surface of the optical part along a specific path and speed. By controlling parameters such as the dwell time and processing pressure in each area, the amount of material removed from the part can be precisely controlled to correct errors and improve accuracy.

[0005] Chinese invention patent CN102744663B discloses a CCOS small grinding head device composed of an eccentric rotary mechanism and a translational rotary conversion mechanism, but its equipment structure and wiring are complex, the flexible shaft transmission is unstable, the transmission rigidity is poor, and the polishing efficiency is low. Compared with the self-rotating small grinding head, the male-rotating small grinding head has advantages such as a non-zero center point speed and a more complex trajectory.

[0006] If smooth polishing can be achieved on an airbag polishing machine, the efficiency and accuracy of smooth polishing can be improved. Therefore, an airbag tool that can generate a U-shaped removal function on the polishing machine and a new clamping method are needed. Combining the advantages of airbag polishing machines and CCOS small grinding heads can improve the fit between the tool and the workpiece, the polishing efficiency, the utilization rate of the equipment, and the accuracy and convenience of tool installation.

[0007] In view of this, it is very meaningful to propose a flexible smooth polishing airbag and its smooth polishing method. Summary of the Invention

[0008] This invention provides a flexible smooth polishing airbag and a smooth polishing method thereof to solve the above-mentioned technical defects.

[0009] In a first aspect, the present invention proposes a flexible smooth polishing airbag, including an airbag tool head, the airbag tool head being flexible, the airbag tool head comprising several rings of airbags, the thickness of the several rings of airbags being different, and the Shore hardness of the several rings of airbags also being different.

[0010] Preferably, the number of airbags is set to eight, and the eight airbags include five different Shore hardnesses.

[0011] More preferably, the outer diameters of the eight airbags increase from small to large as follows: the 1st to the 8th airbag; the 8th airbag has a Shore hardness of approximately 50 and a thickness of approximately 1 mm; the 3rd and 5th airbags have a Shore hardness of approximately 60 and a thickness of approximately 1 mm; the 2nd and 6th airbags have a Shore hardness of approximately 75 and a thickness of approximately 1.5 mm; the 1st and 7th airbags have a Shore hardness of approximately 90 and a thickness of approximately 1.5 mm; and the 4th airbag has a Shore hardness of approximately 95 and a thickness of approximately 3 mm.

[0012] More preferably, the eight airbags are bonded together in pairs with a flexible adhesive.

[0013] Preferably, the airbag tool head is machined into a spherical crown shape using a lathe.

[0014] Preferably, the airbag is made of rubber, including silicone rubber, butyl rubber, and natural rubber.

[0015] Preferably, the device also includes a clamping assembly comprising a base made of 45 steel and a tool holder, the base being fixed to the tool holder by bolts.

[0016] More preferably, the base and the bottom of the handle have a 0.2mm gap, the top of the base and the handle have a 0.1mm gap, and the inner conical surface of the handle mates with the outer conical surface of the base.

[0017] Secondly, embodiments of the present invention provide a smoothing and polishing method, comprising the following steps:

[0018] S1: Detect surface distribution error using a laser interferometer;

[0019] S2: Select a suitable removal function from the removal function library obtained from previous process experiments, and determine the airbag radius, polishing pad type, polishing fluid concentration, abrasive size, inflation pressure, precession angle and downward pressure.

[0020] S3: Correlate the surface shape error with the feed rate, and then solve the dwell time matrix based on the relationship between the feed rate and the dwell time;

[0021] S4: Set process parameters, including setting polishing trajectory, spindle speed, feed rate, number of trajectory points, and spacing between trajectory points;

[0022] S5: Input the process parameters into the CAM software and import the output CNC code into the CNC system;

[0023] S6: Perform airbag smoothing polishing, which includes cleaning the workpiece, determining the workpiece surface height and the workpiece center point, and performing smoothing polishing in roughing, semi-finishing and finishing stages.

[0024] Furthermore, the cleaning and processing details in S6 specifically include:

[0025] S6.1: Clean the workpiece in an ultrasonic bath in anhydrous ethanol for about 0.5 hours, and then place it in a clean room to dry for 1 hour to remove impurities such as polishing powder dust remaining on the surface.

[0026] S6.2: Coarse polishing, using cerium oxide polishing slurry, with polishing particle size of 1.5~2μm, and polishing pad is made of polyurethane material with added cerium oxide additives, reducing the depth of the surface damage layer to within submicron, and controlling the downward pressure and inflation pressure to keep the pressure between the workpiece and the airbag head at around 20N.

[0027] S6.3: Clean the workpiece in an ultrasonic bath in anhydrous ethanol for about 1 hour, and then place it in a clean room to dry for 2 hours to remove impurities such as polishing powder and dust remaining on the surface.

[0028] S6.4: Semi-finish polishing, using cerium oxide polishing slurry, polishing particle diameter not greater than 1μm, polishing pad is made of damping cloth, control the downward pressure and inflation pressure to keep the pressure between the workpiece and the airbag head at about 15N.

[0029] S6.5: Clean the workpiece in an ultrasonic bath in anhydrous ethanol for about 1 hour, then place it in a clean room to dry for 2 hours before use to remove impurities such as polishing powder and dust from the surface.

[0030] S6.6: Fine polishing, controlling the surface finish of the surface scratches and sand holes remaining from S6.5. Silica polishing slurry is used, the polishing particle diameter is no more than 50nm, and optical asphalt polishing pads are selected. The pressure and inflation pressure are controlled to keep the pressure between the workpiece and the airbag head at around 5N, and the spindle speed is around 100 rpm.

[0031] Compared with the prior art, the beneficial results of the present invention are as follows:

[0032] (1) This invention provides an airbag tool that enables an airbag polishing machine to produce a U-shaped removal function. This tool solves the problem that airbag polishing machines are difficult to complete the smoothing process, reduces the cost of the production line, improves the utilization rate of the machine tool, and improves the polishing accuracy that the machine tool can achieve. It also provides a new airbag clamping method, which improves the coaxiality and repeatability of the existing airbag polishing tool and spindle while simplifying the airbag installation method. The smoothing polishing process method of this invention improves the application of airbag polishing in smoothing polishing and provides a new idea for the subsequent large-diameter aspherical surface processing route.

[0033] (2) Flexible multi-ring unequal thickness airbags enable airbag polishing machines to achieve smooth processing, reduce production line costs, and improve equipment utilization. Flexible multi-ring unequal thickness airbags have different specifications, and the largest airbag radius can currently reach R320, which greatly improves the efficiency of smooth polishing. The flexible multi-ring unequal thickness airbags are spherical, which fits better with the workpiece and improves the surface quality of the workpiece. The installation method of the airbags has been further optimized, improving the installation accuracy and consistency of repeated installation of the existing airbag polishing tools, and simplifying the installation steps, making the installation of the airbag tool head more convenient. Attached Figure Description

[0034] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the invention. Other embodiments and many anticipated advantages of the embodiments will be readily recognized as they become better understood through reference to the following detailed description. Elements in the drawings are not necessarily to scale. The same reference numerals refer to corresponding similar parts.

[0035] Figure 1 This is a front view of the flexible smoothing polishing tool head in the flexible smoothing polishing airbag according to an embodiment of the present invention;

[0036] Figure 2 This is a cross-sectional view of the flexible smoothing polishing tool head in the flexible smoothing polishing airbag according to an embodiment of the present invention;

[0037] Figure 3 This is a bottom view of the flexible smoothing polishing tool head in the flexible smoothing polishing airbag according to an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the airbag compression in the flexible smoothing polishing airbag according to an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the flexible smoothing polishing precession mechanism in the flexible smoothing polishing airbag according to an embodiment of the present invention;

[0040] Figure 6This is a schematic diagram of the airbag polishing removal function in the flexible smooth polishing airbag according to an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of the removal function of the flexible smoothing polishing tool in the flexible smoothing polishing airbag according to an embodiment of the present invention;

[0042] Figure 8 This is a schematic diagram of the smoothing polishing step in the smoothing polishing method of an embodiment of the present invention.

[0043] Reference numerals: 1. Tool holder; 2. Air bladder; 3. Base; 4. 8th ring of rubber; 5. 7th ring of rubber; 6. 6th ring of rubber; 7. 5th ring of rubber; 8. 4th ring of rubber; 9. 3rd ring of rubber; 10. 2nd ring of rubber; 11. 1st ring of rubber; 12. Spindle; 13. Workpiece. Detailed Implementation

[0044] In the following detailed description, reference is made to the accompanying drawings, which form part of the detailed description and are illustrated by specific illustrative embodiments in which the invention may be practiced. In this regard, directional terms such as “top,” “bottom,” “left,” “right,” “up,” “down,” etc., are used with reference to the orientation of the described figures. Because components of the embodiments can be positioned in several different orientations, directional terms are used for illustrative purposes and are by no means limiting. It should be understood that other embodiments may be utilized or logical changes may be made without departing from the scope of the invention. Therefore, the following detailed description should not be taken in a limiting sense, and the scope of the invention is defined by the appended claims.

[0045] This invention provides an airbag 2 tool that can generate a U-shaped removal function on an airbag polishing machine, which not only realizes the function of a CCOS small grinding head on the airbag 2 polishing machine, but also improves the fit with the workpiece 13 and the polishing efficiency; it also provides a clamping method with higher installation accuracy, repeatability and consistency and convenience; and it provides a method for achieving smoothing on the airbag 2 polishing machine.

[0046] In a first aspect, embodiments of the present invention disclose a flexible, smooth polishing airbag 2, such as... Figure 1 As shown, the tool head includes an airbag 2, which comprises several rings of airbag 2. The airbag 2 is flexible, and the thickness and Shore hardness of the several rings of airbag 2 are not uniform.

[0047] Specifically, this invention discloses a flexible multi-coil unequal thickness airbag 2 tool head, such as... Figure 2 and Figure 3 As shown, it includes 8 rings of rubber, which include 5 different Shore hardness rubbers. The rubber can be silicone rubber, butyl rubber, natural rubber, etc. In other embodiments, the material of the airbag can also be selected as polyurethane, etc.

[0048] Reference Figure 4 and Figure 6 To ensure a U-shaped removal function during the compression process, the rubber used needs to be softer where the compression distance is greater to generate less pressure, and the rubber used needs to be harder where the compression distance is smaller to generate more pressure. Figure 7 As shown, the pressure is made uniform throughout the polishing rod to obtain a U-shaped removal function.

[0049] Specifically, such as Figure 2 and Figure 3 As shown, during polishing, the removal function center is located in the 8th ring. The Shore hardness of rubber 4 in the 8th ring is approximately 50, and its thickness is approximately 1mm; the Shore hardness of rubber 7 in the 3rd and 5th rings is approximately 60, and its thickness is approximately 1mm; the Shore hardness of rubber 6 in the 2nd and 6th rings is approximately 75, and its thickness is approximately 1.5mm; the Shore hardness of rubber 5 in the 1st and 7th rings is approximately 90, and its thickness is approximately 1.5mm; the Shore hardness of rubber 8 in the 4th ring is approximately 95, and its thickness is approximately 3mm. (Refer to...) Figure 5 This achieves the effect of equal pressure in all parts when the airbag 2 contacts the workpiece 13.

[0050] Furthermore, the rubber rings are bonded together with adhesive. The tool head of the airbag 2 is spherical, and its outer surface is machined on a lathe. The flexible multi-ring airbag 2 with unequal thickness is bonded to the steel base 3 with flexible adhesive. In this embodiment, Loctite adhesive is preferred.

[0051] This invention provides an airbag 2 tool that enables the airbag 2 polishing machine to generate a U-shaped removal function. This tool solves the problem that the airbag 2 polishing machine is difficult to complete the smoothing process, reduces the cost of the production line, improves the utilization rate of the machine tool, and improves the polishing accuracy that the machine tool can achieve.

[0052] Furthermore, such as Figure 2 and Figure 5 As shown, the present invention also discloses a clamping method with higher installation accuracy, consistency of repeated installation and convenience, including an airbag 2 base 3 made of 45 steel and an airbag handle 1 made of 45 steel. To reduce the machining difficulty, a 0.2mm gap is left at the bottom of the base 3 and the handle 1, and a 0.1mm gap is left at the top of the base 3 and the handle 1. The steel base 3 is fixed to the handle 1 with bolts. During assembly, the inner conical surface of the handle 1 mates with the outer conical surface of the base 3, thereby achieving higher coaxiality.

[0053] The present invention also provides a novel airbag clamping method, which improves the coaxiality and repeatability of the existing airbag 2 polishing tool and spindle 12 while simplifying the installation method of airbag 2.

[0054] Secondly, embodiments of the present invention also disclose a smoothing and polishing method, such as... Figure 8 As shown, it includes the following steps:

[0055] S1: Detect surface distribution error using a laser interferometer;

[0056] S2: Select a suitable removal function from the removal function library obtained from previous process experiments, and determine the radius of airbag 2, polishing pad type, polishing fluid concentration, abrasive size, inflation pressure, precession angle and downward pressure.

[0057] S3: Correlate the surface shape error with the feed rate, and then solve the dwell time matrix based on the relationship between the feed rate and the dwell time;

[0058] S4: Set process parameters, including setting polishing trajectory, spindle speed 12, feed rate, number of trajectory points, and spacing between trajectory points;

[0059] S5: Input the process parameters into the CAM software and import the output CNC code into the CNC system;

[0060] S6: Perform smooth polishing with airbag 2, which includes cleaning workpiece 13, determining the surface height of workpiece 13 and determining the center point of workpiece 13, and performing smooth polishing in roughing, semi-finishing and finishing stages.

[0061] Furthermore, the cleaning and processing details in S6 specifically include:

[0062] S6.1: Clean the workpiece 13 in an ultrasonic bath in anhydrous ethanol for about 0.5 hours, and then place it in a clean room to dry for 1 hour to remove impurities such as polishing powder dust remaining on the surface.

[0063] S6.2: Coarse polishing, using cerium oxide polishing slurry, with polishing particle size of 1.5~2μm, and polishing pad is made of polyurethane material with added cerium oxide additives, reducing the depth of the surface damage layer to within submicron, and controlling the downward pressure and inflation pressure to keep the pressure between workpiece 13 and airbag 2 head at around 20N.

[0064] S6.3: Clean the workpiece 13 in an ultrasonic bath in anhydrous ethanol for about 1 hour, and then place it in a clean room to dry for 2 hours to remove impurities such as polishing powder dust remaining on the surface.

[0065] S6.4: Semi-finish polishing, using cerium oxide polishing liquid, polishing particle diameter not greater than 1μm, polishing pad is made of damping cloth, control the downward pressure and inflation pressure to keep the pressure between workpiece 13 and airbag 2 head at about 15N.

[0066] S6.5: Clean the workpiece 13 in an anhydrous ethanol in an ultrasonic bath for about 1 hour, then place it in a clean room to dry for 2 hours before use to remove impurities such as polishing powder and dust from the surface.

[0067] S6.6: Fine polishing, controlling the surface finish of the surface scratches and sand holes remaining from S6.5. Silica polishing slurry is used, the polishing particle diameter is no more than 50nm, and optical asphalt polishing pads are selected. The pressure and inflation pressure are controlled so that the pressure between workpiece 13 and airbag 2 is about 5N, and the spindle speed is about 100 rpm.

[0068] The smooth polishing process of this invention improves the application of airbag 2 polishing in smooth polishing and provides a new approach for subsequent large-diameter aspherical surface processing.

[0069] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A flexible, smooth, polished airbag, characterized in that, The tool includes an airbag tool head, which is flexible and comprises eight airbags of varying thicknesses and Shore A hardnesses. The eight airbags represent five different Shore A hardnesses. The tool head is spherical in shape. The outer diameters of the eight airbags, from smallest to largest, are as follows: the 8th airbag has a Shore A hardness of 50 and a thickness of 1 mm; the 3rd and 5th airbags have a Shore A hardness of 60 and a thickness of 1 mm; the 2nd and 6th airbags have a Shore A hardness of 75 and a thickness of 1.5 mm; the 1st and 7th airbags have a Shore A hardness of 90 and a thickness of 1.5 mm; and the 4th airbag has a Shore A hardness of 95 and a thickness of 3 mm.

2. The flexible smooth polishing airbag according to claim 1, characterized in that, The airbags described in the eight rings are bonded together in pairs with flexible adhesive.

3. The flexible smooth polishing airbag according to claim 1, characterized in that, The airbag tool head is machined into a spherical crown shape using a lathe.

4. The flexible smooth polishing airbag according to claim 1, characterized in that, The airbag is made of rubber, including silicone rubber, butyl rubber, and natural rubber.

5. The flexible smooth polishing airbag according to claim 1, characterized in that, It also includes a clamping assembly comprising a base made of 45 steel and a tool holder, the base being fixed to the tool holder by bolts.

6. The flexible smooth polishing airbag according to claim 5, characterized in that, The base and the bottom of the handle have a 0.2mm gap, the top of the base and the handle have a 0.1mm gap, and the inner conical surface of the handle mates with the outer conical surface of the base.

7. A smoothing and polishing method, characterized in that, The flexible smoothing and polishing airbag as described in any one of claims 1-6 includes the following steps: S1: Detect surface distribution error using a laser interferometer; S2: Select a suitable removal function from the removal function library obtained from previous process experiments, and determine the airbag radius, polishing pad type, polishing fluid concentration, abrasive size, inflation pressure, precession angle and downward pressure. S3: Correlate the surface shape error with the feed rate, and then solve the dwell time matrix based on the relationship between the feed rate and the dwell time; S4: Set process parameters, including setting polishing trajectory, spindle speed, feed rate, number of trajectory points, and spacing between trajectory points; S5: Input the process parameters into the CAM software and import the output CNC code into the CNC system; S6: Perform airbag smoothing polishing, which includes cleaning the workpiece, determining the workpiece surface height and the workpiece center point, and performing smoothing polishing in roughing, semi-finishing and finishing stages.

8. The smoothing and polishing method according to claim 7, characterized in that, The cleaning and processing details in S6 also include: S6.1: Clean the workpiece in an ultrasonic bath in anhydrous ethanol for 0.5 hours, and then place it in a clean room to dry for 1 hour to remove impurities such as polishing powder dust remaining on the surface. S6.2: Coarse polishing, using cerium oxide polishing slurry, with polishing particle size of 1.5~2μm, and polishing pad is made of polyurethane material with added cerium oxide additives, reducing the depth of the surface damage layer to within submicron, and controlling the downward pressure and inflation pressure to make the pressure between the workpiece and the airbag head 20N. S6.3: Clean the workpiece in an ultrasonic bath in anhydrous ethanol for 1 hour, and then place it in a clean room to dry for 2 hours to remove impurities such as polishing powder dust remaining on the surface. S6.4: Semi-finish polishing, using cerium oxide polishing slurry, polishing particle diameter not greater than 1μm, polishing pad is made of damping cloth, control the downward pressure and inflation pressure to make the pressure between the workpiece and the airbag head 15N; S6.5: Clean the workpiece in an ultrasonic bath in anhydrous ethanol for 1 hour, then place it in a clean room to dry for 2 hours before use to remove impurities such as polishing powder and dust from the surface. S6.6: Fine polishing, controlling the surface finish of the surface scratches and sand holes remaining from S6.

5. Silica polishing slurry is used, the polishing particle diameter is no more than 50nm, and optical asphalt polishing pads are selected. The pressure and inflation pressure are controlled to make the pressure between the workpiece and the airbag head 5N.

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