Method for manufacturing a more than half spherical aluminum ball shell

Abstract

The application provides a manufacturing method of a hemi-aluminum spherical shell, which comprises the following steps: firstly, a hemi-core shaft ball is obtained through super-precision turning, so as to ensure the size precision and roughness of the outer spherical surface; secondly, a special fixture is manufactured through precise turning, milling and super-precision turning; then, the hemi-core shaft ball is assembled on the conical surface of the special fixture through negative pressure adsorption and adhesive fixation; the hemi-aluminum spherical shell is obtained through super-precision turning; and finally, the inner and outer stoppers are processed and assembled to form a complete spherical shell to load specific substances. The manufacturing method of the hemi-aluminum spherical shell can obtain a high-precision hemi-aluminum spherical shell, which has better size precision consistency and higher wall thickness uniformity than the hemi-aluminum spherical shell manufactured by using a traditional mold, and the wall thickness uniformity of the hemi-aluminum spherical shell is better than 3 mu m, so that the yield can be improved and the cost can be reduced.

Description

A method for manufacturing a hemispherical aluminum spherical shell Technical Field

[0001] This invention relates to the field of precision micro-parts manufacturing, and specifically to a method for manufacturing a hemispherical aluminum spherical shell. Background Technology

[0002] In fields such as laser fusion and biomedicine, tiny spherical shell components are widely used to contain specific substances such as gases, liquids, and solids. The main method for manufacturing these tiny spherical shell components is to fabricate a semi-spherical shell and then assemble it.

[0003] The patent number "CN201921977177.1" entitled "A Vacuum Adsorption Fixture for Hemispherical Shells in Machining" provides a fixture for manufacturing hemispherical shells. However, this fixture automatically positions the shell by fitting the center of the sphere together during use. Since the preparation of hemispherical shells uses a mandrel rather than a sphere, this fixture is not suitable for manufacturing hemispherical shells.

[0004] Patent number "CN201410116159.X" entitled "A Method for Manufacturing a Thin-Walled Metal Hemispherical Shell with a Stop" provides a method for manufacturing a hemispherical shell with an outer diameter of φ1mm to φ10mm and a wall thickness of 0.1mm to 0.2mm. The method involves bonding a polished solid metal sphere to the inner hemispherical surface of a fixture using conductive adhesive, machining the inner hemispherical surface using electrical discharge machining, and performing point grinding on thicker areas using small hemispherical surface grinding. The consistency of the metal hemispherical shell wall thickness is repeatedly checked and grinding is repeated until the requirements are met. However, this method is too cumbersome. Repeated grinding not only increases processing costs but also carries the risk of hemispherical shell deformation. Furthermore, the inner hemispherical surface of the fixture has the same diameter as the solid metal sphere, requiring high precision during manufacturing. The spherical fixture is also difficult to operate when fixing the solid metal sphere, which is prone to eccentricity. Therefore, the fixing effect during bonding is relatively poor, and there will be some error during bonding, affecting the processing accuracy. Furthermore, based on the traditional mold-based manufacturing method, the mold and the spherical shell are bonded together with adhesive. The thickness of the adhesive layer cannot be precisely controlled, resulting in poor uniformity of the spherical shell wall thickness and an inability to effectively guarantee product quality. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for manufacturing a hemispherical aluminum spherical shell, achieving the invention objective of manufacturing a hemispherical aluminum spherical shell with good wall thickness uniformity, high yield, and low processing cost.

[0006] To solve the above technical problems, the present invention adopts the following technical solution:

[0007] A method for manufacturing a hemispherical aluminum spherical shell includes the following steps:

[0008] a. A solid aluminum column is machined into a hemispherical mandrel ball using ultra-precision turning;

[0009] b. Machining the solid copper core shaft into the required special fixtures through precision turning, milling, and ultra-precision turning;

[0010] c. Assemble the hemispherical mandrel ball onto the special fixture, and at the same time use a negative pressure pump to draw negative pressure to fix the hemispherical mandrel ball, eliminate the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture, eliminate external factors that affect the uniformity of the wall thickness of the hemispherical aluminum shell, and then fill the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture with 502 glue.

[0011] d. After the 502 glue has cured and formed a 502 glue layer, remove the negative pressure pump and machine the hemispherical mandrel ball through ultra-precision turning to form the inner spherical surface of the hemispherical aluminum shell, thus obtaining the hemispherical aluminum shell to be processed.

[0012] e. Remove the 502 adhesive layer between the hemispherical aluminum shell to be treated and the conical surface of the special fixture by soaking it in acetone. Clean the hemispherical aluminum shell to be treated, and let it dry to obtain the desired hemispherical aluminum shell.

[0013] Preferably, the hemispherical mandrel is designed as a combination of a sphere and a shaft.

[0014] Preferably, the special fixture includes a special fixture column, a special fixture conical surface, a negative pressure channel, and a negative pressure pump; the negative pressure pump is detachable.

[0015] Furthermore, the cone angle of the special fixture's conical surface is 80°; the cone height is 0.35mm to 0.5mm, and it is consistent with the radius of the sphere of the hemispherical mandrel; the diameter of the center hole is 0.35mm to 0.4mm.

[0016] The cone height refers to the distance between the port and the center hole of the cone surface of the special fixture.

[0017] Furthermore, one end of the negative pressure channel is connected to a negative pressure pump, and the other end is connected to the center hole of the conical surface of a special fixture.

[0018] By utilizing the negative pressure channel and using a negative pressure pump to draw negative pressure, the hemispherical mandrel ball can be tightly adsorbed and fixed on the conical surface of the special fixture, thereby eliminating the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture, making the machining more precise.

[0019] Furthermore, the negative pressure value of the negative pressure pump is 0.8 atm to 0.9 atm.

[0020] Furthermore, the wall thickness h of the hemispherical aluminum shell ranges from 0.06 mm to 0.08 mm.

[0021] Furthermore, the inner diameter of the hemispherical aluminum shell The range is

[0022] Furthermore, the height L of the hemispherical aluminum shell cap ranges from 0.43 mm to 0.6 mm.

[0023] Furthermore, the turning process parameters in steps (a), (b), and (d) are as follows: the rotational speed n ranges from 1800 r / min to 3000 r / min, the depth of cut ap ranges from 0.5 μm to 5.5 μm, and the feed rate f ranges from 0.001 mm / r to 0.005 mm / r.

[0024] Furthermore, the dimensional deviations of the outer spherical surface of the hemispherical mandrel, the conical surface of the special fixture, the outer circular surface of the special fixture column, and the inner spherical surface of the hemispherical aluminum shell obtained by turning in steps (a), (b), and (d) are all less than 1.5 μm, and the surface roughness is less than Ra20 nm.

[0025] The present invention also provides an application of a hemispherical aluminum shell manufactured based on the aforementioned hemispherical aluminum shell manufacturing method. The hemispherical aluminum shell, after processing the inner and outer stops and then assembling into a complete aluminum shell, can be used for loading specific substances such as gases, liquids, solids, foams, and powders.

[0026] Furthermore, this hemispherical aluminum shell was applied in inertial confinement experiments.

[0027] The hemispherical aluminum shell manufactured using the manufacturing method of this invention has better dimensional consistency and wall thickness uniformity compared to the traditional bonding manufacturing method. The wall thickness uniformity is better than 3μm, which can increase the yield and reduce the cost.

[0028] By adopting the above technical solution, the technical effect achieved by this invention is as follows:

[0029] 1. This invention achieves high-precision fabrication of hemispherical aluminum shells using a specialized fixture, and ensures uniform wall thickness by eliminating the influence of the adhesive layer on the coaxiality of the shell through a conical negative pressure method. The key to this invention is eliminating the influence of the adhesive layer and human factors to achieve high-precision hemispherical aluminum shells with good wall thickness uniformity.

[0030] 2. The present invention designs the special fixture as a conical surface, which enables precise positioning of the hemispherical mandrel ball. Furthermore, the accuracy of the conical fixture has no impact on the processing of the hemispherical aluminum shell, thereby reducing processing costs and improving the product yield.

[0031] 3. Since the hemispherical aluminum shell is very small, it is not easy to process it as a sphere. Therefore, the hemispherical mandrel ball assembly shown in Figure 3 is used for processing in a special fixture, which facilitates operation and assembly.

[0032] 4. Specialized Fixture Design: The fixture features a specialized column, a specialized conical surface, a negative pressure channel, and a negative pressure pump. Utilizing the negative pressure channel, the negative pressure pump draws negative pressure, causing the hemispherical mandrel to adhere tightly to the specialized fixture conical surface. This eliminates the gap at the tangent point between the hemispherical mandrel and the conical surface. 502 glue is then filled into the gap at the tangent point to eliminate the influence of glue thickness on the machining accuracy of the hemispherical mandrel, improving the yield rate. The negative pressure pump is detachable; after fixing the hemispherical mandrel with 502 glue, the pump can be removed for easier processing.

[0033] 4. The hemispherical aluminum spherical shell manufactured using the manufacturing method of the present invention has good dimensional consistency and wall thickness uniformity, high precision, inner spherical surface dimensional deviation of less than 0.5μm, surface roughness of less than Ra10nm, wall thickness uniformity of less than 3μm, and a yield rate of 100%. Attached Figure Description

[0034] Figure 1 is a process flow diagram of the method for manufacturing the hemispherical aluminum spherical shell of the present invention;

[0035] Figure 2 is a cross-sectional view of the hemispherical aluminum spherical shell structure manufactured by the hemispherical aluminum spherical shell manufacturing method of the present invention.

[0036] Figure 3 is a cross-sectional view of the structure of the hemispherical mandrel ball in the embodiment;

[0037] Figure 4 is a structural cross-sectional view of the special fixture in the embodiment;

[0038] Figure 5 is an assembly diagram of the hemispherical mandrel ball in step c of the embodiment;

[0039] Figure 6 shows the 502 glue fixing diagram of the hemispherical mandrel ball in step d of the embodiment;

[0040] Figure 7 is a cross-sectional view of the structure after removing the negative pressure pump in step d of the embodiment;

[0041] Figure 8 is a cross-sectional view of the structure of the hemispherical aluminum shell to be processed in step d of the embodiment. Detailed Implementation

[0042] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0043] Example 1

[0044] This embodiment is used to manufacture a material with a wall thickness of 0.06 mm and an inner diameter of [missing information]. A hemispherical aluminum spherical shell with a crown height of 0.43 mm (greater than the inner radius of the spherical shell by 0.35 mm).

[0045] The manufacturing method of this embodiment includes the following steps:

[0046] a. Material preparation: Solid aluminum cylinders are machined into hemispherical mandrels using ultra-precision turning. The machining parameters are: rotation speed (n) 2600 r / min, depth of cut (ap) 2.5 μm, and feed rate (f) 0.002 mm / r. The dimensional deviation of the hemispherical mandrel is measured to be 0.5 μm using a microscope, and the surface roughness of the hemispherical mandrel is measured to be Ra 16 nm using a white light interferometer, which meets the technical requirements for hemispherical mandrels.

[0047] b. The solid copper core shaft is machined into the required special fixture through precision turning, milling, and ultra-precision turning. The machining parameters for precision turning are: rotational speed (n) 1800 r / min, depth of cut (ap) 5.5 μm, feed rate (f) 0.0015 mm / r; the machining parameters for milling are: rotational speed (n) 8600 r / min, depth of cut (ap) 20 μm, feed rate (f) 300 mm / min; and the machining parameters for ultra-precision turning are: rotational speed (n) 2600 r / min, depth of cut (ap) 3 μm, feed rate (f) 0.0015 mm / r. The dimensional deviation of the conical surface of the special fixture is measured to be 0.8 μm using a microscope, and the surface roughness of the conical surface of the special fixture is measured to be Ra 17 nm using a white light interferometer, which meets the technical requirements of the special fixture.

[0048] c. Assemble the hemispherical mandrel ball onto the special fixture, and at the same time use a negative pressure pump to draw negative pressure to fix the hemispherical mandrel ball. The negative pressure value is 0.8 atm. Eliminate the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture, and eliminate external factors that affect the uniformity of the wall thickness of the hemispherical aluminum shell. Then fill the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture with 502 glue.

[0049] d. After the 502 glue has cured and formed a 502 glue layer, the negative pressure pump is removed, and the hemispherical mandrel ball is machined by ultra-precision turning to form the inner spherical surface of the hemispherical aluminum shell, thus obtaining the hemispherical aluminum shell to be processed. The machining parameters are: rotation speed (n) 2600 r / min, depth of cut (ap) 2.5 μm, and feed rate (f) 0.002 mm / r. The dimensional deviation of the inner spherical surface of the hemispherical aluminum shell is measured to be 0.2 μm using a microscope, and the surface roughness of the inner spherical surface of the hemispherical aluminum shell is measured to be Ra7 nm using a white light interferometer, which meets the technical requirements for the inner spherical surface of the hemispherical aluminum shell.

[0050] e. Remove the 502 adhesive layer between the hemispherical aluminum shell to be treated and the conical surface of the special fixture by soaking in acetone, clean the hemispherical aluminum shell to be treated, and dry it to obtain the desired hemispherical aluminum shell with a wall thickness uniformity of 0.8μm.

[0051] The special fixture includes a special fixture column, a special fixture cone surface, a negative pressure channel, and a negative pressure pump; the negative pressure pump is detachable.

[0052] The cone angle of the special fixture's conical surface is 80°; the cone height is 0.35 mm; and the diameter of the center hole is 0.35 mm.

[0053] One end of the negative pressure channel is connected to the negative pressure pump, and the other end is connected to the center hole of the conical surface of the special fixture.

[0054] Example 2

[0055] This embodiment is used to manufacture a material with a wall thickness of 0.07 mm and an inner diameter of [missing information]. A hemispherical aluminum shell with a crown height of 0.54 mm (greater than the shell radius of 0.45 mm) is used. The implementation method is basically the same as that of Example 1, with the main difference being the wall thickness and inner diameter of the manufactured hemispherical aluminum shell.

[0056] The manufacturing method of this embodiment includes the following steps:

[0057] a. Material preparation: Solid aluminum cylinders are machined into hemispherical mandrels using ultra-precision turning. The machining parameters are: rotation speed (n) 2500 r / min, depth of cut (ap) 0.5 μm, and feed rate (f) 0.001 mm / r. The dimensional deviation of the hemispherical mandrel is 0.4 μm as measured by a microscope, and the surface roughness of the hemispherical mandrel is Ra14 nm as measured by a white light interferometer, meeting the technical requirements for hemispherical mandrels.

[0058] b. The solid copper core shaft is machined into the required special fixture through precision turning, milling, and ultra-precision turning. The machining parameters for precision turning are: rotational speed (n) 1800 r / min, depth of cut (ap) 5.5 μm, feed rate (f) 0.0015 mm / r; the machining parameters for milling are: rotational speed (n) 8600 r / min, depth of cut (ap) 20 μm, feed rate (f) 300 mm / min; and the machining parameters for ultra-precision turning are: rotational speed (n) 2600 r / min, depth of cut (ap) 3 μm, feed rate (f) 0.0015 mm / r. The dimensional deviation of the conical surface of the special fixture is measured to be 0.7 μm using a microscope, and the surface roughness of the conical surface of the special fixture is measured to be Ra 16 nm using a white light interferometer, which meets the technical requirements of the special fixture.

[0059] c. Assemble the hemispherical mandrel ball onto the special fixture, and at the same time use a negative pressure pump to draw negative pressure to fix the hemispherical mandrel ball. The negative pressure value is 0.9 atm. This eliminates the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture, and eliminates external factors that affect the uniformity of the wall thickness of the hemispherical aluminum shell. Then fill the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture with 502 glue.

[0060] d. After the 502 glue has cured and formed a 502 glue layer, remove the negative pressure pump and machine the hemispherical mandrel ball using ultra-precision turning to form the inner spherical surface of the hemispherical aluminum shell, thus obtaining the hemispherical aluminum shell to be processed. The machining parameters are: rotation speed (n) 2500 r / min, depth of cut (ap) 0.5 μm, and feed rate (f) 0.001 mm / r. The dimensional deviation of the inner spherical surface of the hemispherical aluminum shell is measured to be 0.3 μm using a microscope, and the surface roughness of the inner spherical surface of the hemispherical aluminum shell is measured to be Ra7 nm using a white light interferometer, which meets the technical requirements for the inner spherical surface of the hemispherical aluminum shell.

[0061] e. Remove the 502 adhesive layer between the hemispherical aluminum shell to be treated and the conical surface of the special fixture by soaking in acetone, clean the hemispherical aluminum shell to be treated, and dry it to obtain the desired hemispherical aluminum shell with a wall thickness uniformity of 0.9μm.

[0062] The special fixture includes a special fixture column, a special fixture cone surface, a negative pressure channel, and a negative pressure pump; the negative pressure pump is detachable.

[0063] The cone angle of the special fixture's conical surface is 80°; the cone height is 0.45 mm; and the diameter of the center hole is 0.38 mm.

[0064] One end of the negative pressure channel is connected to the negative pressure pump, and the other end is connected to the center hole of the conical surface of the special fixture.

[0065] Example 3

[0066] This embodiment is used to manufacture a material with a wall thickness of 0.08 mm and an inner diameter of [missing information]. A hemispherical aluminum spherical shell with a crown height of 0.6 mm (greater than the shell radius of 0.5 mm).

[0067] The manufacturing method of this embodiment includes the following steps:

[0068] a. Material preparation: Solid aluminum cylinders are machined into hemispherical mandrels using ultra-precision turning. The machining parameters are: rotation speed (n) 3000 r / min, depth of cut (ap) 5 μm, and feed rate (f) 0.005 mm / r. The dimensional deviation of the hemispherical mandrel is 0.6 μm as measured by a microscope, and the surface roughness of the hemispherical mandrel is Ra17 nm as measured by a white light interferometer, meeting the technical requirements for hemispherical mandrels.

[0069] b. The solid copper core shaft is machined into the required special fixture through precision turning, milling, and ultra-precision turning. The machining parameters for precision turning are: rotational speed (n) 1800 r / min, depth of cut (ap) 5.5 μm, feed rate (f) 0.0015 mm / r; the machining parameters for milling are: rotational speed (n) 8600 r / min, depth of cut (ap) 20 μm, feed rate (f) 300 mm / min; and the machining parameters for ultra-precision turning are: rotational speed (n) 2600 r / min, depth of cut (ap) 3 μm, feed rate (f) 0.0015 mm / r. The dimensional deviation of the conical surface of the special fixture is measured to be 0.8 μm using a microscope, and the surface roughness of the conical surface of the special fixture is measured to be Ra 18 nm using a white light interferometer, which meets the technical requirements of the special fixture.

[0070] c. Assemble the hemispherical mandrel ball onto the special fixture, and at the same time use a negative pressure pump to draw negative pressure to fix the hemispherical mandrel ball. The negative pressure value is 0.8 atm. Eliminate the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture, and eliminate external factors that affect the uniformity of the wall thickness of the hemispherical aluminum shell. Then fill the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture with 502 glue.

[0071] d. After the 502 glue has cured and formed a 502 glue layer, remove the negative pressure pump and machine the hemispherical mandrel ball using ultra-precision turning to form the inner spherical surface of the hemispherical aluminum shell, thus obtaining the hemispherical aluminum shell to be processed. The machining parameters are: rotation speed (n) 3000 r / min, depth of cut (ap) 5 μm, and feed rate (f) 0.005 mm / r. The dimensional deviation of the inner spherical surface of the hemispherical aluminum shell is measured to be 0.3 μm using a microscope, and the surface roughness of the inner spherical surface of the hemispherical aluminum shell is measured to be Ra 8 nm using a white light interferometer, which meets the technical requirements for the inner spherical surface of the hemispherical aluminum shell.

[0072] e. Remove the 502 adhesive layer between the hemispherical aluminum shell to be treated and the conical surface of the special fixture by soaking in acetone, clean the hemispherical aluminum shell to be treated, and dry it to obtain the desired hemispherical aluminum shell with a wall thickness uniformity of 1.1μm.

[0073] The special fixture includes a special fixture column, a special fixture cone surface, a negative pressure channel, and a negative pressure pump; the negative pressure pump is detachable.

[0074] The cone angle of the special fixture's conical surface is 80°; the cone height is 0.5 mm; and the diameter of the center hole is 0.4 mm.

[0075] One end of the negative pressure channel is connected to the negative pressure pump, and the other end is connected to the center hole of the conical surface of the special fixture.

[0076] The yield rate of the hemispherical aluminum shells prepared using Examples 1-3 was 100%.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for manufacturing a hemispherical aluminum spherical shell, characterized in that, The manufacturing method includes the following steps: a. machining a solid aluminum column into a hemispherical mandrel ball using ultra-precision turning; b. machining a solid copper mandrel into a required special fixture using precision turning, milling, and ultra-precision turning; the special fixture includes a special fixture column, a special fixture conical surface, a negative pressure channel, and a negative pressure pump; the negative pressure pump is detachable; the cone angle of the special fixture conical surface is 80°; the cone height is 0.35mm to 0.5mm, and it is consistent with the radius of the hemispherical mandrel ball; the diameter of the center hole is 0. 35mm~0.4mm; c. Assemble the hemispherical mandrel ball on the special fixture, and at the same time use a negative pressure pump to draw negative pressure to fix the hemispherical mandrel ball, eliminating the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture, and then fill the gap at the tangent point between the hemispherical mandrel ball and the conical surface of the special fixture with 502 glue; d. After the 502 glue has cured to form a 502 glue layer, remove the negative pressure pump, and machine the hemispherical mandrel ball by ultra-precision turning to form the inner spherical surface of the hemispherical aluminum shell, thus obtaining the hemispherical aluminum shell to be processed; e. Remove the 502 adhesive layer between the hemispherical aluminum shell to be treated and the conical surface of the special fixture by soaking in acetone, clean the hemispherical aluminum shell to be treated, and dry it to obtain the desired hemispherical aluminum shell; the machining process parameters for the hemispherical mandrel ball in step d by ultra-precision turning are: rotation speed n is 2600 r / min, depth of cut ap is 2.5 μm, and feed rate f is 0.002 mm / r; the dimensions of the outer spherical surface of the hemispherical mandrel ball, the conical surface of the special fixture, the outer cylindrical surface of the special fixture column, and the inner spherical surface of the hemispherical aluminum shell obtained by turning in steps a, b, and d are respectively... The dimensional deviations are all less than 1.5μm, and the surface roughness is less than Ra20nm; one end of the negative pressure channel is connected to the negative pressure pump, and the other end is connected to the center hole of the conical surface of the special fixture; the wall thickness h of the hemispherical aluminum shell ranges from 0.06mm to 0.08mm; the inner diameter Øa of the hemispherical aluminum shell ranges from Ø0.7mm to Ø1.0mm; the crown height L of the hemispherical aluminum shell ranges from 0.43mm to 0.6mm; the turning process parameters in steps a, b, and d are as follows: the rotational speed n ranges from 1800r / min to 3000r / min, the depth of cut ap ranges from 0.5μm to 5.5μm, and the feed rate f ranges from 0.001mm / r to 0.005mm / r.

2. The application of the hemispherical aluminum spherical shell manufactured by the method for manufacturing a hemispherical aluminum spherical shell as described in claim 1, characterized in that, The application is that the hemispherical aluminum shell, after being processed with inner and outer stops and then assembled into a complete aluminum shell, can be used for loading gaseous, liquid, solid, foam or powder materials.

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