A method for processing hyperbolic milling skin

Abstract

The present invention belongs to the field of tooling manufacturing, and specifically relates to a method for processing a hyperbolic chemical milling skin; the method first designs a chemical milling process digital model and a mold process digital model based on the digital model design process information of the hyperbolic skin part product; manufactures a drawing chemical milling mold according to the chemical milling process digital model; manufactures a chemical milling template blank by the drawing chemical milling mold, and manufactures a chemical milling template from the chemical milling template blank according to the chemical milling process digital model; uses the mold process digital model to perform secondary processing on the drawing chemical milling mold to obtain a drawing skin mold; manufactures a hyperbolic skin blank based on the drawing chemical milling mold; uses the chemical milling template to perform chemical milling marking on the hyperbolic skin blank, and completes the hyperbolic skin chemical milling; uses the drawing skin mold to correct the hyperbolic skin deformed by chemical milling; and performs heat treatment on the hyperbolic skin to obtain a qualified part. The present invention can effectively speed up the production cycle, greatly reduce the deformation of parts caused by processing defects, and reduce processing costs.

Description

Technical Field

[0001] The invention belongs to the technical field of tooling manufacturing and relates to a method for processing a hyperbolic milled skin. Background Art

[0002] Skin parts not only ensure the aerodynamic shape of the aircraft, but are also important stress-bearing parts of the aircraft. Skin parts are generally large in size, complex in shape, thin and have poor rigidity. Aircraft skins have single curvature, but most are double curvature. In order to reduce weight, local thickness thinning is performed at locations where the skin parts are less stressed. Skin parts are usually made of 2A12 (usually about 2 to 4 mm). In actual processing, milling, chemical milling and other processing methods are usually used to form the groove structure.

[0003] The problems with the conventional processing currently used are: the milling processing method has a long processing time and low efficiency, and it is difficult to ensure the accuracy of the openings and assembly holes on the skin. Chemical milling is usually widely used in single-curved skins, but for hyperbolic skin parts with large areas and large curvature changes, they must be processed in steps, which is inefficient; it increases the complexity of the process; and the shape needs to be repeatedly calibrated, which seriously affects the processing progress of hyperbolic skin chemical milling parts. In summary, a new processing method is needed to process hyperbolic chemical milled skins. The processing process needs to ensure the processing accuracy of the parts, improve efficiency, and shorten the processing cycle. Summary of the invention

[0004] Purpose of the present invention: In order to solve the above existing problems, the present invention provides a method for processing hyperbolic milled skin. Under the premise of maintaining the advantages of the original processing method, the hyperbolic skin parts are processed by milling to solve the problems of hyperbolic deformation and low efficiency.

[0005] Technical solution:

[0006] A method for processing a hyperbolic milled skin, characterized in that the processing method comprises the following steps:

[0007] Step S1, based on the digital model design process information of the hyperbolic skin part product, respectively design the chemical milling process digital model and the mold and tire process digital model;

[0008] Step S2, manufacturing a drawing milling mold according to the milling process digital model;

[0009] Step S3, manufacturing a chemical milling template blank from a drawn chemical milling mold, and manufacturing a chemical milling template from the chemical milling template blank according to a chemical milling process digital model;

[0010] Step S4, using a mold process digital mold to perform secondary processing on the drawing milling mold to obtain a drawing skin mold;

[0011] Step S5, manufacturing a double-curved skin blank based on the drawing milling die;

[0012] Step S6, using a chemical milling template to perform chemical milling marking on the hyperbolic skin blank, and completing the chemical milling of the hyperbolic skin;

[0013] Step S7, using a tensile skin mold to correct the hyperbolic skin deformed by milling;

[0014] Step S8, performing heat treatment on the hyperbolic skin.

[0015] Further, step S1 is to design the pin holes, chemical milling positioning holes, assembly positioning holes, and chemical milling allowance line process information based on the digital model of the hyperbolic skin part product to obtain chemical milling process digital models and mold tire process digital models, specifically including:

[0016] Based on the digital model of the hyperbolic skin part product, the mold base plane is obtained by offsetting the part thickness from the theoretical skin shape surface, so as to design the skin shape line, and the process information of the milling positioning holes, assembly positioning holes and pin holes is added to the mold base plane to obtain the digital model of the mold process;

[0017] The chemical milling reference plane is obtained by offsetting the mold base reference plane, and the process information of chemical milling positioning holes, assembly positioning holes and pin holes in the mold process digital model is projected onto the chemical milling reference plane. Then the chemical milling allowance line and the chemical milling area viewport are designed to obtain the chemical milling process digital model.

[0018] Further, step S2 manufactures a drawing milling mold according to the milling process digital model, and the specific steps are:

[0019] Design the drawing and milling digital model according to the chemical milling process digital model;

[0020] According to the drawing and milling digital model, the drawing and milling mold tire is manufactured by CNC machining with CNC machine tools;

[0021] Laser scanning technology is used to check the mold process information to ensure that the mold meets the design requirements.

[0022] Further, step S3 specifically includes the following steps:

[0023] When the milling template blank is manufactured by the drawing milling die, the milling template blank is fitted with the drawing milling die. If the milling template blank and the drawing milling die do not fit, they are repaired until they fit.

[0024] The CNC machine tool is used to mill the shape, milling area viewport and milling allowance line on the milling sample blank, and the milling is completed in one time without leaving any artificial filing allowance;

[0025] Insert diamond sleeves into the pin holes, milling positioning holes, and assembly positioning holes on the milling template;

[0026] Spray paint and mark the milling template blank to form the final milling template.

[0027] Further, step S4 uses the mold process digital model to perform secondary processing on the drawing milling mold to obtain the drawing skin mold, and the specific steps are:

[0028] Design the digital model of the stretched skin according to the digital model of the mold process;

[0029] According to the digital model of the stretched skin, secondary CNC machining is performed on the stretched milling mold to manufacture the stretched skin mold;

[0030] Laser scanning technology is used to check the process information of the stretched skin mold to ensure that the stretched skin mold meets the design requirements.

[0031] Further, step S6 uses the chemical milling template to perform chemical milling marking on the skin blank and completes the hyperbolic skin chemical milling. The specific steps are:

[0032] The skin blank is first CNC milled to shape;

[0033] The milling positioning holes, assembly positioning holes and pin holes on the chemical skin blank are manufactured according to the chemical milling template, and the positions of the pin holes, chemical milling positioning holes and assembly positioning holes on the chemical milling template correspond one by one;

[0034] Fix the skin blank and the milling template together with a movable pin, and carve the milling allowance line on the skin blank according to the milling template;

[0035] Chemical raw materials are applied to the milling allowance line area of ​​the skin blank, and multiple milling is performed according to different milling depth requirements.

[0036] Further, in step S8, subsequent heat treatment includes artificial aging, penetration, oxidation, painting, and stress relief treatment.

[0037] Furthermore, the chemical milling reference surface is obtained by offsetting the die process digital model reference surface by the sum of the thickness of the chemical milling template and the thickness of the chemical milling glue layer.

[0038] Furthermore, the milling allowance line is obtained by paralleling the milling line on the milling reference plane with a certain width, and the parallel width is the milling depth multiplied by the corrosion coefficient; the milling area viewport is selected at the position of the non-linear part of the milling allowance line.

[0039] Furthermore, the material of the chemical milling template is 2A12-T4, and the thickness δ of the chemical milling template is 2.0 mm; the surface layer of the drawing chemical milling mold and the drawing skin mold is epoxy resin.

[0040] Beneficial effects:

[0041] The present invention provides a method for processing hyperbolic milled skin. It can effectively reduce the deformation of hyperbolic skin parts caused by milling, hot surfacing and other processing processes, and ensure processing accuracy; at the same time, it solves the complex process of milling processing methods for hyperbolic skin parts; it can effectively improve production efficiency, reduce tooling costs, and shorten the manufacturing cycle of hyperbolic skin parts; BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the hyperbolic milling skin;

[0043] Figure 2 It is a schematic diagram of the mold base surface and the milling base surface;

[0044] Figure 3 It is a chemical milling sample and chemical milling mold. DETAILED DESCRIPTION

[0045] The following is a further detailed description of the specific implementation of the present invention, such as the shape, structure, mutual position and connection relationship between the various components involved, the function and working principle of each part, the manufacturing process and the operation method, etc., through the description of the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention:

[0046] like Figure 1 As shown, a method for processing a hyperbolic chemical milling skin is provided. The processing method comprises the following steps: Step S1, based on the digital model design process information of the hyperbolic skin part product, respectively designing a chemical milling process digital model and a mold and tire process digital model;

[0047] Specifically, the step S1 includes:

[0048] Step S11: Based on the digital model of the hyperbolic skin part product, the thickness of the part is offset from the theoretical skin shape surface to obtain the mold base surface, so as to design the skin shape line, and add the process information of the chemical milling positioning holes, assembly positioning holes and pin holes to the mold base surface to obtain the digital model of the mold process; the chemical milling reference surface is obtained by offsetting the thickness of the chemical milling sample and the thickness of the chemical milling glue layer from the mold base process digital model reference surface, such as Figure 2 shown.

[0049] Step S12: The chemical milling reference plane is obtained by offsetting the mold base plane, and the process information of the chemical milling positioning holes, assembly positioning holes and pin holes in the mold process digital model is projected onto the chemical milling reference plane, and then the chemical milling allowance line and the chemical milling area viewport are designed to add the chemical milling allowance line, and the chemical milling process digital model is designed. It should be noted that the chemical milling allowance line is obtained by paralleling the chemical milling line on the chemical milling reference plane with a certain width, and the parallel width is the chemical milling depth multiplied by the corrosion coefficient. There is no need to calculate the chemical milling allowance line in sequence for multiple chemical milling, so as to avoid duplication of work. It should be noted that the chemical milling area viewport is selected at the position of the non-straight part of the chemical milling allowance line, so as to visually detect whether the chemical milling is qualified.

[0050] Step S2, manufacturing a drawing milling mold according to the milling process digital model;

[0051] Specifically, step S2 includes:

[0052] Step S21: designing a drawing milling digital model according to the milling process digital model;

[0053] Step S22: According to the drawing milling digital model, CNC machining is performed by a CNC machine tool to manufacture a drawing milling mold;

[0054] Step S23: using laser scanning technology to check the mold process information so that the mold meets the design requirements.

[0055] Step S3, manufacturing a chemical milling template blank from a drawn chemical milling mold, and manufacturing a chemical milling template from the chemical milling template blank according to a chemical milling process digital model;

[0056] Specifically, step S3 includes:

[0057] Step S31: when manufacturing a milling template blank from a drawing milling mold, the milling template blank is fitted to the drawing milling mold. If the milling template blank and the drawing milling mold do not fit together, they are repaired until they fit together.

[0058] Step S32: Milling the outer shape, milling area viewport and milling allowance line on the milling sample blank by a CNC machine tool, and milling in place at one time without leaving any manual filing allowance;

[0059] Step S33: inserting diamond sleeves into the pin holes, the milling positioning holes, and the assembly positioning holes on the milling template;

[0060] Step S34: spray paint and mark the milling template blank to form the final milling template.

[0061] It should be noted that when milling the outer shape, milling area viewport and engraving the milling allowance line, milling is done in one go without leaving any allowance for manual filing, which can improve processing accuracy and reduce processing time.

[0062] It should be noted that the material of the milling sample is 2A12-T4, and the thickness of the milling sample is 2.0 mm. It can bend well with the curvature and ensure good rigidity.

[0063] Step S4, using a mold process digital mold to perform secondary processing on the drawing milling mold to obtain a drawing skin mold;

[0064] Specifically, step S4 includes:

[0065] Step S41: designing a tensile skin digital model according to the mold process digital model;

[0066] Step S42: performing secondary CNC machining on the tensile milling mold according to the tensile skin digital model to manufacture the tensile skin mold;

[0067] Step S43: using laser scanning technology to check the process information of the stretched skin mold, so that the stretched skin mold meets the design requirements.

[0068] It should be noted that the surface of the drawing milling mold and the drawing skin mold in steps S2 and S4 has epoxy resin, which has good chemical resistance, strong paint film adhesion, good heat resistance and electrical insulation, good paint film color retention, and is easy to shape and engrave.

[0069] Step S5, manufacturing a double-curved skin blank based on the drawing milling die;

[0070] Step S6, using a chemical milling template to perform chemical milling marking on the hyperbolic skin blank, and completing the chemical milling of the hyperbolic skin;

[0071] Specifically, step S6 includes:

[0072] Step S61: The skin blank is first subjected to CNC milling to cut the shape;

[0073] Step S62: milling positioning holes, assembly positioning holes, and pin holes on the chemical skin blank are manufactured according to the chemical milling template, and the positions of the pin holes, chemical milling positioning holes, and assembly positioning holes on the chemical milling template correspond one to one;

[0074] Step S63: fixing the skin blank and the chemical milling template together with a movable latch, and carving a chemical milling allowance line on the skin blank according to the chemical milling template;

[0075] Step S64: Apply chemical raw materials in the area of ​​the milling allowance line of the skin blank, and perform milling multiple times according to different milling depth requirements.

[0076] Step S7, using a tensile skin mold to correct the hyperbolic skin deformed by milling;

[0077] Step S8, performing heat treatment on the hyperbolic skin.

[0078] It should be noted that in step S8, the subsequent heat treatment includes artificial aging, penetration, oxidation, and painting, which can eliminate various defects caused by the processing technology, eliminate segregation, reduce and eliminate internal stress, and extend the service life of parts.

[0079] In summary, the present invention belongs to the field of tooling manufacturing, and specifically relates to a method for processing hyperbolic chemical milling skin. The method first adds process information such as pin holes, chemical milling positioning holes, assembly positioning holes, and chemical milling allowance lines to the product digital model to obtain chemical milling process digital models and mold tire process digital models respectively; based on the chemical milling process digital model, a drawing chemical milling mold tire is manufactured; a chemical milling template blank is manufactured from the drawing chemical milling mold tire, and the chemical milling template is accurately processed using numerical control means according to the chemical milling process digital model; the drawing chemical milling mold tire is subjected to secondary processing according to the mold tire process digital model to obtain a drawing skin mold tire, and a hyperbolic skin blank is obtained from the drawing chemical milling mold tire; the hyperbolic skin is chemically milled according to the chemical milling template, and the hyperbolic skin is chemically milled; the chemical milling deformation of the parts is trimmed according to the drawing skin mold tire; and subsequent heat treatments such as infiltration, oxidation, and painting are performed to obtain qualified parts. The present invention can effectively speed up the production cycle, greatly reduce the deformation of parts caused by milling, hot surfacing and other processing processes of hyperbolic skin parts, and ensure processing accuracy; at the same time, it solves the complex process of milling processing methods for hyperbolic skin parts; it can effectively improve production efficiency, reduce tooling costs, and shorten the manufacturing cycle of hyperbolic skin parts.

[0080] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for processing a hyperbolic milled skin, characterized in that: The processing method comprises the following steps: Step S1, based on the digital model design process information of the hyperbolic skin part product, respectively design the chemical milling process digital model and the mold and tire process digital model; Step S1 is to design the pin holes, chemical milling positioning holes, assembly positioning holes, and chemical milling allowance line process information based on the digital model of the hyperbolic skin part product to obtain chemical milling process digital models and mold tire process digital models, specifically including: Based on the digital model of the hyperbolic skin part product, the mold base plane is obtained by offsetting the part thickness from the theoretical skin shape surface, so as to design the skin shape line, and the process information of the milling positioning holes, assembly positioning holes and pin holes is added to the mold base plane to obtain the digital model of the mold process; The chemical milling reference plane is obtained by offsetting the mold base plane, and the process information of the chemical milling positioning holes, assembly positioning holes and pin holes in the mold base process digital model is projected onto the chemical milling reference plane, and then the chemical milling allowance line and the chemical milling area viewport are added to design and obtain the chemical milling process digital model; Step S2, manufacturing a drawing milling mold according to the milling process digital model; Step S3, manufacturing a chemical milling template blank from a drawn chemical milling mold, and manufacturing a chemical milling template from the chemical milling template blank according to a chemical milling process digital model; Step S4, using a mold process digital mold to perform secondary processing on the drawing milling mold to obtain a drawing skin mold; Step S5, manufacturing a hyperbolic skin blank based on the pull-shaped skin mold; Step S6, using a chemical milling template to perform chemical milling marking on the hyperbolic skin blank, and completing the chemical milling of the hyperbolic skin; Step S7, using a tensile skin mold to correct the hyperbolic skin deformed by milling; Step S8, performing heat treatment on the hyperbolic skin.

2. The method for processing a hyperbolic milled skin according to claim 1, characterized in that: Step S2 manufactures a drawing milling mold according to the milling process digital model, and the specific steps are as follows: Design the drawing and milling digital model according to the chemical milling process digital model; According to the drawing and milling digital model, the drawing and milling mold tire is manufactured by CNC machining with CNC machine tools; Laser scanning technology is used to check the mold process information to ensure that the mold meets the design requirements.

3. The method for processing a hyperbolic milled skin according to claim 1, characterized in that: The specific steps of step S3 are: When the milling template blank is manufactured by the drawing milling die, the milling template blank is fitted with the drawing milling die. If the milling template blank and the drawing milling die do not fit, they are repaired until they fit. The CNC machine tool is used to mill the shape, milling area viewport and milling allowance line on the milling sample blank, and the milling is completed in one time without leaving any artificial filing allowance; Insert diamond sleeves into the pin holes, milling positioning holes, and assembly positioning holes on the milling template; Spray paint and mark the milling template blank to form the final milling template.

4. The method for processing a hyperbolic milled skin according to claim 1, characterized in that: Step S4 uses the mold process digital model to perform secondary processing on the drawing milling mold to obtain a drawing skin mold. The specific steps are: Design the digital model of the stretched skin according to the digital model of the mold process; According to the digital model of the stretched skin, secondary CNC machining is performed on the stretched milling mold to manufacture the stretched skin mold; Laser scanning technology is used to check the process information of the stretched skin mold to ensure that the stretched skin mold meets the design requirements.

5. The method for processing a hyperbolic milled skin according to claim 1, characterized in that: Step S6 uses the chemical milling template to perform chemical milling marking on the skin blank and complete the hyperbolic skin chemical milling. The specific steps are: The skin blank is first CNC milled to shape; The chemical milling positioning holes, assembly positioning holes and pin holes on the skin blank are manufactured according to the chemical milling template, and the positions of the chemical milling positioning holes, assembly positioning holes and pin holes on the chemical milling template correspond one to one; Fix the skin blank and the milling template together with a movable pin, and carve the milling allowance line on the skin blank according to the milling template; Chemical raw materials are applied to the milling allowance line area of ​​the skin blank, and multiple milling is performed according to different milling depth requirements.

6. The method for processing a hyperbolic milled skin according to claim 1, characterized in that: In step S8, subsequent heat treatment includes artificial aging, penetration, oxidation, painting, and stress relief treatment.

7. The method for processing a hyperbolic milled skin according to claim 2, characterized in that: The chemical milling reference surface is obtained by offsetting the mold process digital model reference surface by the sum of the thickness of the chemical milling template and the thickness of the chemical milling glue layer.

8. The method for processing a hyperbolic milled skin according to claim 2, characterized in that: The chemical milling allowance line is obtained by paralleling the chemical milling line on the chemical milling reference plane with a certain width, and the parallel width is the chemical milling depth multiplied by the corrosion coefficient; the chemical milling area viewport is selected at the position of the non-straight part of the chemical milling allowance line.

9. The method for processing a hyperbolic milled skin according to claim 1, characterized in that: The material of the chemical milling sample is 2A12-T4, and the thickness of the chemical milling sample is δ2.0mm; the surface layer of the drawing chemical milling mold and the drawing skin mold is epoxy resin.

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