A method for manufacturing an aircraft skin stereoscopic inspection device

Abstract

This invention belongs to the field of aircraft skin structure, specifically a method for manufacturing a three-dimensional inspection device for aircraft skin. Using 3D software based on a digital model of the part, a digital model of the three-dimensional inspection device containing positioning process holes is designed. A blank of the three-dimensional inspection device is formed using an aircraft skin forming fixture, and the outer contour of the three-dimensional inspection device is machined using a CNC machine tool with flexible adsorption clamps. Compared with existing skin inspection devices, the advantages of this invention are: shortened mold usage time, reduced skin inspection time, and reduced floor space required for the production of the skin inspection fixture.

Description

Technical Field

[0001] This invention belongs to the field of aircraft skin structure, specifically a method for manufacturing a three-dimensional inspection device for aircraft skin. Background Technology

[0002] Aircraft fuselage skin components are crucial structural parts of aircraft and play a vital role in their aerodynamic shape. The accuracy of the fuselage skin's shape significantly impacts the aircraft's performance. Fuselage skin components exhibit the following characteristics: 1. Complex shape. 2. High shape accuracy requirements. 3. Large structural dimensions, relatively small thickness, and poor rigidity. 4. Large forming fixtures, resulting in long production preparation time. 5. Long production cycle. Currently, the shape contour is primarily inspected using the outline lines on forming fixtures or specialized inspection jigs with clamps. However, the large size of fuselage skin components and the substantial volume and weight of forming fixtures or inspection jigs can lead to slow production turnover and low inspection efficiency. Therefore, a three-dimensional inspection device for aircraft skin components is needed to inspect their shape and curvature. This device should be simple in structure, easy to manufacture, and convenient to use and store. Summary of the Invention

[0003] Purpose of the invention

[0004] This invention overcomes the shortcomings of the prior art and provides a method for manufacturing a three-dimensional inspection device for aircraft skin.

[0005] Technical solution

[0006] A method for manufacturing a three-dimensional inspection device for aircraft skin involves using 3D software to design a digital model of the inspection device containing positioning process holes based on a digital model of the part. A blank of the three-dimensional inspection device is then formed using an aircraft skin forming fixture. Finally, the outer contour of the three-dimensional inspection device is machined using a CNC machine tool equipped with a flexible adsorption fixture. The method includes the following steps:

[0007] Step 1: Use 3D software to extract the inner surface of the part.

[0008] Step 2: Based on the inner surface extracted in Step 1, use the surface thickening function of 3D software to create a 3D inspection device digital model.

[0009] Step 3: Based on the inspection device model created in Step 2, design two process lugs in both the length and direction of the model, and design positioning holes on the process lugs.

[0010] Step 4: Stretch and shape the blank according to the molding mold to form a three-dimensional inspection device.

[0011] Step 5: Based on the drill template on the forming mold, make auxiliary positioning holes in the length direction on the blank of the three-dimensional inspection device.

[0012] Step 6: Using a CNC machine tool, auxiliary positioning holes are drilled on the machine tool positioning block according to the process model of the three-dimensional inspection device.

[0013] Step 7: Align the auxiliary positioning holes drilled on the machine tool positioning block made in Step 6 with the auxiliary positioning holes drilled on the blank of the three-dimensional inspection device made in Step 5, and use the flexible fixture of the CNC machine tool to position the main positioning holes drilled in the width direction on the blank of the three-dimensional inspection device.

[0014] Step 8: Remove the blank of the three-dimensional inspection device with the main positioning hole drilled in Step 7 from the CNC machine tool, and use the CNC machine tool to drill the main positioning hole on the machine tool positioning block according to the process model of the three-dimensional inspection device.

[0015] Furthermore, it also includes step nine: drilling the main positioning hole of the machine tool positioning block made in step eight and aligning it with the main positioning hole on the blank of the three-dimensional inspection device made in step seven, and then using a CNC machine tool to process the three-dimensional inspection device according to the process model of the three-dimensional inspection device to obtain the shape of the three-dimensional inspection device.

[0016] Furthermore, in step two, the 3D software is CAT IA software.

[0017] Furthermore, in step two, the thickness of the thickened curved surface is 1.5 mm.

[0018] Furthermore, in step three, the process lugs and holes in the length direction are auxiliary positioning holes, while the process lugs and holes in the width direction are main positioning holes.

[0019] Furthermore, in step three, the inspection device digital model and the process lugs together form a three-dimensional inspection device process digital model.

[0020] Furthermore, in step three, the lug dimensions are 40mm × 20mm, and the positioning hole diameter is φ5.2mm.

[0021] Furthermore, the method is used to fabricate a three-dimensional inspection device for complex-shaped skins of aerospace fuselages.

[0022] The beneficial effects of this application are as follows:

[0023] Compared with existing skin inspection devices, the advantages of this invention are: shortening the usage time of the molding mold, reducing skin inspection time, and reducing the floor space occupied by the skin inspection tooling in the production site.

[0024] The usage time of the molding mold has been reduced from 5 days to 2 hours. The skin inspection time has been reduced from 4 hours to 1 hour. Based on a 2m×6m skin, the production site area for inspection tooling has been reduced from 12㎡ to 1.2㎡. Attached Figure Description

[0025] Figure 1This is a typical drawing of a skinned part.

[0026] Figure 2 This is a schematic diagram of a typical skinned part and a three-dimensional inspection device.

[0027] Figure 3 This is a schematic diagram of the process digital model of a three-dimensional inspection device.

[0028] Figure 4 This is a schematic diagram of the rough shape of the skin mold and the three-dimensional inspection device.

[0029] Figure 5 This is a schematic diagram of the machine tool positioning block and auxiliary positioning holes.

[0030] Figure 6 This is a schematic diagram of the machining of the main positioning hole of the blank for a three-dimensional inspection device.

[0031] Figure 7 This is a schematic diagram of the machine tool positioning block and the main positioning hole.

[0032] Figure 8 This is a schematic diagram of the external outline of the three-dimensional inspection device.

[0033] Figure 9 This is a flowchart of the steps of the present invention.

[0034] The symbols in the attached diagram are explained as follows: 1 is a typical skinned part, 2 is the inner surface model of the skinned part, 3 is the digital model of the 3D inspection device, 4 is the process lug in the length direction of the process digital model, 5 is the auxiliary positioning hole of the process digital model, 6 is the process lug in the width direction of the process digital model, 7 is the main positioning hole of the process digital model, 8 is the process digital model of the 3D inspection device, 9 is the forming mold of the skinned part, 10 is the blank of the 3D inspection device, 11 is the drill template on the forming mold, 12 is the auxiliary positioning hole in the length direction on the blank of the 3D inspection device, 13 is the positioning block of the CNC machine tool, 14 is the auxiliary positioning hole on the positioning block of the machine tool, 15 is the main positioning hole in the width direction of the blank of the 3D inspection device, 16 is the main positioning hole on the positioning block of the machine tool, and 17 is the outer shape of the 3D inspection device. Detailed Implementation

[0035] The present invention will be further described below with reference to embodiments. The following description represents only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] The method for precise machining of complex-shaped flat plate chemical milling parts according to the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0037] The processing method of the present invention is as follows:

[0038] Figure 1 This is a typical part drawing.

[0039] Step 1: Extract the inner surface 2 of part 1 using 3D software. The 3D software is CAT IA software.

[0040] Step 2: Based on the inner surface 2 extracted in Step 1, use the surface thickening function of 3D software to create a 3D inspection device model 3. In the aerospace manufacturing industry, the surface thickening thickness is 1.5mm.

[0041] Step 3: Based on the inspection device model 3 created in Step 2, design two process lugs in both the length and width directions of the model. Design positioning holes on the process lugs. The process lugs are 4 in the length direction and have auxiliary positioning holes 5; the process lugs are 6 in the width direction and have main positioning holes 7. The inspection device model and the process lugs together form a three-dimensional inspection device process model 8. The process lug dimensions in the aerospace manufacturing industry are 40mm × 20mm, and the positioning hole diameter is φ5.2mm.

[0042] Step 4: Based on part 1, stretch and form part 9 into the three-dimensional inspection device blank 10. In the aerospace manufacturing industry, the blank material for the three-dimensional inspection device is 2A12 aluminum plate with a thickness of 1.5mm. The outer boundary of the inspection device blank is more than 100mm larger than the outer boundary of the part.

[0043] Step 5: Based on the drill template 11 on the forming mold 9, make auxiliary positioning holes 12 in the length direction on the blank 10 of the three-dimensional inspection device. Because the blank of the three-dimensional inspection device adopts the forming curvature of the part mold, there is a material thickness difference between the curvature of the process model of the three-dimensional inspection device and the curvature of the part model. In order to eliminate the influence of the material thickness, the auxiliary positioning holes usually need to be made into oblong holes with a diameter of φ5.2mm.

[0044] Step Six: Using a CNC machine tool, auxiliary positioning holes 14 are drilled on the machine tool positioning block 13 according to the process model 8 of the three-dimensional inspection device. The CNC machine tool is an M2411 five-axis flexible skin contour milling machine.

[0045] Step 7: Drill auxiliary positioning holes 14 on the machine tool positioning block 13 prepared in Step 6 and align them with the auxiliary positioning holes 12 on the three-dimensional inspection device blank 10 prepared in Step 5. Use the flexible fixture of the CNC machine tool to position the three-dimensional inspection device blank 10 and drill the main positioning holes 15 in the width direction. By CNC machining the main positioning holes, the influence of the material thickness difference between the process model curvature of the three-dimensional inspection device and the part model curvature is finally eliminated.

[0046] Step 8: Remove the blank 10 of the three-dimensional inspection device with the main positioning hole 15 drilled in step 7 from the CNC machine tool, and use the CNC machine tool to drill the main positioning hole 16 on the machine tool positioning block 13 according to the process model 8 of the three-dimensional inspection device.

[0047] Step 9: Drill the main positioning hole 16 of the machine tool positioning block 13 made in Step 8 and align it with the main positioning hole 15 on the blank 10 of the three-dimensional inspection device made in Step 7. Then, process the three-dimensional inspection device outline 17 using a CNC machine tool according to the process model 8 of the three-dimensional inspection device.

[0048] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a three-dimensional inspection device for aircraft skin, characterized in that, Using three-dimensional software based on the part product model, the three-dimensional inspection device model containing the positioning process hole is designed, the three-dimensional inspection device blank is formed by the aircraft skin forming tooling, and the three-dimensional inspection device contour is processed by the numerical control machine tool with flexible suction clamp; including the following steps: Step one: using three-dimensional software to extract the inner surface of the part; Step two: according to the inner surface extracted in step one, using three-dimensional software to create a three-dimensional inspection device model by thickening the curved surface function; Step three: according to the inspection device model created in step two, two process lugs are designed on the length and direction of the model, and positioning holes are designed on the process lugs; Step four: according to the forming mold tire stretching forming three-dimensional inspection device blank; Step five: according to the drill template on the forming mold tire, the length direction auxiliary positioning hole is made on the three-dimensional inspection device blank; Step six: using numerical control machine tool to drill auxiliary positioning hole on machine positioning block according to three-dimensional inspection device process model; Step seven: the auxiliary positioning hole drilled in step six is coincided with the auxiliary positioning hole on the three-dimensional inspection device blank in step five, and the flexible clamp of numerical control machine tool is used to position the three-dimensional inspection device blank to drill the width direction main positioning hole; Step eight: the three-dimensional inspection device blank with main positioning hole drilled in step seven is removed from the numerical control machine tool, and the main positioning hole is drilled on the machine positioning block according to the three-dimensional inspection device process model.

2. The method of claim 1, wherein, Step nine: the main positioning hole drilled in step eight is coincided with the main positioning hole on the three-dimensional inspection device blank in step seven, and the numerical control machine tool is used to process the three-dimensional inspection device contour according to the three-dimensional inspection device process model.

3. The method of claim 1, wherein, In step two, the three-dimensional software is CATIA software.

4. The method of claim 1, wherein, In step two, the thickness of the thickened curved surface is 1.5mm.

5. The method of claim 1, wherein, In step three, the length direction process lug and hole are auxiliary positioning holes, and the width direction process lug and hole are main positioning holes.

6. The method of claim 1, wherein, In step three, the inspection device model and process lug composition are three-dimensional inspection device process model.

7. The method of claim 1, wherein, In step three, the lug size is 40mm x 20mm, and the positioning hole diameter is φ5.2mm.

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