A method for precisely machining the shape of complex flat-plate chemical milling parts

Abstract

The present invention belongs to the field of chemical milling of flat-plates for aviation aircraft, and relates to a method for precise machining of the shape of complex-shaped flat-plate chemical milling parts. The present invention utilizes three-dimensional design software to design a process digital model containing positioning process holes based on the part product digital model, and uses a CNC machine tool to perform precise machining of the part shape and inner hole. Compared with the existing marking milling and punching technologies, the beneficial effects of the present invention are: improving the accuracy of the part shape and inner hole, and reducing the number of punching tooling. The accuracy of the part shape and inner hole is reduced from 1mm to 0.1mm. The number of punching tooling is reduced to 0 sets; the present invention can also be used for precise machining of the shape of complex-shaped flat-plate chemical milling parts in aerospace.

Description

Technical Field

[0001] The invention belongs to the field of chemical milling of aircraft flat plates and relates to a method for accurately processing the shape of a complex-shaped flat plate chemical milling part. Background Art

[0002] Aircraft flat-plate chemical milling parts are flat-plate parts consisting of a chemical milling area and an inner shape. Aircraft aluminum alloy flat-plate chemical milling parts are typical and common structural parts in aircraft. The design of the chemical milling area can effectively improve the structural strength of the parts, and at the same time, it can effectively reduce the weight of the structure. In order to ensure the assembly accuracy of the aircraft structure, there are high requirements for the accuracy of the shape and inner hole of aircraft aluminum alloy flat-plate chemical milling parts. At present, the marking milling and punching methods are used to process the shape and inner hole of the parts after chemical milling. The parts processing technology is complicated, and a large number of special tooling needs to be manufactured. Ultimately, it is not possible to guarantee the accuracy of the relative position of the part shape and the inner hole and the shape of the chemical milling area, which easily leads to component assembly deviation. For this reason, it is necessary to study a method for accurately processing the shape of flat-plate chemical milling parts, reduce the complexity of the parts processing technology and the manufacturing cost, and at the same time ensure the accuracy of the part shape and inner hole processing. Summary of the Invention

[0003] The present invention overcomes the shortcomings of the prior art and provides a method for precisely machining the shape of complex flat-plate chemically milled parts. To address the aforementioned technical issues, the present invention utilizes 3D design software to design a digital model of the part, containing positioning holes, based on the part's product model. This method then uses a CNC machine tool to precisely machine the part's shape and internal holes.

[0004] Technical Solution

[0005] A method for accurately machining the shape of a complex-shaped flat-plate chemical milling part comprises the following steps:

[0006] Step 1: Use 3D design software to measure the part's outer dimensions 2 and 3.

[0007] Step 2: Based on the dimensions 2 and 3 measured in step 1, determine the number and direction of holes used for milling positioning and CNC.

[0008] If dimension 2 > dimension 3, the process holes are designed on both sides of dimension 2;

[0009] If dimension 2 is less than dimension 3, the process holes are designed on both sides of the direction of dimension 3;

[0010] Step 3: Design the process digital model according to the hole placement direction and quantity determined in Step 2. The process digital model consists of the part's outer contour, inner shape, chemical milling area, chemical milling area boundary, process hole lugs, and process holes.

[0011] Step 4: Create a chemical template based on the chemical milling area, chemical milling area boundary, part outer contour, process hole lug, and process hole shape in the process digital model. The chemical template consists of the chemical milling boundary, outer contour, process hole lug, and process hole.

[0012] Step 5: Make the rough part according to the chemical template. Drill the process holes of the rough part according to the chemical template.

[0013] Step 6: Protect the rough part with protective material according to the chemical milling process requirements. Place the chemical template over the rough part, align the process holes, and remove the protective material within the chemical milling boundary of the rough part. Protect the process holes according to the chemical milling process requirements, then chemically mill to the required depth of the part. Clean and dry the rough part after chemical milling, and remove the protective material from the non-chemically milled areas.

[0014] Step 7: Use a CNC machine tool to create a CNC line based on the digital model of the process model and then process. Before processing, place auxiliary padding on the machine platform. According to the process model, the external contour, internal shape, process hole lugs, and process holes are machined onto the auxiliary padding.

[0015] Step 8: Install the part blank processed in step 6 on the CNC machine. Align the process holes on the part blank with the process holes processed by CNC on the auxiliary pad in step 7 and fix the part blank.

[0016] Step 9: The part blank fixed in step 8 is processed again according to the CNC program of the process model in step 7 to finally obtain the precise outer contour and inner shape of the part.

[0017] Furthermore, the three-dimensional design software is CATIA.

[0018] Furthermore, if dimension 2 > dimension 3, the number of holes on each side of dimension 2 is 500 mm / hole, rounded to the nearest integer;

[0019] Furthermore, if dimension 2 is less than dimension 3, the number of holes per booklet on the length of dimension 3 is equal to dimension 3 / 500, rounding the integer.

[0020] Furthermore, the chemical sample is made of A3 steel or 2A12 aluminum plate, with a thickness of 2 mm.

[0021] Furthermore, the raw material of the part shall have a margin of no less than 40 mm around the size of the milling template.

[0022] Furthermore, the protective material in step 6 is specifically AC850 protective glue.

[0023] Furthermore, the auxiliary padding placed on the machine tool platform is made of wooden boards, aluminum boards or plastic boards.

[0024] Furthermore, the diameter of the process hole is φ5.2, and the size of the process hole lug 4 is 40 mm×20 mm.

[0025] Technical Effects

[0026] Compared with the existing marking and milling and punching technologies, the beneficial effects of the present invention are: improving the accuracy of the part shape and inner hole, and reducing the number of punching tools.

[0027] The precision of the part's shape and inner hole is reduced from 1mm to 0.1mm, and the number of punching tools is reduced to 0. The invention can also be used for precise shape processing of complex-shaped flat-plate chemical milling parts in aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a typical parts drawing.

[0029] Figure 2 This is a schematic diagram of the typical parts dimensions.

[0030] Figure 3 It is a schematic diagram of the process digital model.

[0031] Figure 4 It is a schematic diagram of a chemical sample.

[0032] Figure 5 It is a schematic diagram of the raw material of the part.

[0033] Figure 6 Flow chart of the steps of the present invention.

[0034] The codes in the accompanying drawings are explained as follows: 1 is the measured part, 2 is the part's outer dimensions, 3 is the part's outer dimensions, 4 is the process hole lug on the digital model, 5 is the process digital model, 6 is the digital model process hole, 7 is the part's outer contour, 8 is the part's inner shape, 9 is the part's chemical milling area, 10 is the part's chemical milling area boundary, 11 is the chemical milling template, 12 is the outer contour of the chemical milling template, 13 is the chemical milling engraving boundary of the chemical milling template, and 14 is the part's rough material. DETAILED DESCRIPTION

[0035] Example 1

[0036] The method for accurately processing the shape of a complex flat plate chemical milling part includes the following steps:

[0037] Step 1: Use 3D design software to measure the part's outer dimensions 2 and 3.

[0038] Step 2: Based on the dimensions 2 and 3 measured in step 1, determine the number and direction of holes used for milling positioning and CNC.

[0039] If dimension 2 > dimension 3, the process holes are designed on both sides of dimension 2;

[0040] If dimension 2 is less than dimension 3, the process holes are designed on both sides of the direction of dimension 3;

[0041] Step 3: Design the process digital model according to the hole placement direction and quantity determined in Step 2. The process digital model consists of the part's outer contour, inner shape, chemical milling area, chemical milling area boundary, process hole lugs, and process holes.

[0042] Step 4: Create a chemical template based on the chemical milling area, chemical milling area boundary, part outer contour, process hole lug, and process hole shape in the process digital model. The chemical template consists of the chemical milling boundary, outer contour, process hole lug, and process hole.

[0043] Step 5: Make the rough part according to the chemical template. Drill the process holes of the rough part according to the chemical template.

[0044] Step 6: Protect the rough part with protective material according to the chemical milling process requirements. Place the chemical template over the rough part, align the process holes, and remove the protective material within the chemical milling boundary of the rough part. Protect the process holes according to the chemical milling process requirements, then chemically mill to the required depth of the part. Clean and dry the rough part after chemical milling, and remove the protective material from the non-chemically milled areas.

[0045] Step 7: Use a CNC machine tool to create a CNC line based on the digital model of the process model and then process. Before processing, place auxiliary padding on the machine platform. According to the process model, the external contour, internal shape, process hole lugs, and process holes are machined onto the auxiliary padding.

[0046] Step 8: Install the part blank processed in step 6 on the CNC machine. Align the process holes on the part blank with the process holes processed by CNC on the auxiliary pad in step 7 and fix the part blank.

[0047] Step 9: The part blank fixed in step 8 is processed again according to the CNC program of the process model in step 7 to finally obtain the precise outer contour and inner shape of the part.

[0048] Furthermore, the three-dimensional design software is CATIA.

[0049] Furthermore, if dimension 2 > dimension 3, the number of holes on each side of dimension 2 is 500 mm / hole, rounded to the nearest integer;

[0050] Furthermore, if dimension 2 is less than dimension 3, the number of holes per booklet on the length of dimension 3 is equal to dimension 3 / 500, rounding the integer.

[0051] Furthermore, the chemical sample is made of A3 steel or 2A12 aluminum plate, and the thickness is generally 2 mm.

[0052] Furthermore, the raw material of the part shall have a margin of no less than 40 mm around the size of the milling template.

[0053] Furthermore, the protective material in step 6 is specifically AC850 protective glue.

[0054] Furthermore, the auxiliary pads placed on the machine tool platform can be made of materials with good surface quality such as wood boards, aluminum boards or plastic boards.

[0055] Furthermore, the diameter of the process hole is φ5.2, and the size of the process hole lug 4 is 40 mm×20 mm.

[0056] Example 2

[0057] The following is a further detailed description of the method for accurately processing the shape of a complex-shaped flat plate chemical milling part of the present invention in conjunction with the accompanying drawings and specific embodiments:

[0058] The processing method of the present invention is as follows:

[0059] Figure 1 This is a typical parts drawing.

[0060] Step 1: If Figure 2 As shown, the outer dimension 2 and outer dimension 3 of part 1 are measured using 3D design software (such as CATIA).

[0061] Part 1 shown in the figure measures dimension 2 = 1250 mm and dimension 3 = 510 mm.

[0062] Step 2: Based on the dimensions 2 and 3 measured in step 1, determine the number and direction of holes used for milling positioning and CNC.

[0063] If dimension 2 > dimension 3, the process holes are designed on both sides of dimension 2, and the number of holes on each side = dimension 2 / 500, rounded to the nearest integer;

[0064] If dimension 2 is less than dimension 3, the process holes are designed on both sides of the direction of dimension 3. The number of holes in each volume = dimension 3 / 500, rounded to the nearest integer.

[0065] As shown in the figure, part 1, because dimension 2 is greater than dimension 3, the process holes are designed on both sides of dimension 2, and the number of holes on each side = 1250 / 500 = 2. Figure 3 shown.

[0066] Step 3: If Figure 3As shown, according to the hole placement direction and number determined in step 2, the process digital model 5 is designed and completed. The process digital model 5 consists of the part outer contour 7, inner shape 8, chemical milling area 9, chemical milling area boundary 10, process hole lug 4 and process hole 6. Figure 3 The part shown has four process holes. The diameter of the process holes in the aviation manufacturing industry is φ5.2. The typical process hole lug size is 40mm x 20mm.

[0067] Step 4: If Figure 4 As shown, a milling template 11 is manufactured based on the milling area 9, milling boundary 10, outer contour 7, process hole lug 4, and process hole 6 of the part in the process digital model 5. The milling template 11 consists of a milling boundary 13, outer contour 12, process hole lug, and process hole. The milling template is made of A3 steel or 2A12 aluminum sheet. The material thickness is generally 2 mm.

[0068] Step 5: If Figure 5 As shown, a part blank 14 is made according to the chemical milling template 11. The part blank 14 is drilled with part process holes according to the chemical milling template 11. The outer dimensions of the part blank 14 are based on the characteristics of the chemical milling process, and usually a margin of not less than 40 mm is left around the size of the chemical milling template 11.

[0069] Step six: The part rough material 14 is protected with protective materials according to the chemical milling process requirements. Place the chemical milling template 11 on top of the part rough material 14, align and position it according to the process hole, and remove the protective material within the chemical milling engraving boundary 12 on the part rough material 14. After protecting the process holes according to the chemical milling process requirements, the part rough material 14 is chemically milled to the required depth of the part. Clean and dry the part rough material 14 after chemical milling and remove the protective material in the non-chemically milled area. In the aviation manufacturing industry, AC850 protective glue is usually used as the protective material for chemical milling, and a surgical blade is used to engrave when removing the protective material.

[0070] Step 7: Use a CNC machine tool (such as a Quino flatbed CNC milling machine) to create a CNC line based on the digital model of Process Module 5. Before processing, place auxiliary padding on the machine platform. According to Process Module 5, the outer contour, inner shape, process hole lugs, and process holes are machined onto the auxiliary padding. The auxiliary padding can be made of high-quality materials such as wood, aluminum, or plastic sheeting.

[0071] Step 8: Install the part blank 14 processed in step 6 on the CNC machine tool. Align the process holes on the part blank 14 with the process holes processed by CNC on the auxiliary pad in step 7 and fix the part blank 14.

[0072] Step 9: The part blank 14 fixed in step 8 is subjected to secondary processing according to the numerical control program of the process model 5 in step 7 to finally obtain the precise outer contour 7 and inner shape 8 of the part.

Claims

1. A method for accurately processing the shape of a complex flat plate chemical milling part, characterized in that: The steps include: Step 1: Use 3D design software to measure the part's dimensions 2 and 3; Step 2: Based on the dimensions 2 and 3 measured in step 1, determine the number and direction of holes used for milling positioning and CNC; If dimension 2 > dimension 3, the process holes are designed on both sides of dimension 2; If dimension 2 is less than dimension 3, the process holes are designed on both sides of the direction of dimension 3; Step 3: Design and complete the process digital model according to the hole placement direction and number determined in step 2; the process digital model consists of the part's outer contour, inner shape, chemical milling area, chemical milling area boundary, process hole lugs, and process holes; Step 4: Manufacturing a chemical sample based on the chemical milling area, chemical milling area boundary, part outer contour, process hole lug, and process hole shape in the process digital model; The chemical template consists of chemical milling edge, outer contour, process hole lug and process hole; Step 5: Make part rough material according to the chemical template; drill part process holes in the part rough material according to the chemical template; Step 6: The rough material of the parts is protected with protective materials according to the requirements of the chemical milling process; Place the chemical template on the part blank, align the process holes, and remove the protective material within the chemical milling boundary of the part blank; protect the process holes according to the chemical milling process requirements and then chemically mill the part blank to the required depth of the part; clean and dry the chemically milled part blank and remove the protective material in the non-chemically milled area; Step 7: Use a CNC machine tool to compile a CNC line according to the digital model of the process digital model for processing; before processing, place an auxiliary pad on the machine tool platform; according to the process digital model, process the outer contour, inner shape, process hole lug and process hole of the process digital model are processed on the auxiliary pad; Step 8: Install the rough part processed in step 6 on the CNC machine tool; Align the process holes on the part blank with the process holes processed by CNC on the auxiliary pad in step 7 and fix the part blank; Step 9: The part blank fixed in step 8 is processed again according to the CNC program of the process model in step 7 to finally obtain the precise outer contour and inner shape of the part.

2. The method for precisely machining the shape of a complex flat plate chemically milled part according to claim 1, characterized in that: The three-dimensional design software is CATIA.

3. The method for accurately processing the shape of a complex-shaped flat-plate chemical milling part according to claim 1 is characterized in that: If size 2 > size 3, the number of holes on each side of size 2 is 500mm / hole, rounded to the nearest integer.

4. The method for precisely machining the shape of a complex-shaped flat plate chemically milled part according to claim 1, characterized in that: If size 2 is less than size 3, the number of holes per booklet on the length of size 3 is equal to size 3 / 500, rounded to the nearest integer.

5. The method for precisely machining the shape of a complex-shaped flat plate chemically milled part according to claim 1, characterized in that: The chemical sample is made of A3 steel or 2A12 aluminum plate; the material thickness is 2mm.

6. The method for precisely machining the shape of a complex-shaped flat plate chemically milled part according to claim 1, characterized in that: The raw material of the parts should have a margin of no less than 40mm around the size of the milling template.

7. The method for precisely machining the shape of a complex-shaped flat plate chemically milled part according to claim 1, characterized in that: The protective material in step 6 is specifically AC850 protective glue.

8. The method for precisely machining the shape of a complex-shaped flat-plate chemically milled part according to claim 1, characterized in that: Auxiliary padding materials placed on the machine tool platform are made of wood, aluminum or plastic sheets.

9. The method for precisely machining the shape of a complex flat-plate chemically milled part according to claim 1, characterized in that: The diameter of the process hole is φ5.2, and the size of the process hole lug 4 is 40mm×20mm.

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