A machining method for improving the profile tolerance of a large integral frame part flange

Abstract

The present application relates to the field of machining, in particular to a machining method for improving the profile tolerance of a large integral frame part flange; the large area of the flange of the part is determined according to the measurement result of the machined part; the anti-deformation ability of the flange is increased by thickening the inner surface of the flange, and the amount of the flange deformation is reduced; the maximum allowable thickness T max and the minimum allowable thickness T min of the flange are set to determine the wall thickness fluctuation range of the flange of the part during the machining and manufacturing of the part, and the wall thickness tolerance band of the flange of the part is enlarged; the flange deformation generated after the finish machining and sufficient natural aging of the part is eliminated by supplementing the flange profile allowance of the part to be machined, and the profile tolerance of the flange of the integral frame part is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of machining, and specifically relates to a machining method for improving the profile of the flange of a large integral frame part. Background Technology

[0002] To simultaneously meet the requirements of high strength and low weight, large integral frame components for aircraft are typically designed with large-sized cavities and thin-walled, low-rigidity plateau structures. The forged blanks used for these large integral frame components have high residual stress. After the parts are machined to the required dimensions, the residual stress in the blank material rebalances, leading to machining deformation. The flanges of the components will exhibit tilting deformation under the combined influence of the specific flange structure strength and the residual stress distribution of the blank. This tilting deformation manifests as "outward tilting deformation" and "inward tilting deformation." Because the flange surfaces of large integral frame components are closely fitted to the aircraft's outer skin, the tolerance for measuring the outline is high. Due to the high residual stress in the forged blanks and the thin wall thickness of the flanges, traditional machining methods cannot meet the design specifications for the part's outline. Summary of the Invention

[0003] This invention addresses the problem that existing processing methods cannot meet the design specifications for the flange shape of parts when the residual stress of the forged blank used in machining is high and the flange is a thin-walled, weakly rigid structure. It proposes a machining method to improve the flange shape of large integral frame parts. The method involves determining the area of ​​large tilt deformation of the flange based on measurements of already machined parts; increasing the flange's deformation resistance and reducing the amount of tilt deformation by thickening the inner surface of the flange; and setting a maximum allowable thickness T for the flange. max Minimum allowable thickness T of the flange min The range of fluctuation in the wall thickness of the part flange during part processing and manufacturing is determined, and the tolerance zone of the part flange wall thickness is enlarged; by supplementing the part flange shape allowance in the area to be processed, the flange tilting deformation caused by the part finishing and sufficient natural aging is eliminated, and the overall frame part flange shape contour is effectively improved.

[0004] The specific implementation details of this invention are as follows:

[0005] A machining method for improving the profile of the flange of a large integral frame part involves the following operations on the machined part:

[0006] Operation 1: Thicken the inner surface of the flange of the part to increase the flange's resistance to deformation and reduce the amount of flange tilting deformation;

[0007] Operation 2: Set the maximum allowable thickness T of the flange. max Minimum allowable thickness T of the flange min Determine the fluctuation range of the flange wall thickness during part processing and manufacturing, and enlarge the flange wall thickness tolerance zone;

[0008] Operation 3: supplement the part rim profile margin of the region to be processed, and eliminate the rim tilt deformation generated after the part is finished and fully naturally aged;

[0009] Operation 4: set the part processing route, and set the part processing state margin according to the processing route.

[0010] In order to better realize the present application, further, the processing method comprises the following steps:

[0011] Step 1: according to the measurement result of the processed part, determine the part rim profile contour out-of-tolerance region, and take the part rim profile contour out-of-tolerance region as the rim profile region to be supplemented;

[0012] Step 2: thicken the part rim inner surface, set the maximum allowable thickness T max and the minimum allowable thickness T min of the rim, enlarge the part rim wall thickness tolerance band, and complete the structure setting of the rim profile region to be supplemented;

[0013] Step 3: set the part processing route, supplement the part rim profile margin of the region to be supplemented, and set the part processing state margin according to the part processing route, and complete the part rim processing.

[0014] In order to better realize the present application, further, the part processing route set in the step 3 is: rough machining of the part A surface and B surface → natural aging → semi-finishing of the part A surface and B surface → natural aging → finishing of the part A surface and B surface → supplementing the part rim profile margin of the region to be supplemented.

[0015] In order to better realize the present application, further, the part processing state margin set in the step 3 is: setting the Z-direction margin as Z1 and the side surface margin as S1 when rough machining the A surface and B surface, setting the Z-direction margin as Z2 and the side surface margin as S2 when semi-finishing the A surface and B surface, and setting the part rim profile margin of the region to be supplemented as β when finishing the A surface and B surface.

[0016] In order to better realize the present application, further, fully natural aging is performed before supplementing the part rim profile margin of the region to be processed, residual stress of the part material is fully released, and after deformation balance, the profile margin β is removed by cutting and milling according to the set theoretical strip-shaped surface under the same clamping state and processing origin, and the rim profile tilt deformation α is eliminated.

[0017] In order to better realize the present application, further, the thickness of the thickened part rim inner surface is greater than the maximum tilt deformation of the rim profile.

[0018] In order to better realize the present application, further, the minimum allowable bead thickness T min =T1+γ1, the maximum allowable bead thickness T max =T1+δ+γ2+α i ;

[0019] Wherein, T1 is the bead inner shape before thickening the theoretical thickness size of the front bead, δ is the thickening size of the bead inner shape surface, γ1 is the lower tolerance of the wall thickness tolerance band allowed by the manufacturing technology condition, γ2 is the upper tolerance of the wall thickness tolerance band allowed by the manufacturing technology condition, α i The maximum inner collection inclination deformation of the bead of the test piece in the early stage.

[0020] In order to better realize the present application, further, the Z direction allowance Z1 of the rough machining A surface and B surface is set to 6mm, the side surface allowance S1 is set to 4mm, the Z direction allowance Z2 of the semi-finishing machining A surface and B surface is set to 3mm, the side surface allowance S2 is set to 2mm, and the part bead shape allowance β of the A surface and B surface to be machined in the finishing machining is set to 1mm.

[0021] The present application has the following beneficial effects:

[0022] (1) The present application thickens the bead inner shape surface, realizes the redundant design of the part strength requirement, avoids the problem that the minimum measured wall thickness size after the part finishing machining cannot meet the design strength requirement; improves the bead rigidity, increases the bead anti-deformation capacity, and reduces the maximum inclination deformation of the bead; provides the possibility for process optimization and improvement of part machining and manufacturing method, and reduces the risk of elastic tooling when the part A surface and B surface finishing machining is completed, the bead inclination deformation is fully released, and the shape allowance β is removed by cutting and milling according to the theoretical bead shape surface.

[0023] (2) The present application enlarges the bead wall thickness tolerance band, meets the bead wall thickness fluctuation range during part machining and manufacturing, and ensures that the final bead thickness of the part meets the part design bead thickness tolerance requirement.

[0024] (3) The present application sets the machining route of the part manufacturing, and the bead shape surface of the part is finally sized by four times of machining. The part is machined several times, and the size is gradually machined to be in place. The semi-finishing machining can eliminate the bead inclination deformation generated after the part rough machining and natural aging, the finishing machining can eliminate the bead inclination deformation generated after the part semi-finishing machining and natural aging, and the supplementary machining shape allowance β can eliminate the bead inclination deformation generated after the part finishing machining and full natural aging, thereby avoiding the accumulation of machining deformation to the final part finished product state, and reducing the bead inclination deformation of the finished part.

[0025] (4) The present application sets the part machining state allowance according to the processing route, comprehensively analyzes the influencing factors of the part machining process stability and the full release of the blank residual stress, meets the full release of the blank residual stress in the part machining process, reduces the edge strip inclined deformation of the final product part, and meets the reasonable edge strip wall thickness during part machining and the stable machining process without vibration and the quality problem of the elastic knife.

[0026] (5) In the finish machining of the part A surface and B surface, only the edge strip contour degree measurement size area of the exposed edge strip of the early test part is reserved with a supplementary machining allowance β, and the size of the remaining part is machined in place, thereby effectively improving the overall frame part edge strip contour degree.

[0027] (6) The present application adopts the integrated collaborative improvement of part design and manufacturing to solve the technical problems in part machining and manufacturing. First, the machining result of the early test part exposes the design problem of the part, which makes up for the traditional part design method which only relies on the finite element simulation software to analyze the part strength and cannot truly simulate and analyze the influence of the blank residual stress on the part machining deformation. The part manufacturing end realizes the closed-loop feedback of the part manufacturing design requirements to the part design end. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The flowchart of the processing method of the embodiment of the present application is shown.

[0029] Figure 2 The schematic diagram of the machining allowance setting of the overall frame part of the embodiment of the present application is shown.

[0030] Figure 3 The specific flowchart of step S2 of the processing method of the embodiment of the present application is shown.

[0031] Figure 4 The specific flowchart of step S3 of the processing method of the embodiment of the present application is shown.

[0032] Figure 5 The supplementary machining area sectional view of the edge strip contour surface containing the process boss of the embodiment of the present application is shown.

[0033] Figure 6 The local sectional view of the supplementary machining area of the edge strip contour surface not containing the process boss of the embodiment of the present application is shown.

[0034] Figure 7 The schematic diagram of the edge strip outward tilt deformation is shown.

[0035] Figure 8 The schematic diagram of the edge strip inward tilt deformation is shown.

[0036] Figure 9 The schematic diagram of the structure before the edge strip thickening is shown.

[0037] Figure 10 The structure of the thickened rim strip.

[0038] Figure 11 The structure of the part after rough machining of the A and B surfaces and the allowance setting.

[0039] Figure 12 The structure of the part after semi-finishing machining of the A and B surfaces and the allowance setting.

[0040] Figure 13 The structure of the part after finishing machining of the A surface and the allowance setting.

[0041] Figure 14 The structure of the part after finishing machining of the B surface and the allowance setting.

[0042] Figure 15 The structure of the part after 7-day natural aging and the allowance setting after milling to remove the rim strip contour allowance.

[0043] Figure 16 The structure of the rim strip part in the embodiment of the application.

[0044] Figure 17 The actual wall thickness size of the C part of the rim strip contour before supplementary machining of the contour allowance β.

[0045] Figure 18 The actual wall thickness size of the C part of the rim strip contour after supplementary machining of the contour allowance β.

[0046] Figure 19 The actual wall thickness size of the D part of the rim strip contour before supplementary machining of the contour allowance β.

[0047] Figure 20 The actual wall thickness size of the D part of the rim strip contour after supplementary machining of the contour allowance β.

[0048] Figure 21 The actual wall thickness size of the E part of the rim strip contour before supplementary machining of the contour allowance β.

[0049] Figure 22 The actual wall thickness size of the E part of the rim strip contour after supplementary machining of the contour allowance β.

[0050] Wherein, 1, first supplementary machining rim strip contour area, 2, second supplementary machining rim strip contour area, 3, process boss, 4, part rim strip, 5, rim strip contour surface, 6, Z-direction allowance, 7, side surface allowance, 8, blank allowance, 9, final part, 10, outward tilting deformation rim strip, 11, theoretical rim strip, 12, web, 13, inward tilting deformation rim strip, 14, part rim strip contour allowance, 15, rim strip wall thickness deviation. DETAILED DESCRIPTION

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be understood that the described embodiments are only some of the embodiments of the present application, not all the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0052] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "set", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] Embodiment 1

[0054] The present embodiment proposes a processing method for improving the contour of the large overall frame part edge strip, and the following operations are performed on the processed part:

[0055] Operation 1: Thicken the inner surface of the part edge strip 4, increase the anti-deformation ability of the edge strip, and reduce the amount of edge strip tilt deformation;

[0056] Operation 2: Set the maximum allowable thickness T of the edge strip max and the minimum allowable thickness T of the edge strip min , determine the wall thickness fluctuation range of the part edge strip 4 during part processing and manufacturing, and enlarge the wall thickness tolerance band of the part edge strip 4;

[0057] Operation 3: Supplement the part edge strip contour allowance 14 of the region to be processed, and eliminate the tilt deformation of the edge strip generated after the part is finished and fully naturally aged;

[0058] Operation 4: Set the part processing route, and set the part processing state allowance according to the processing route.

[0059] Working principle: the embodiment thickens the inner profile surface of the part edge strip 4, realizes the redundant design of the part strength requirement, avoids the problem that the minimum measured wall thickness size of the finished part cannot meet the design strength requirement, improves the rigidity of the edge strip, increases the anti-deformation ability of the edge strip, and reduces the maximum inclination deformation amount of the edge strip; provides the possibility for process optimization and improvement of part machining and manufacturing method, reduces the risk of elastic cutter when the part edge strip is removed according to the theoretical edge strip 11 outer profile surface after the A surface and B surface of the finished part are finished and the inclination deformation of the edge strip is fully released; by setting the maximum allowable thickness T max and the minimum allowable thickness T min of the edge strip, the wall thickness fluctuation range of the part edge strip 4 during part machining and manufacturing is determined, the edge strip wall thickness tolerance band is enlarged, the theoretical edge strip shape of the part requires additional processing area edge strip is β, because the A surface and B surface of the finished part are finished and fully naturally aged, the edge strip will be "outwardly expanded" or "inwardly contracted" inclination deformation, the actual processing removal amount β i of the additional processing meets: β-α i <β+α o , wherein α i is the maximum inward inclination deformation amount of the edge strip, and α o is the maximum outward inclination deformation amount of the edge strip. Before the part edge strip shape allowance 14 is processed, the inclination deformation problem of the part edge strip increases the wall thickness size fluctuation range of the part edge strip after the part is additionally processed. Enlarging the edge strip wall thickness tolerance band can meet the edge strip wall thickness fluctuation range during part machining and manufacturing, and ensure that the final edge strip thickness of the part meets the edge strip thickness tolerance requirement of the part design.

[0060] Embodiment 2

[0061] Based on the above embodiment 1, as shown in Figure 1 , the processing method comprises the following steps:

[0062] Step 1: according to the measurement result of the processed part, the part edge strip shape contour exceeds the area, and the part edge strip shape contour exceeds the area is taken as the additional processing edge strip shape area;

[0063] Step 2: thicken the inner profile surface of the part edge strip 4, set the maximum allowable thickness T max and the minimum allowable thickness T min of the edge strip, enlarge the wall thickness tolerance band of the part edge strip 4, and complete the structure setting of the additional processing edge strip shape area;

[0064] Step 3: set the part processing route, supplement the part edge strip shape allowance 14 of the additional processing edge strip shape area, and set the part processing state allowance according to the part processing route, complete the processing of the part edge strip 4.

[0065] Working principle: This embodiment determines the large area of ​​inclined deformation of the flange strip based on the measurement results of the previously processed parts; optimizes the structural design of the flange strip in the area of ​​out-of-tolerance measurement of the part's outline: thickens the inner surface of the flange strip and enlarges the flange strip wall thickness tolerance zone; optimizes the part processing and manufacturing method: when finishing the A and B surfaces of the part, leaves a machining allowance on the outer surface of the flange strip in the area of ​​inclined deformation. After the part is finished, it is fully naturally aged to fully release the residual stress of the part material. After the machining deformation is balanced and stabilized, it is milled according to the theoretical flange strip 11 under the same clamping state and machining origin to remove the flange strip outline allowance 14, thereby eliminating the inclined deformation of the flange strip and effectively improving the overall frame part flange strip outline.

[0066] The other parts of this embodiment are the same as those in Embodiment 1 above, so they will not be described again.

[0067] Example 3:

[0068] This embodiment is based on any one of the above embodiments 1-2, such as Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, a detailed explanation is given using a large integral frame aircraft structural component with blank material model 7050-T7452 and blank type of die forging.

[0069] This invention employs an integrated approach to component design and manufacturing to address technical challenges in component processing and manufacturing. Firstly, the processing results of initial test parts reveal design flaws, overcoming the limitations of traditional component design methods that rely solely on finite element simulation software to analyze component strength. These methods fail to accurately simulate the impact of residual stress in the blank on component deformation during processing. This achieves a closed-loop feedback mechanism between the component manufacturing end and the component design end, providing feedback on component manufacturing design requirements.

[0070] Specifically, the following steps are included:

[0071] Step S1: Based on the measurement results of the previously processed parts, determine the outer area of ​​the part's edge with large tilt deformation, i.e., the area with out-of-tolerance profile.

[0072] The design parameters for the flange structure of the preliminary test piece are as follows: flange wall thickness T1 = 3; total flange height H = 170; single-sided flange H1 = 70; maximum allowable flange thickness T max＝ 3.1; Minimum allowable flange thickness T min= 2.8; the tolerance of the edge strip shape profile is ±0.3. The processing scheme of the early test piece is a traditional scheme, and the specific processing flow and allowance setting are as follows: rough machining of A surface and B surface, Z-direction allowance Z1 = 6mm, side surface allowance S1 = 6mm, natural aging, semi-finishing of A surface and B surface, Z-direction allowance Z2 = 3mm, side surface allowance S2 = 4mm, natural aging, finishing of A surface and B surface, and all sizes are machined in place. By analyzing the measurement results of the early test piece, the edge strip shape profile is measured by a three-coordinate measuring machine, and the edge strip thickness size is measured by a wall thickness micrometer, it is determined that the first supplementary machining edge strip shape area 1 and the second supplementary machining edge strip shape area 2 are the edge strip shape profile measurement out-of-tolerance areas of the test piece, and the edge strip shape profile measurement deviation range is: -0.5~+0.8mm, that is, the maximum inward tilting deformation amount a i of the edge strip is 0.5, and the maximum outward tilting deformation amount a o of the edge strip is 0.8mm. The actual measured wall thickness size T of the edge strip is: 2.7mm≤T≤3.2mm. The processing result of the early test piece proves that: due to the fact that the residual stress level of the die forging blank material cannot be improved, and the current part edge strip design structure parameters, the traditional part processing and manufacturing scheme cannot process qualified finished parts.

[0073] In order to meet the processing requirements of the edge strip shape profile of the large integral frame part ±0.3mm, ensure the effective assembly of the edge strip shape surface of the large integral frame part and the outer skin of the aircraft, and optimize and improve the edge strip structure design of the edge strip shape profile measurement out-of-tolerance area of the large integral frame part, the processing and manufacturing scheme of the large integral frame part is optimized and improved. The specific implementation technical scheme is as follows:

[0074] Step S2: optimizing the structure design of the edge strip of the part shape profile measurement out-of-tolerance area

[0075] Step S21: thickening the inner shape surface of the edge strip by δ, δ = 1mm, the theoretical thickness of the improved edge strip is increased from 3mm to 4mm, the strength of the edge strip is improved after the thickness of the edge strip is increased, the ability to resist the residual stress of the blank is improved, and the tilting deformation amount a i of the part edge strip size after machining in place will be reduced;

[0076] The beneficial harvest of thickening the inner shape surface of the edge strip δ is: the redundant design of the strength requirement of the part is realized, the problem that the minimum actual measured wall thickness size of the part after completing the machining cannot meet the design strength requirement is avoided; the rigidity of the edge strip is improved, the anti-deformation ability of the edge strip is increased, and the maximum tilting deformation amount of the edge strip is reduced; the possibility of optimizing and improving the part processing and manufacturing method is provided, and the risk of elastic tooling when the part A surface and B surface are finished, the edge strip tilting deformation is fully released, and the edge strip shape surface of the theoretical edge strip 11 is machined by cutting and milling to remove the part edge strip shape allowance 14.

[0077] Step S22: Enlarge the edge strip wall thickness tolerance band. The part manufacturing method of the supplementary processing part edge strip profile allowance 14 used in this embodiment can effectively improve the edge strip profile contour, ensuring that the edge strip profile surface of the large integral frame part effectively matches the assembly of the aircraft outer skin. Before supplementary processing the part edge strip profile allowance 14, the edge strip has already produced an inclined deformation amount a i which will make the fluctuation range of the actual measured edge strip thickness T after supplementary processing to remove the part edge strip profile allowance 14 be enlarged. Enlarging the edge strip wall thickness tolerance band can meet the edge strip wall thickness fluctuation range during part processing and manufacturing, ensuring that the wall thickness of the finished part edge strip 4 meets the design wall thickness tolerance requirement. After enlarging the edge strip wall thickness tolerance band, the minimum allowable edge strip thickness T min = T1+ γ1= 3+ (-0.2) = 2.8 mm; the maximum allowable edge strip thickness T max = T1+ δ+ γ2+ α i = 3+1+0.1+0.5=4.6 mm. Among them: T1=3 mm is the theoretical thickness of the edge strip before the edge strip is thickened, δ=1 mm is the thickening size of the edge strip profile, γ1=-0.2 mm is the lower tolerance of the wall thickness tolerance band allowed by the manufacturing technical conditions, γ2=0.1 mm is the upper tolerance of the wall thickness tolerance band allowed by the manufacturing technical conditions, α i =0.5 mm is the maximum inward inclined deformation amount of the edge strip of the previous test part. The minimum allowable edge strip thickness T min ensures the minimum design wall thickness required by the structure strength of the large integral frame part of this embodiment, and the maximum allowable edge strip thickness T max ensures that the actual measured edge strip thickness of the large integral frame part of this embodiment meets the design wall thickness tolerance requirement.

[0078] The beneficial harvest of enlarging the edge strip wall thickness tolerance band is that the part requires supplementary processing of the edge strip profile theoretical allowance β. After the part completes the A surface and B surface finishing and fully naturally ages, the edge strip will produce "expansion" or "retraction" inclined deformation. The actual processing removal amount βi of supplementary processing satisfies: β-αi<β+αo, where αi is the maximum edge strip inward inclined deformation amount, and αo is the maximum edge strip outward inclined deformation amount. Before supplementary processing the part edge strip profile allowance 14, the inclined deformation problem of the part edge strip increases the edge strip wall thickness size fluctuation range after the part is supplementary processed. Enlarging the edge strip wall thickness tolerance band can meet the edge strip wall thickness fluctuation range during part processing and manufacturing, ensuring that the final edge strip thickness of the part meets the part design edge strip thickness tolerance requirement.

[0079] Step S3: Optimize the part processing and manufacturing method:

[0080] Step S31: the part processing route is: rough machining A surface, B surface → natural aging → semi-finishing A surface, B surface → natural aging → finishing A surface, B surface → sufficient natural aging → supplementary machining part edge shape allowance 14; the edge shape surface of the part of the embodiment of the application is finally sized in place through 4 times of machining. The beneficial harvest of multiple turning and machining of the part to gradually size in place is that semi-finishing can eliminate the edge tilt deformation of the part after rough machining and natural aging, finishing can eliminate the edge tilt deformation of the part after semi-finishing and natural aging, and the part edge shape allowance 14 can eliminate the edge tilt deformation of the part after finishing and sufficient natural aging, thereby avoiding the accumulation of machining deformation to the final part finished product state and reducing the edge tilt deformation of the finished part.

[0081] Step S32: part each machining state allowance setting: rough machining: Z-direction allowance Z1=6mm, side surface allowance S1=4mm; semi-finishing: Z-direction allowance Z2=3mm, side surface allowance S2=2mm; finishing: except that the edge shape allowance β=1mm is left in the region needing supplementary machining, the rest is all machined in place; the machining allowance setting of the part of the embodiment of the application comprehensively analyzes two influencing factors of part machining process stability and sufficient release of blank residual stress, which not only satisfies sufficient release of blank residual stress in the part machining process and reduces the edge tilt deformation of the final finished part, but also satisfies reasonable edge thickness of the part during machining, stable machining process, and no vibration of the quality of the spring tool.

[0082] Step S33: the part edge shape allowance 14 of the part needs to be fully naturally aged before 1mm, the part material residual stress is fully released, the machining deformation is balanced and stable, and then the part edge shape allowance 14 is removed by cutting and milling according to the theoretical edge shape 11 in the same clamping state and machining origin, which eliminates the edge shape tilt deformation α and effectively improves the overall frame part edge shape profile.

[0083] Reasonable Z-direction allowance Z i Can be used for process scheme to control the overall warping deformation of the part, and the application does not expand the discussion on technical details. The part side surface allowance S i The larger the part side surface allowance S iThe smaller the actual wall thickness of the edge strip is, the closer to the final processing state of the part, and the smaller the edge strip side machining allowance can release the blank residual stress more fully, release the edge strip tilt deformation in advance, and reduce the edge strip tilt deformation after the part edge strip appearance allowance 14 is machined. The preferred machining allowance setting of the application comprehensively analyzes the influencing factors of the part processing stability and the full release of the blank residual stress, which not only meets the full release of the blank residual stress in the part processing, reduces the edge strip tilt deformation of the final product part, but also meets the reasonable edge strip wall thickness during part processing and the stable processing without vibration.

[0084] In the part finishing of the part A surface and the part B surface of the embodiment of the application, only the edge strip appearance surface of the edge strip profile measurement size area of the part exposed in the early test is reserved with a supplementary machining allowance β=1, and the rest of the size is machined in place. After the part is finished, the part is extremely close to the final product part state, the blank residual stress is at the lowest after the part is naturally aged, and the part geometry profile and the residual stress reach a balanced stable state after the processing deformation is fully released. At this time, the edge strip appearance surface size of the whole frame part theoretical edge strip 11 is finished again to eliminate the edge strip tilt deformation generated by the finishing of the A surface and the B surface. When the last numerical control machining process supplements the part edge strip appearance allowance 14, the residual stress of the part has been reduced to a lower level after the residual stress is released in the early stage, and the ratio of the material removal amount to the final wall thickness size T of the edge strip when the part edge strip appearance allowance 14 is supplemented is small, β / T=1 / 4. The newly generated edge strip tilt deformation of the part edge strip appearance allowance 14 is also greatly reduced, and the edge strip appearance profile of the whole frame part is effectively improved.

[0085] Summary: By implementing the part design and machining method for improving the edge strip appearance profile of the large whole frame part, the edge strip appearance profile of the embodiment of the large whole frame part is greatly improved, and meets the technical requirement of the edge strip appearance profile measurement tolerance of ±0.3mm. The edge strip wall thickness of the part product also meets the wall thickness tolerance requirement of 2.8mm-4.7mm.

[0086] The other parts of the embodiment are the same as any one of the above embodiments 1-2, and will not be described again.

[0087] The above is only the preferred embodiment of the application, and does not limit the application in any form. Any simple modification and equivalent change made according to the technical essence of the application to the above embodiment also falls within the protection scope of the application.

Claims

1. A method of improving the profile of a large monolithic frame part bead, comprising: The following operations are performed on the machined part: First, according to the measurement results of the machined part, the part edge strip contour out-of-tolerance area is determined, and the part edge strip contour out-of-tolerance area is taken as the part edge strip contour area to be supplemented; Operation 1: Thicken the inner surface of the part edge strip (4), increase the anti-deformation amount of the part edge strip (4), and reduce the inclined deformation amount of the part edge strip (4); Operation 2: Set the maximum allowable thickness T of the rim strip max And the minimum allowable thickness T of the rim strip min Determine the wall thickness fluctuation range of the rim strip (4) of the part during machining manufacturing, increase the wall thickness tolerance band of the rim strip (4) of the part, and complete the structure setting of the contour area of the rim strip to be supplemented machining; Operation 3: Set the part processing route, supplement the part edge strip contour allowance (14) of the part edge strip contour out-of-tolerance area, and set the part processing state allowance according to the part processing route. Milling and cutting processing removes the part edge strip contour allowance (14), eliminates the inclined deformation amount of the part edge strip caused by part finishing and sufficient natural aging.

2. A method of improving the profile of a large monolithic frame part bead as claimed in claim 1, wherein, The part processing route set in operation 3 is: rough machining of part A surface and B surface → natural aging → semi-finishing of part A surface and B surface → natural aging → finishing of part A surface and B surface → supplementing the part edge strip contour allowance (14) of the part edge strip contour area to be supplemented.

3. A method of improving the profile of a large monolithic frame part bead as claimed in claim 2, wherein, Before supplementing the part edge strip contour allowance (14) of the part edge strip contour area, sufficient natural aging is performed to fully release the residual stress of the part material, and after the deformation balance, the part edge strip contour allowance (14) is removed by cutting and milling according to the set theoretical strip surface in the same clamping state and processing origin, eliminating the inclined deformation amount of the part edge strip contour.

4. A method of improving the profile of a large monolithic frame part bead as claimed in any one of claims 1 to 3, wherein, The thickness of the thickened inner surface of the part edge strip (4) is greater than the maximum inclined deformation amount of the edge contour.

5. A method of improving the profile of a large monolithic frame part bead as claimed in any one of claims 1 to 3, wherein, Minimum allowed thickness T of the set bead min Maximum allowed thickness T of the bead max =T1+δ+γ2+α i ; Wherein, T1 is the theoretical thickness size of the front edge strip of the inner profile of the edge strip, δ is the thickening size of the inner profile surface, γ1 is the lower tolerance of the wall thickness tolerance band allowed by the manufacturing technical conditions, γ2 is the upper tolerance of the wall thickness tolerance band allowed by the manufacturing technical conditions, α i is the maximum inward tilting deformation of the edge strip of the pre-test piece.

6. The method of claim 2 wherein the method further comprises the step of: The Z-direction allowance Z1 during rough machining of A surface and B surface is set to 6mm, and the side surface allowance S1 is set to 4mm. The Z-direction allowance Z2 during semi-finishing of A surface and B surface is set to 3mm, and the side surface allowance S2 is set to 2mm. The part edge strip contour allowance (14) of the to-be-processed area during finishing of A surface and B surface is set to 1mm.

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