A processing method of a weak-rigid thin-wall single-mounting-edge exhaust support

Abstract

The present application relates to the technical field of aircraft engine exhaust support, and relates to a processing method of weak-rigidity thin-wall single-mounting-edge exhaust support, and specifically comprises the following steps: S1: cavity filling: filling with potting material at the cavity of the workpiece to increase the overall processing rigidity of the workpiece; S2: rough processing and semi-finish processing: taking the single mounting edge of the outer casing as a processing reference, and under the condition that a margin is reserved at the reference, removing the material of the dimension irrelevant to the reference; S3: finish processing: grinding the single mounting edge of the outer casing to make the design reference ground out; S4: super-finish processing: reversely clamping the workpiece by using a tool, so that the supporting surface is located at the upper end surface and the pressing surface is located at the lower end surface, and taking the design reference as the processing reference to process the remaining dimension. The present application can realize the non-overturning processing of the mounting edge, and ensure the perpendicularity and flatness of the mounting edge to be qualified; meanwhile, the processing reference and the design reference coincide, and the precision of the dimension related to the design reference is ensured to meet the design requirement.

Description

Technical Field

[0001] This invention relates to the field of aero-engine exhaust support technology, and more specifically, to a method for processing a weakly rigid, thin-walled, single-mounting-side exhaust support. Background Technology

[0002] The exhaust bearing of an aero-engine is a critical component connecting the engine's hot-end components to the aircraft's rear fuselage. Its functions include load-bearing, force transmission, rotor alignment, airflow organization and loss reduction, smoothly guiding high-temperature exhaust gases out of the engine, and minimizing total pressure loss to improve propulsion efficiency. To achieve complex functions in extreme environments, the exhaust bearing structure is characterized by a ring frame consisting of an "outer casing," an "inner casing," and a load-bearing hollow support plate connecting them. The core challenge in its design lies in minimizing weight while ensuring structural and functional integrity. Therefore, low rigidity and thin walls are its most prominent features, posing significant manufacturing difficulties. Its machining accuracy directly impacts the engine's reliability, safety, and maintainability. Currently, when machining the cantilever mounting edge and the holes on the mounting edge connected to the outer casing of the exhaust bearing, axial forces can cause the mounting edge to "tilt." Furthermore, due to multiple mounting seats and a large flare on the outer casing sidewall, and the design datum being on the upper end face of the mounting edge, conventional process routes and support / clamping methods cannot guarantee datum coincidence. This inconsistency between the machining datum and the design datum results in significant positional dimensional deviations. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing exhaust support manufacturing processes, such as the tendency to tip over and the large positional dimensional deviations caused by inconsistencies between the manufacturing datum and the design datum. This invention provides a manufacturing method for a weakly rigid, thin-walled exhaust support with a single mounting edge, which enables the mounting edge to be manufactured without tipping over, ensuring that the verticality and flatness of the mounting edge are up to standard. At the same time, the manufacturing datum coincides with the design datum, ensuring that the accuracy of the dimensions related to the design datum meets the design requirements.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for manufacturing a weakly rigid, thin-walled, single-mounting-edge venting support is provided, specifically including the following steps: S1: Cavity filling: Filling the cavities of the workpiece with potting material to increase the overall machining rigidity of the workpiece; S2: Rough machining and semi-finishing: Using the single mounting edge of the outer casing as the machining datum, and with the datum having a allowance, material is removed from dimensions unrelated to the datum. S3: Finishing: Grinding the single mounting edge of the outer casing to bring out the design reference; S4: Ultra-precision machining: The workpiece is clamped in reverse using a tooling, so that the supporting surface is on the upper end face and the pressing surface is on the lower end face. The remaining dimensions are machined using the design datum as the machining datum.

[0005] Since the design datum of the exhaust support is on the upper end face of the mounting edge, conventional forward clamping and pressing cannot guarantee datum alignment. This invention increases the rigidity of the workpiece and reduces the chance of tipping over by filling the cavity with potting material. Then, using a special tooling, the entire exhaust support is clamped in reverse, thereby increasing support for the exhaust support and ensuring that the mounting edge does not tip over. Simultaneously, with the design datum and support both located on the upper end face of the mounting edge, the inverted installation ensures that the design datum and machining datum coincide. Not all machining dimensions of the entire exhaust support are related to the datum. During machining, dimensions unrelated to the datum are machined first, then the design datum is ground out, and finally, dimensions related to the design datum are machined, thus improving machining accuracy.

[0006] Preferably, step S2 is as follows: S21: Rough turning datum: The axial and radial datum of the workpiece are converted to the single mounting edge of the outer casing. Rough machining is performed with the datum having a reserved allowance, and the inner casing is cut with a predetermined allowance. S22: CNC vertical machining: The workpiece angle is converted to the reference point and the mounting edge of the outer casing is transferred, and the mounting base on the side wall of the outer casing is machined to the design dimensions.

[0007] Preferably, in the rough machining step S21, the allowance reserved for the reference is 0.06mm~0.1mm.

[0008] Preferably, the finishing process in step S3 involves grinding the single mounting edge of the outer casing to the design reference using an external cylindrical grinding method.

[0009] Preferably, step S4 is as follows: S41: CNC vertical machining: The machining datum is set at the design datum, and the precision dimensions of the outer casing, inner casing, hollow support plate and the datum are machined. S42: Internal grinding: Grinding the precision dimensions of the inner casing based on the design angular datum, surface datum, and radial datum.

[0010] Preferably, the precision dimensions related to the reference in step S41 include the flatness, perpendicularity, and roundness of the single mounting edge, as well as the position of the holes on the single mounting edge and the inner casing end face.

[0011] Preferably, the precision dimensions of the inner casing in step S42 include the coaxiality of the inner casing and the outer casing, the flatness of the end face of the inner casing, and the inner bore diameter of the inner casing.

[0012] Preferably, step S1 is as follows: filling the hollow support plate, inner casing, cantilever mounting edge and outer casing cavity with potting material.

[0013] Preferably, in step S1, the potting material fills the cavity completely, with its upper end not exceeding the top of the cavity.

[0014] Preferably, the potting material is beeswax.

[0015] Preferably, the tooling includes a base and a cantilever bracket mounted on the base. The base is provided with auxiliary legs, and the auxiliary legs and the cantilever bracket work together to support and clamp the workpiece.

[0016] Compared with the prior art, the beneficial effects of the present invention are: After grinding out the design datum, this invention interchanges the positions of the support and clamping, employs full-surface reverse support, and pre-drills multiple holes on the cantilever bracket that coincide with the positions of the holes to be machined, using the cantilever bracket for reverse clamping; thereby achieving the coincidence of the machining datum and the design datum. (1) The non-tilting processing of the installation edge ensures that the verticality and flatness of the installation edge are qualified; (2) The machining datum and the design datum coincide, ensuring that the accuracy of the dimensions related to the design datum meets the design requirements. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the processing method of a weakly rigid thin-walled single-mounting-side exhaust support according to the present invention.

[0018] Figure 2 This is a schematic diagram of the machining process for a weakly rigid, thin-walled, single-mounting-side exhaust support.

[0019] Figure 3 for Figure 2 AA sectional view.

[0020] Figure 4 This is a top view of the tooling of the present invention.

[0021] The markings in the diagram are explained below: 1. Base; 11. Auxiliary support legs; 2. Cantilever bracket; 3. Workpiece; Filling and potting material at points A, B, and C in the diagram. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0028] Example 1 like Figure 1 The image shows a first embodiment of a processing method for a weakly rigid thin-walled single-mounting-edge venting support according to the present invention, which includes the following steps: S1: Cavity filling: Fill the cavity of workpiece 3 with potting material to increase the overall machining rigidity of workpiece 3; The hollow support plate, inner casing, cantilever mounting edge and outer casing cavity are filled with potting material; Cavity-filling potting materials are an ingenious process that effectively solves the problem of machining deformation in thin-walled structural parts, and also brings additional benefits such as vibration reduction and weight reduction. Specifically: ① Suppressing machining deformation: Liquid or molten potting material is filled into the cavity of the part. After solidification, the material firmly bonds with the inner wall of the cavity, forming a rigid whole, thereby greatly enhancing the rigidity of the entire process system. In this way, during subsequent machining such as turning and milling, it can effectively resist cutting forces, prevent the part from chattering or deforming due to insufficient rigidity, and ensure the final machining accuracy and surface quality. ② Vibration reduction and noise reduction: The potting material itself is a high-molecular polymer or low-melting-point alloy, which can absorb and dissipate vibration energy, acting as a damper. When the engine is operating and generating severe vibrations, the material filled in the cavity structure of the support plate, blades, etc., can effectively reduce the amplitude and noise, and improve the fatigue resistance and life of the component. ③ Weight reduction and efficiency improvement: This technology allows parts to adopt a lighter and thinner "hollow + filled" composite structure. While maintaining rigidity, this structure significantly reduces weight compared to traditional solid structures, contributing to a higher thrust-to-weight ratio in the engine. ④ Simplified Process and Protective Function: The filled "solid" part simplifies clamping and allows for most machining to be completed in one operation, reducing processing steps. Simultaneously, the filler material blocks cavity openings during machining, preventing metal chips from entering, and protects untreated areas during localized surface treatment.

[0029] The potting material fills the entire cavity, but its upper end does not extend beyond the top of the cavity. In one embodiment of the invention, the potting material is beeswax; such as... Figure 3 As shown in the figure, wax is poured at points A, B, and C.

[0030] S2: Rough machining and semi-finishing: Using the single mounting edge of the outer casing as the machining datum, and with the datum having a allowance, material is removed from dimensions unrelated to the datum. Rough machining of the exhaust support of aero-engine is a key stage in the entire manufacturing process. Its core objective is to efficiently remove the workpiece material without causing excessive deformation, thus laying a good foundation for subsequent semi-finishing and finishing. S21: Rough turning datum: Convert the workpiece's three axial and radial datums to the single mounting edge of the outer casing, perform rough machining with the datum having a reserved allowance, and cut the inner casing with a predetermined allowance. First, rough machine the reference surface that will be clamped and positioned in subsequent processes; rough machine the inner and outer surfaces of the main body of the part, leaving a uniform machining allowance: the allowance reserved for the reference is 0.06mm~0.1mm, preferably 0.1mm; S22: CNC vertical machining: The three corners of the workpiece are converted to the reference and placed on the single mounting edge of the outer casing, and the mounting seat on the side wall of the outer casing is machined to the design dimensions; Transforming the angular reference of workpiece 3 to the mounting edge of the outer casing is a crucial step in connecting the cast workpiece 3 with precision machining. The core challenge lies in finding a reliable and uniform machining reference on a large, thin-walled, and easily deformable casting like the casing, to ensure the accuracy of all subsequent processes. S3: Finishing: Grinding the single mounting edge of the outer casing to bring out the design reference; The finishing of the exhaust support is the final step in the entire manufacturing process. The core objective is to ensure stringent design accuracy and surface quality under conditions where the rigidity of workpiece 3 has been significantly weakened. Finishing prepares the workpiece for ultra-precision machining; finishing is performed by grinding the single mounting edge of the outer casing to the design reference using an external cylindrical grinding method. S4: Ultra-precision machining: Use tooling to clamp workpiece 3 in reverse so that the supporting surface is on the upper end face and the pressing surface is on the lower end face. Use the design datum as the machining datum to machine the remaining dimensions. The ultimate goal of ultra-precision machining is to meet all the high-precision requirements on the drawings, including the flatness and parallelism of the mounting edges and the high positional accuracy of the hole system. S41: CNC vertical machining: The machining datum is set at the design datum, and the precision dimensions related to the datum are machined; The precision dimensions related to the reference are located in the outer casing, inner casing, and hollow support plate, specifically the flatness, perpendicularity, and roundness of a single mounting edge, as well as the position of the holes on the end faces of the single mounting edge and the inner casing. S42: Internal grinding: Grinding the precision dimensions of the inner casing based on the design angular datum, surface datum, and radial datum.

[0031] The precision dimensions of the inner casing include the coaxiality of the inner casing and the outer casing, the flatness of the end face of the inner casing, and the inner bore diameter of the inner casing. Ultra-precision machining aims to comprehensively enhance the "surface integrity" of parts. Specific requirements are mainly reflected in the following aspects: Extreme geometric accuracy: Dimensional tolerances are strictly controlled at the micrometer (μm) or even submicrometer (0.1μm) level, and the surface roughness Ra value is far superior to the Ra0.8 of precision machining, consistently reaching below Ra0.4. Surface physical properties: Residual compressive stress with amplitudes as high as -800MPa to -1000MPa is precisely introduced into the part surface to offset harmful tensile stresses generated during service, and to form a hardened layer with a depth of 0.2mm-0.3mm, significantly improving fatigue resistance and wear resistance. Elimination of surface defects: Thoroughly removes defects such as grinding burns, microcracks, and altered layers left by previous processes; these tiny defects are often the source of fatigue cracks. Comprehensive quality assurance: Ensures that parts can operate stably for a long time under the high temperature, high pressure, and high vibration conditions of the engine, while improving the reliability of fit and aerodynamic performance.

[0032] Example 2 The following is a second embodiment of the processing method of a weakly rigid thin-walled single-mounting-side exhaust support of the present invention. This embodiment is similar to embodiment 1, except that the potting material is yellow wax.

[0033] The advantages of beeswax are its low melting point and potting temperature, which is much lower than the heat treatment temperature of the part material, effectively avoiding deformation or changes in structure caused by high temperatures. Its unique "thermal shrinkage and cold expansion" property ensures minimal curing shrinkage, allowing it to fit tightly to the part and provide excellent rigidity.

[0034] Example 3 The following is a second embodiment of the processing method of a weakly rigid thin-walled single-mounting-side exhaust support of the present invention. This embodiment is similar to the first embodiment, except that the tooling includes a base 11 and a cantilever bracket mounted on the base 11. The base 11 is provided with an auxiliary support leg 11. The auxiliary support leg 11 and the cantilever bracket 2 work together to support and press the workpiece 3.

[0035] like Figures 2 to 4 The bottom of the workpiece 3 is supported by the auxiliary support leg 11. The cantilever bracket 2 can be an L-shaped structure. The upper end is inserted into the workpiece 3 and supported from the top of the workpiece 3. The lower end is connected to the base 11. At the same time, the auxiliary support leg 11 and the cantilever bracket 2 work together to press the workpiece 3. This achieves inverted processing, so that the processing datum and the design datum coincide, ensuring that the accuracy of the dimensions related to the design datum meets the design requirements.

[0036] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for manufacturing a weakly rigid thin-walled single-mounting-edge venting support, characterized in that, Specifically, the following steps are included: S1: Cavity filling: Filling the cavities of the workpiece with potting material to increase the overall machining rigidity of the workpiece; S2: Rough machining and semi-finishing: Using the single mounting edge of the outer casing as the machining datum, and with the datum having a allowance, material is removed from dimensions unrelated to the datum. S3: Finishing: Grinding the single mounting edge of the outer casing to bring out the design reference; S4: Ultra-precision machining: The workpiece is clamped in reverse using a tooling fixture, so that the supporting surface is on the upper end face and the pressing surface is on the lower end face. The remaining dimensions are machined using the design datum as the machining datum.

2. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 1, characterized in that, Step S2 is as follows: S21: Rough turning datum: The axial and radial datum of the workpiece are converted to the single mounting edge of the outer casing. Rough machining is performed with the datum having a reserved allowance, and the inner casing is cut with a predetermined allowance. S22: CNC vertical machining: The workpiece angle is converted to the reference point and the mounting edge of the outer casing is transferred, and the mounting base on the side wall of the outer casing is machined to the design dimensions.

3. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 1, characterized in that, In step S21, during rough machining, the allowance reserved for the reference is 0.06mm~0.1mm.

4. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 1, characterized in that, The finishing process in step S3 involves grinding the single mounting edge of the outer casing to the design reference using an external cylindrical grinding method.

5. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 1, characterized in that, Step S4 is as follows: S41: CNC vertical machining: The machining datum is set at the design datum, and the precision dimensions of the outer casing, inner casing, hollow support plate and the datum are machined. S42: Internal grinding: Grinding the precision dimensions of the inner casing based on the design angular datum, surface datum, and radial datum.

6. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 5, characterized in that, The precision dimensions related to the reference in step S41 include the flatness, perpendicularity, and roundness of the single mounting edge, as well as the position of the holes on the single mounting edge and the inner casing end face.

7. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 5, characterized in that, The precision dimensions of the inner casing in step S42 include the coaxiality of the inner casing and the outer casing, the flatness of the end face of the inner casing, and the inner diameter of the inner casing.

8. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 1, characterized in that, The specific steps of step S1 are as follows: filling the hollow support plate, inner casing, cantilever mounting edge and outer casing cavity with potting material.

9. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 8, characterized in that, The potting material is beeswax.

10. The processing method of the weakly rigid thin-walled single-mounting-edge venting support according to claim 1, characterized in that, The tooling includes a base and a cantilever bracket mounted on the base. The base is provided with auxiliary legs, and the auxiliary legs and the cantilever bracket work together to support and clamp the workpiece.

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