Blisk abrasive flow finishing fixture and design method thereof

Abstract

The application discloses a whole blade disc abrasive grain flow finishing clamp and a design method thereof, and the design method comprises the following steps: S1, setting a blade tip gap initial range according to a key size of the whole blade disc, and calculating key parameters of a clamp flow channel; S2, constructing a preliminary three-dimensional model of the clamp by using the data obtained in S1, extracting a flow channel model, and performing fluid mechanics simulation; S3, returning to S1 to change the value of the blade tip gap and the like, and obtaining simulation results under different parameter flow channel structures by S2; S4, screening out a best blade tip gap and a best upper guide vane medium exit and entry upper hole diameter D up ′ from the simulation results of S2 and S3; and S5, updating the parameters of the clamp in S1 according to the best parameters in S4. The design method constructs a three-dimensional model of the clamp based on the key size of the whole blade disc, performs fluid mechanics simulation on the flow channel under conditions of multiple blade tip gap values and upper guide vane medium exit and entry upper hole diameter values, and obtains the clamp which is suitable for the structure size of a machining object and improves machining precision.

Description

Technical Field

[0001] This invention relates to the field of abrasive finishing technology, specifically to an integral bladed disk abrasive finishing fixture and its design method. Background Technology

[0002] Integral bladed disks (IBs) are core components of aero-engines. Their complex configuration and long-term operation under demanding conditions of high temperature, high pressure, and high speed make their surface integrity a crucial factor in the engine's performance and lifespan. Abrasive finishing technology, with its excellent machinability and polishing effect, has become a primary method for improving the surface integrity of integral bladed disks in aero-engines.

[0003] Abrasive flow machining typically requires the design of specialized fixtures based on the finishing requirements of the parts. On the one hand, the abrasive medium is guided to flow over the surface being machined, and on the other hand, the flow characteristics of the machining medium inside the flow channel are controlled by the fixture profile, thereby changing the force exerted by the machining medium on the machined part and improving the machining effect.

[0004] Patent CN207014178U proposes a coupled modular abrasive flow polishing fixture. This fixture employs an upper splitter plate, an outer sleeve, and a lower splitter half-plate combined structure. It also uses constraint modules with coupled curved surfaces to adjust the flow channels of the processing medium through the blade gaps, thereby ensuring the uniformity of the blade surface processing. However, this patent lacks a systematic and quantitative fixture design process for integral bladed disks of different structural dimensions. Especially due to the complex structure, large dimensional variation range, and short upgrade cycle of integral bladed disks, its tooling fixture design suffers from poor versatility, is time-consuming, and costly.

[0005] Patent CN117484389A discloses a high-precision turbine disk tenon and groove fixture device and its design method for abrasive flow machining. The turbine disk tenon and groove fixture device includes a first guide plate, a first support plate, a first shaft cover, a shaft, a cylinder ring, a first guide fluid, and a second guide fluid. The design method for the turbine disk tenon and groove fixture includes the following steps: Step 1: Establish the high-precision turbine disk tenon and groove fixture device for abrasive flow machining using SolidWorks. Step 2: In the geometric structure modeling of ANSYS Workbench 2022 R1, extract the volume from the device in Step 1. Step 3: Perform mesh modeling in ANSYS Workbench 2022 R1. Step 4: In the fluid simulation of ANSYS Workbench 2022 R1, select the multiphase flow model and the viscous model from Step 3 and set the boundary conditions. Step 5: Perform pressure and turbulent kinetic energy analysis of the turbine disk tenon and groove fixture device for high-precision abrasive flow machining using fluid simulation.

[0006] Although the aforementioned design method patent also targets the design of a clamping device, it achieves a three-stage guiding effect by entirely using simulation analysis to design parameters such as the inclination of the guide plate opening for the abrasive flow inlet and outlet, the inclination of the cone surface at the guide point opposite the blade tip, and the distance between the guide clamp and the cross structure. This improves the abrasive flow machining accuracy of the turbine disk tenon groove. The patent's technical solution does not incorporate the structural dimensions of the workpiece itself, making it impossible to design an abrasive flow finishing clamping device that is adapted to the workpiece and truly achieves improved machining accuracy. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an integral bladed disk abrasive finishing fixture in view of the defects of the prior art, and at the same time provide a design method for the finishing fixture.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A jig for finishing an integral bladed disk abrasive flow includes a flow guide support, a clamping part, and a flow channel forming part. The flow guide support includes a lower flow guide disk, an upper flow guide disk, and a support wall on the lower flow guide disk for supporting the upper flow guide disk. The upper flow guide disk has an upper medium inlet / outlet hole, and the lower flow guide disk has a lower medium inlet / outlet hole. The clamping part is located at the center of the flow guide support and includes a fixed support on the lower flow guide disk, a support shaft passing through the fixed support, and a fixed end cap sleeved on the support shaft. The integral bladed disk is located in the space formed by the fixed end cap and the fixed support, and the support shaft is located on the lower flow guide disk. The flow channel forming part includes an upper wall, a middle wall, and a lower wall arranged sequentially along the axial direction of the integral bladed disk. The upper wall is connected to the upper flow guide disk, and the lower wall is connected to the lower flow guide disk. The inner surface of the middle wall is an inclined wall surface, and the inclined wall surface is arranged opposite to the blade tip of the integral bladed disk. An abrasive flow medium flow channel is formed between the flow channel forming part and the clamping part.

[0010] A design method for a single-bladed disk abrasive flow finishing fixture as described above includes the following steps:

[0011] S1. Based on the outer diameter d1 of the blade root channel surface of the integral bladed disk, the outer diameter d2 of the integral bladed disk, the axial chord length c of the blade of the integral bladed disk, and the blade tip inclination angle θ0, the initial value of the tip clearance δ is set. The fixed support height H1, upper wall height H2, middle wall height H3, lower wall height H4, middle wall inclined surface inclination angle θ1, upper wall inner surface diameter D3, middle wall inner surface diameter D4, lower wall inner surface diameter D5, and support wall outer diameter D are calculated. support The diameter D of the upper guide plate medium inlet / outlet hole up The diameter D of the lower guide plate medium inlet / outlet hole down The outer diameter of the upper guide plate is D0; the outer diameter of the lower guide plate is equal to that of the upper guide plate.

[0012] H3 = c;

[0013] H2 = H4 = H1;

[0014] θ1 = θ0;

[0015] D3 = d2 + 2δ;

[0016] D4 = D3 - H3sinθ1;

[0017] D5 = D3 + H3sinθ1;

[0018] d support =1.75~2max(D3,D4,D5)>D M1 ;

[0019] d1 <D up =D down <d2;

[0020] D0 = D support +2ΔL <W M ; ΔL is the width margin of the upper guide plate from the outer periphery of the support wall to the outer periphery of the upper guide plate;

[0021] D M1 W is the diameter of the abrasive cylinder in the abrasive flow mill. M The spacing between the hydraulic cylinders for mold closing in an abrasive flow mill.

[0022] S2. Using the data obtained in S1, construct a preliminary three-dimensional structural model of the fixture, extract the preliminary three-dimensional model of the flow channel, perform fluid dynamics simulation, and obtain preliminary simulation results;

[0023] S3. Return to S1 and change the tip clearance δ and the diameter D of the upper guide plate medium inlet / outlet. up The value of is used to obtain simulation results for different parameter flow channel structures through S2;

[0024] S4. Combining the simulation results of S2 and S3, the optimal tip clearance δ′ and the optimal diameter D of the upper guide plate medium inlet / outlet holes were selected. up ′;

[0025] S5. Based on the optimal tip clearance δ′ and the optimal upper guide plate medium inlet / outlet diameter D up Update the parameters of the fixture in S1.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The fixture of the present invention is designed based on the flow channel characteristics of the blades of the integral bladed disk being machined, and constructs the flow path of the machining medium. It is designed with the principles of equal cross section, vertical symmetry, and easy assembly and disassembly. Based on the structural dimensions of the integral bladed disk, it forms an abrasive flow channel that can significantly improve the machining accuracy of the integral bladed disk.

[0028] The fixture design process is based on the key dimensions of the overall bladed disk. By initially setting the blade tip clearance range and other values, a three-dimensional structural model of the fixture is constructed. Fluid dynamics simulations are performed on the flow channel under various blade tip clearance values ​​and upper guide plate medium inlet and outlet diameter values. The flow field distribution characteristics are evaluated based on the normalized value of the part surface machining capability, i.e., PV value. Based on the simulation analysis results, the parameters of key dimensions such as the upper guide plate medium inlet and outlet diameter and blade tip clearance are optimized to obtain an abrasive flow finishing fixture that can truly adapt to the structural dimensions of the machined object and significantly improve machining accuracy. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the abrasive finishing fixture described in Embodiment 1 of the present invention;

[0030] Figure 2 for Figure 1 Schematic diagram of the structure of the central guide support section;

[0031] Figure 3 for Figure 1 Schematic diagram of the middle clamping part;

[0032] Figure 4 for Figure 1 Schematic diagram of the structure of the central flow channel forming section;

[0033] Figure 5 These are simulation results for different tip clearance parameters in Embodiment 2 of the present invention;

[0034] Figure 6 These are simulation results for different upper guide plate medium inlet / outlet diameter parameters in Embodiment 2 of the present invention;

[0035] Figure 7 The results are the static simulation results of the fixture in Embodiment 2 of the present invention;

[0036] Figure 8 The image shows a comparison of the surface morphology of the test piece before and after abrasive finishing using the fixture designed in Example 2. Detailed Implementation

[0037] To clearly illustrate the technical features of this solution, the following detailed description, in conjunction with the accompanying drawings, will explain the technical solution in detail.

[0038] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0039] Furthermore, it should be understood in the description of this application that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation on this application. In addition, 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 one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0040] In this application, unless otherwise expressly 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, an electrical connection, or a communication 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0041] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an 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 this application. 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 can be combined in any suitable manner in one or more embodiments or examples.

[0042] Example 1

[0043] like Figure 1 The integral bladed disk abrasive flow finishing fixture shown is constructed based on the flow channel characteristics of the blades of the integral bladed disk being machined. The abrasive flow medium flow channel is constructed, and the fixture structure is designed according to design principles such as equal cross-section, vertical symmetry, and convenient assembly and disassembly. The fixture specifically includes a flow guide support part 1, a clamping part 2, and a flow channel forming part 3.

[0044] like Figure 2 As shown, the flow guide support 1 includes a lower flow guide plate 11, an upper flow guide plate 12, and a support wall 13 supporting the upper flow guide plate 12. The upper flow guide plate 12 has an upper medium inlet / outlet hole 121, and the lower flow guide plate 11 has a lower medium inlet / outlet hole 111. During processing, the lower flow guide plate 11 is fixed to the abrasive flow mill, the support wall 13 is installed on the lower flow guide plate 11, and the upper flow guide plate 12 is used to introduce or extract the abrasive flow medium into or out of the fixture. The flow guide support 1 as a whole bears the load generated when the abrasive flow mill is closed, preventing the machined integral impeller from deforming under load.

[0045] like Figure 3 The clamping part 2 shown is located at the center of the flow guide support part 1 and is used to clamp and position the integral impeller A. It includes a fixed support 21, a fixed end cover 22, a support shaft 23, a locking nut 24, and a positioning pin 25. The fixed support 21 is fixed on the lower flow guide plate 11, and the support shaft 23 passes through the fixed support 21. The integral impeller A is set on the fixed support 21 through the support shaft 23. The fixed end cover 22 is sleeved on the support shaft 23 and pressed against the integral impeller A by the locking nut 24. The support shaft 23 cooperates with the lower flow guide plate 11, the fixed support 21, and the fixed end cover 22 to achieve radial positioning and fixation. The positioning pin 25 cooperates with the angular positioning hole of the integral impeller to achieve circumferential positioning.

[0046] like Figure 4 As shown, the flow channel forming part 3 includes an upper wall 31, a middle wall 32, and a lower wall 33 arranged sequentially along the axial direction of the integral bladed disk. The upper wall 31 is connected to the upper guide plate 12, and the lower wall 33 is connected to the lower guide plate 11. Generally, the flow channel forming part 3 can be designed as an integral component. In this embodiment, adhering to the principles of convenient assembly and disassembly and easy maintenance, the upper wall 31, the middle wall 32, and the lower wall 33 are set independently and connected into one piece by a stop fit. The inner surface of the middle wall 32 is an inclined wall surface arranged opposite to the blade tip of the integral bladed disk.

[0047] An abrasive flow medium channel is formed between the flow channel forming part 3 and the clamping part 2. The fixture structure of this embodiment is simple and easy to assemble.

[0048] Example 2

[0049] This embodiment details the dimensional design of the integral bladed disk abrasive finishing fixture in Embodiment 1. The following dimensions of the integral bladed disk itself are merely examples and do not constitute a limitation on the dimensions of the workpiece. The specific steps are as follows:

[0050] S1. See also Figure 3 The outer diameter D1 of the fixed support 21 and the outer diameter D2 of the fixed end cover 22 are determined according to the outer diameter d1 of the flow channel surface at the root of the integral bladed disk being machined.

[0051] D1 = D2 = d1 = 110mm

[0052] The height H1 of the fixed support 21 is based on the distance h from the positioning end face of the integral impeller to the bottom surface of the impeller and the depth L of the fixing bolt holes on the bottom surface of the fixed support 21. s And the height margin Δh of the fixed support 21 is determined, Δh is generally taken as 10~15mm:

[0053] H1 = h + L s +Δh=(26.95+15+(10~15))mm=(51.95~56.95)mm

[0054] The height of the fixed support 21 is set to H1 = 52mm.

[0055] See Figure 4 The height H3 of the middle wall 32 is determined based on the axial chord length c of the blade of the impeller disk:

[0056] H3 = c = 25.87 mm

[0057] The height of the middle wall 32 is selected as H3 = 30mm.

[0058] The height H4 of the lower wall 33 is flush with the height H1 of the fixed support 21. To enable bidirectional machining, the height H2 of the upper wall 31 is equal to the height H4 of the lower wall 33.

[0059] H2 = H4 = H1 = 52mm

[0060] The inner surface of the middle wall 32 is an inclined wall structure coupled with the blade tip envelope, and its wall inclination angle θ1 is equal to the blade tip inclination angle θ0 of the overall bladed disk blade:

[0061] θ1 = θ0 = 11.9°

[0062] The inner surface diameters D3, D4, and D5 of the upper wall 31, middle wall 32, and lower wall 33 are determined based on parameters such as the outer diameter d2 of the integral bladed disk being machined and the blade tip clearance δ. The value range of the blade tip clearance δ is set to 2–10 mm.

[0063] D3=d2+2δ=(181.9+2×(2~10))mm=(185.9~201.9)mm

[0064] D4=D3-H3sinθ1=((185.9~201.9)-30×sin11.9°)mm=(179.7~195.7)mm

[0065] D5=D3+H3sinθ1=((185.9~201.9)+30×sin11.9°)mm=(192.1~208.1)mm

[0066] The height of the mating stop between the upper wall 31, the middle wall 32, and the lower wall 33 is selected to be 5mm.

[0067] The initial value range of the blade tip clearance δ is set based on existing research experience. When the clearance is too large, it will increase the flow channel area of ​​the outer region of the blade, reduce the proportion of abrasive flowing through the blade, and reduce processing efficiency. In this embodiment, the blade tip clearance is initially selected as δ = 6 mm. Therefore, the inner surface diameters of the upper wall 31, middle wall 32, and lower wall 33 are selected as D3 = 193.9 mm, D4 = 187.7 mm, and D5 = 200.1 mm, respectively.

[0068] See Figure 2 Support wall 13 outer diameter D support The selection should be based on the reserved installation space for the upper wall 31, middle wall 32, and lower wall 33. Therefore, its size is set to 1.75 to 2 times the maximum value among the inner surface diameters of the upper wall 31, middle wall 32, and lower wall 33 (this multiple range is an empirical value proposed considering the basic dimensions of the upper wall, middle wall, and lower wall and the range of operable space), and is also larger than the diameter D of the abrasive cylinder of the abrasive flow machine tool. M1 To ensure effective bearing of the clamping force:

[0069] D support =1.75~2max(D3,D4,D5)=1.75~2×max(187.7,193.9,200.1)mm

[0070] =350.2~400.2mm

[0071] D support >D M1 =150mm

[0072] The outer diameter of the support wall 13 is selected as D. support =350mm. If D is calculated... support <D M1 When the outer diameter of the support wall 13 is D, then D is taken as the outer diameter of the support wall 13. M1 .

[0073] Upper guide plate 12 Medium inlet / outlet upper hole 121 Diameter D up Lower guide plate 11, medium inlet / outlet lower hole 111, diameter D down Determined based on the outer diameter d2 of the overall bladed disk and the outer diameter d1 of the blade root flow channel surface:

[0074] d1 = 110mm <D up =D down <d2=181.9mm

[0075] D was initially selected. up =D down =150mm.

[0076] The outer diameter D0 of the upper guide plate 12 should ensure easy assembly and disassembly of the fixture. ΔL is the width allowance of the upper guide plate 12 from the outer periphery of the support wall 13 to the outer periphery of the upper guide plate 12, usually taken as 25-30mm. Meanwhile, the outer diameter D0 of the upper guide plate 12 must be smaller than the spacing W of the clamping hydraulic cylinders of the abrasive flow machining center. M To ensure the fixture can be used normally on the abrasive flow machining center, the mold contact area ratio λ should be verified to be greater than 0.5 to guarantee sealing during machining.

[0077] D0 = D support +2ΔL=(350+2×(25~30))mm=(400~410)mm <W M =600mm

[0078] The outer diameter of the upper guide plate 12 is selected as D0 = 400mm, and the outer diameter of the lower guide plate 11 is equal to that of the upper guide plate 12.

[0079] Mold contact area ratio S contact S represents the mold closing contact area. M S represents the end face area of ​​the abrasive cylinder. M It is a definite value, but S contact The value of D will vary. up And D0 changes, therefore we have:

[0080]

[0081] In the above formula, D M2 D is the outer diameter of the abrasive cylinder end face flange. M2 =240mm. Based on the aforementioned selected D up =150mm, D M1 =150mm, D0=400mm, there is

[0082] D up ≤D M1 <D M2 ≤D0

[0083] Substitute D0 into the mold contact area ratio calculation:

[0084]

[0085] To meet the rigidity and strength requirements, the thickness H5 of the upper guide plate 12 is ≥20mm, and the thickness of the lower guide plate 11 is equal to that of the upper guide plate 12, both being 20mm; at the same time, the total height H0 of the fixture is less than the maximum working height H of the abrasive flow machining center. M ,Right now

[0086] H0=H2+H3+H4+2H5=(52+30+52+2×20)mm=174mm <H M=260mm

[0087] Both the upper guide plate 12 and the lower guide plate 11 are fitted with stop edges to fit the upper wall 31 and the lower wall 33 respectively, with a stop edge height of 5mm.

[0088] S2. Using the data obtained in S1, construct a preliminary three-dimensional structural model of the fixture based on Solidworks three-dimensional modeling software, extract the three-dimensional model of the internal flow channel, import it into Fluent fluid dynamics simulation software, first generate the finite element model mesh, use Poly-Hexcore hexahedral mesh to mesh the geometry of the finite element model, generate the three-dimensional flow channel finite element model, and finally set the flow model, fluid parameters and boundary conditions to perform fluid simulation.

[0089] The RNG k-ε model was selected for the flow model; the fluid configuration adopted a mixed multiphase flow model, in which SiC particles were selected for the solid phase, and a custom liquid material was selected for the liquid phase. The viscosity-shear rate curve was set using the CarreauYasuda model.

[0090] S3. Return to S1 and change the tip clearance δ and the diameter D of the upper guide plate 12 medium inlet / outlet orifice 121. up The value of is determined by obtaining simulation results for different parameter flow channel structures through S2.

[0091] Blade tip clearance δ, upper guide plate 12, medium inlet / outlet upper hole 121, diameter D up The value schemes are shown in Table 1 and Table 2 respectively:

[0092] Table 1. Screening scheme for different tip gap parameters

[0093]

[0094] Table 2. Screening scheme for different upper guide plate medium inlet / outlet diameter parameters

[0095]

[0096] S4. Combining the simulation results of S2 and S3, the optimal tip clearance δ′ and the optimal diameter D of the upper guide plate 12 medium inlet / outlet orifice 121 were selected. up ′.

[0097] Different blade tip clearances δ and the diameter D of the upper guide plate 12 medium inlet / outlet orifice 121 are used. upThe flow field distribution characteristics of the selected values ​​are compared, and the evaluation of these characteristics is mainly based on the surface machining capability of the parts. According to the Preston equation, the amount of material removed from the surface of a part is proportional to the product of the surface pressure P and the near-wall velocity V, i.e., the PV value. Furthermore, to compare the distribution patterns of material removal under different flow channel structures, the normalized value of PV is usually taken as the main evaluation parameter for the flow field distribution characteristics.

[0098]

[0099] Where: PV i For any sampling point, the PV value is... This is the normalized value of the PV at that point; n is the total number of sampling points.

[0100] By extracting the surface pressure P and near-wall velocity V at sampling points on the blade back profile and blade basin profile of a specific wall surface from simulation results under different flow channel structures, the PV value is calculated, and the normalized distribution of the PV value is obtained. These values ​​are then compared with the initial flow channel structure to select the optimal blade tip clearance δ′ and the optimal upper guide plate medium inlet / outlet diameter Dup'.

[0101] Simulation results for different tip clearance parameters are as follows: Figure 5 As shown, based on the problem of weak processing capability in the area near the blade root during abrasive flow machining, a design scheme with a higher proportion of PV normalized value in the area near the blade root is selected. At the same time, considering that an excessively small blade tip gap can easily cause blade collision damage during the actual assembly and disassembly of the overall bladed disk, the blade tip gap δ′=3mm is selected as the optimal parameter.

[0102] Simulation results for different diameter parameters of the upper guide plate 12 medium inlet / outlet upper hole 121 are as follows: Figure 6 As shown, based on the problem of difficult machining of the blade root region in the current abrasive flow machining process, a small-diameter fixture design is adopted. At the same time, considering that an excessively small diameter of the upper guide plate 12 medium inlet / outlet upper hole 121 would cause excessive flow resistance and excessive machining energy loss, thus reducing machining efficiency, a design scheme with a diameter Dup' of 150mm for the upper guide plate 12 medium inlet / outlet upper hole 121 was selected, which is consistent with the initial parameters.

[0103] S5. Based on the optimal tip clearance δ′ and the optimal diameter D of the upper guide plate 12 medium inlet / outlet orifice 121... up Return to S1 to update the fixture parameters and optimize the fixture.

[0104] Adjust the fixture dimensions based on the optimal parameter δ′=3mm:

[0105] The inner surface diameter D3 of the middle wall 32 is adjusted to: D3=d2+2δ′=(181.9+2×3)mm=187.9mm

[0106] The inner surface diameters D2 and D4 of the upper wall 31 and the lower wall 33 are adjusted as follows:

[0107] D4=D3-H3sinθ1=(187.9-30×sin11.9°)mm=181.7mm

[0108] D5=D3+H3sinθ1=(187.9+30×sin11.9°)mm=194.1mm

[0109] Support wall 13 outer diameter D support Adjusted to:

[0110] D support =1.75~2max(d3,D4,D5)=1.75~2×max(181.7,187.9,194.1)mm

[0111] =339.7~388.2mm

[0112] The outer diameter of support wall 13 is selected as D. support =340mm.

[0113] The remaining dimensions remain at their initial values ​​and still meet the design requirements.

[0114] S6: Ansys structural mechanics simulation is used to perform static analysis on the optimized fixture structure to obtain the stress and strain distribution under loads such as clamping force of the fixture cylinder and abrasive pressure, and compare it with the yield limit stress of the fixture material to confirm whether the fixture strength is qualified.

[0115] The 3D model of the fixture assembly, optimized for external dimensions and built in Solidworks, was imported into the Static Structural module of Ansys-Workbench for static structural mechanics simulation. The fixture's bottom surface is subject to fixed support, while the top surface bears the clamping force load applied by the abrasive flow machine tool, with a load magnitude of 1800 PSI and a direction perpendicular to the top surface downwards. The fixture's flow channel walls bear the pressure of the machining medium, with a load magnitude of 200 PSI and a direction normal to the wall surface.

[0116] Static structural mechanics simulation results are as follows Figure 7 As shown: The area of ​​maximum deformation of the fixture is mainly located in the area where the flow channel inlet is located on its top surface, that is, the area where the abrasive flow machine tool clamping force is borne, and its maximum equivalent stress σ max = 46.38 MPa, which satisfies:

[0117] n s σ max =2.0×46.38MPa=92.75MPa<σ s =355MPa

[0118] Where: n s For plastic materials, the safety factor is σ. s The yield strength of 45 steel, the material selected for the fixture.

[0119] As can be seen from the above, the optimized fixture has the strength required for use.

[0120] If the structural static simulation analysis fails to meet the strength requirements, return to S1 to adjust the outer diameter D of the support wall. support With the outer diameter D0 of the upper guide plate remaining unchanged, the three-dimensional model is reconstructed and structural statics simulation is performed until the strength meets the requirements.

[0121] S7: Fabricate an abrasive flow finishing fixture and combine it with a simplified test piece of the integral bladed disk to be machined for abrasive flow machining experiments.

[0122] A fixture was developed based on the optimized and screened structural parameters. A simplified bladed disk model test piece was designed according to the material, structure, and size of the integral bladed disk to be processed. The simplified bladed disk adopts a detachable simplified blade-tenon structure. The simplified blade is made of the same TC4 alloy as the integral bladed disk to be processed, and is connected to the tenon with a dovetail groove structure to achieve circumferential and radial clamping and positioning of the simplified blade. The purpose is to ensure that the blade is replaceable and effectively reduce the processing cost of repeated tests.

[0123] S8: Inspect the surface quality and dimensional accuracy of the processed test piece to confirm whether the fixture meets the requirements for abrasive flow processing of the integral bladed disk. Otherwise, change the value of the blade tip clearance δ and start all steps again from the aforementioned S1.

[0124] The developed abrasive flow fixture was combined with a simplified impeller. The abrasive material selected was SiC with a mesh size of 80. # The abrasive grains were mixed at a 1:1 ratio for abrasive flow finishing tests, with an inlet pressure of 200 PSI. During assembly, the machined integral impeller could be precisely and stably clamped in the fixture, and the assembly process was convenient and unlikely to cause collisions. During the test, the fixture effectively withstood the clamping force of the abrasive flow machine tool, and its structure had strong sealing properties, with no abrasive leakage observed.

[0125] The test results are as follows Figure 8 As shown, the surface roughness of the simplified blade decreased from Ra 0.87 μm to Ra 0.40 μm with the continuous increase of the number of machining cycles, and the surface quality was significantly improved.

[0126] Example 3

[0127] The difference between this embodiment and Embodiment 2 is that the outer diameter of the support wall 13 is selected as D. support =400mm, and the rest of the design process is completely consistent with Example 2.

[0128] Obviously, the above embodiments are merely examples to clearly illustrate the technical solutions of 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 jig for integral bladed disk abrasive finishing, characterized in that, The device includes a flow guide support, a clamping part, and a flow channel forming part. The flow guide support includes a lower flow guide plate, an upper flow guide plate, and a support wall on the lower flow guide plate for supporting the upper flow guide plate. The upper flow guide plate has an upper medium inlet / outlet hole, and the lower flow guide plate has a lower medium inlet / outlet hole. The clamping part is located at the center of the flow guide support and includes a fixed support on the lower flow guide plate, a support shaft passing through the fixed support, and a fixed end cap sleeved on the support shaft. The integral impeller is located in the space formed by the fixed end cap and the fixed support, and the support shaft is located on the lower flow guide plate. The flow channel forming part includes an upper wall, a middle wall, and a lower wall arranged sequentially along the axial direction of the integral impeller. The upper wall is connected to the upper flow guide plate, and the lower wall is connected to the lower flow guide plate. The inner surface of the middle wall is an inclined wall surface, and the inclined wall surface is arranged opposite to the blade tip of the integral impeller. An abrasive flow medium flow channel is formed between the flow channel forming part and the clamping part. The design method for the integral bladed disk abrasive flow finish fixture includes the following steps: S1. Based on the outer diameter of the blade root flow channel surface of the integral bladed disk Overall bladed disk outer diameter Axial chord length of integral bladed disk Leaf tip angle Set the blade tip gap Initial values ​​were determined, and the height of the fixed support was calculated. Upper wall height Middle wall height Lower wall height Inclined wall angle , upper wall inner surface diameter Diameter of the inner surface of the middle wall , lower wall inner surface diameter Outer diameter of support wall Diameter of the upper guide plate medium inlet / outlet hole Diameter of the lower guide plate medium inlet / outlet Outer diameter of upper guide plate The outer diameter of the lower guide plate is equal to the outer diameter of the upper guide plate. ； ； ； ； ； ； ； ； ; This refers to the width margin of the upper guide plate from the outer periphery of the support wall to the outer periphery of the upper guide plate. The diameter of the abrasive cylinder in the abrasive flow mill tool; The spacing between the hydraulic cylinders for mold closing in an abrasive flow mill. S2. Using the data obtained in S1, construct a preliminary three-dimensional structural model of the fixture, extract the preliminary three-dimensional model of the flow channel, perform fluid dynamics simulation, and obtain preliminary simulation results; S3. Return to S1 and change the tip clearance. Diameter of the upper guide plate medium inlet / outlet hole The value of is used to obtain simulation results for different parameter flow channel structures through S2; S4. Combining the simulation results from S2 and S3, the optimal tip clearance is selected. With the optimal upper guide plate medium inlet / outlet diameter ; S5. Based on the optimal tip clearance With the optimal upper guide plate medium inlet / outlet diameter Update the parameters of the fixture in S1.

2. The integral bladed disk abrasive finishing fixture according to claim 1, characterized in that, The upper wall, middle wall, and lower wall are fitted together by a stop joint.

3. The integral bladed disk abrasive finishing fixture according to claim 1, characterized in that, S4 in and The optimal value is obtained by extracting the surface pressure at sampling points on the underside and base of the blade. P Near-wall flow velocity V ,calculate PV Value, get PV The distribution of the normalized values ​​is evaluated.

4. The integral bladed disk abrasive finishing fixture according to claim 1, characterized in that, Outer diameter of upper guide plate The value of must satisfy the sealing requirements of the abrasive flow machining tool's mold closing process, that is: Mold contact area ratio ; This refers to the contact area during mold closing. This refers to the end face area of ​​the abrasive cylinder; This refers to the outer diameter of the flange on the end face of the abrasive cylinder.

5. The integral bladed disk abrasive finishing fixture according to claim 1, characterized in that, A three-dimensional model of the fixture is constructed using the data obtained from S5, and static structural mechanics simulation is performed to confirm whether the fixture's strength is up to standard. If it is not up to standard, the outer diameter of the support wall in S1 needs to be adjusted. and the outer diameter of the upper guide plate Take the value, keep the other parameters unchanged, reconstruct the 3D model of the fixture and perform static structural mechanics simulation until the strength meets the requirements.

6. The integral bladed disk abrasive finishing fixture according to claim 5, characterized in that, Fabricate an abrasive flow finishing fixture, conduct abrasive flow machining tests, and inspect the surface quality and dimensional accuracy of the machined test pieces to confirm whether the fixture meets the requirements for abrasive flow machining of integral bladed disks; otherwise, replace the blade tip clearance. Get the value and re-execute S1 to S5.

7. The integral bladed disk abrasive finishing fixture according to claim 1, characterized in that, Leaf tip gap The initial value range is 2~10mm.

8. The integral bladed disk abrasive finishing fixture according to claim 1, characterized in that, upper guide plate thickness .

9. The integral bladed disk abrasive finishing fixture according to claim 8, characterized in that, The thickness of the lower guide plate is equal to the thickness of the upper guide plate, and the total height of the fixture is... , This is the maximum working height of the abrasive flow machine tool.

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