Vibration excitation polishing method for airfoil diffuser finishing

Abstract

The application discloses a kind of exciting vibration and polishing machining methods for aviation diffuser finishing machining, comprising the following steps: analyzing the structural characteristics and processing requirements of aviation diffuser parts, determining the size of main vibration body container and particle medium size;According to the part structure characteristics, design radial profiling protection and axial profiling protection, to form the subjective combination wall structure with diffuser parts assembly;Using tool clamp, the subjective combination wall structure is installed in the main vibration body container, and a certain amount of particle medium and liquid medium are added;The installation angle and frequency of two main vibration body motors, and the frequency of two vibration isolation body motors are set;After processing, the aviation diffuser part is taken out, ultrasonic cleaning and detecting processing effect.The method of the application not only prevents the blade tip area from being polished too much and enhances the action characteristics of the particle medium on the runner, but also effectively removes the milling texture of the blade and runner surface, reduces the surface roughness, and realizes high-efficiency and high-quality finishing machining of the parts.

Description

Technical Field

[0001] This invention relates to the field of surface processing technology for high-performance parts of aero-engines, and in particular, to a vibratory polishing method for finishing aero-engine diffusers. Background Technology

[0002] The aircraft diffuser is a crucial transitional component connecting the compressor and the combustion chamber. Its core functions include changing the airflow direction and converting velocity energy into pressure energy to provide conditions for stable combustion in the combustion chamber. Due to its long-term operation under high pressure and high temperature, it often utilizes materials such as high-temperature alloys and titanium alloys, and its overall structure is complex with high machining precision requirements. Currently, integral diffusers, due to irregular slopes on the bottom surface of the flow channel or three-dimensional irregular blades, require five-axis milling, resulting in milling marks and high surface roughness after machining. Research shows that the surface integrity of the diffuser directly affects the engine's performance and lifespan. Existing manual polishing relies heavily on worker experience and skills, and is inefficient, labor-intensive, and produces inconsistent quality. Therefore, there is an urgent need to develop new finishing technologies to meet the surface integrity polishing requirements.

[0003] In the tumbling finishing process, discrete particulate media exhibit good shape adaptability. It offers significant advantages in reducing surface roughness and in the synergistic polishing of complex flow channels and curved surface structures, and has been used to process key aero-engine components such as integral bladed disks and blades. However, over-polishing of the blade tip region is prone to occur during the polishing process. Currently, there is no research on tumbling finishing technology specifically for diffusers. Furthermore, thinner leading and trailing edges can easily lead to increased tip radius and compromised surface accuracy, thus affecting the performance of aero-engines.

[0004] To address this issue, this application proposes a four-mass active vibration polishing method for the finishing of diffuser walls in aircraft diffusers. The aim is to effectively remove milling textures and reduce surface roughness values ​​of diffuser blades and flow channels without compromising the surface accuracy of the diffuser blades. Summary of the Invention

[0005] This invention provides a vibratory polishing method for finishing aircraft diffusers, which solves the technical problems that occur when using existing roller grinding finishing machines, such as over-polishing of the blade tip area and the thin leading and trailing edges leading to increased blade tip radius and damage to surface accuracy, thereby affecting the performance of aero engines.

[0006] The technical solution adopted in this invention is as follows: A vibratory polishing method for finishing aircraft diffusers includes the following steps: S10: Analyzing the structural characteristics and processing requirements of the aircraft diffuser parts to determine the inner cavity dimension D0 and particle medium dimension d of the main vibrating body container used for vibratory polishing of the parts on the vibratory polishing device; S20: Designing radial and axial contouring protective components based on the structural characteristics of the aircraft diffuser parts, so as to assemble them with the diffuser parts to form a combined subjective and objective device wall structure to control the particle medium flow field; S30: Installing and fixing the combined subjective and objective device wall structure using tooling fixtures. In the inner cavity of the main vibrating body container, a certain amount of particulate medium and liquid medium are added; S40 sets the installation angle φ and frequency f1 of the two main vibrating body motors on both sides of the main vibrating body container, and sets the frequency f2 of the two vibration isolation body motors on the vibration isolation body arranged below the main vibrating body container, so that the particulate medium couples to form a multidimensional composite vibration flow field under the active excitation of the vibration polishing device, thereby processing the flow channel and blade profile of the aerospace diffuser parts; S50 after processing, the aerospace diffuser parts are taken out, ultrasonically cleaned and the processing effect is tested.

[0007] Furthermore, in step S10, to prevent particulate media from clogging the flow channels of the aerospace diffuser components, the equivalent diameter d of the particulate media should satisfy the following inequality: In the formula, W0 is the minimum width of the radial or axial blade flow channel of the aircraft diffuser component; α is the geometric compatibility coefficient, which is generally taken as 0.2 to 0.3.

[0008] Furthermore, in step S10, to ensure good fluidity of the particulate medium within the inner cavity of the main vibrating body container, the inner cavity diameter D0 of the main vibrating body container should satisfy the following inequality: In the formula, D1 is the maximum diameter of the aerospace diffuser component; δ is the minimum spacing to ensure the flowability of the particulate medium, and .

[0009] Furthermore, the aircraft diffuser component is in the shape of an annular cover, with several radial blades evenly distributed circumferentially on the end face of the cover and several axial blades evenly distributed circumferentially on the outer circumferential surface of the cover opening; the radial contouring protective component includes a vertically intersecting upper mounting plate and a mounting post, the mounting post being used to vertically pass through the central shaft hole of the aircraft diffuser component to vertically mount the aircraft diffuser component along the axial direction; the upper mounting plate is horizontally spaced above the cover end of the aircraft diffuser component, and the lower end of the upper mounting plate is concavely machined to form a stepped annular surface, and several radial contouring blades corresponding to several radial blades are provided circumferentially on the stepped annular surface, and each radial contouring blade has a vertically positioned limiting piece at its cantilever end that extends to the outer side of the corresponding radial blade tip below.

[0010] Furthermore, the axial contouring protective component includes a lower mounting plate and a connecting plate arranged sequentially in the axial direction; after the mounting column vertically passes through the central shaft hole of the aircraft diffuser part, its bottom end presses the flange of the aircraft diffuser part's cover end onto the lower mounting plate. The connecting plate is used to support and fix it on the tooling fixture below, and the axial contouring protective component, the aircraft diffuser part, and the radial contouring protective component are detachably fixed by bolts passing through the connecting plate, the flange of the aircraft diffuser part's cover end, and the mounting column; the lower mounting plate has several axial contouring blades arranged in a circumferential direction corresponding to several axial blades, and the several axial contouring blades connect to the lower mounting plate to form an upward-facing bottom cover, which is used to radially and spacedly fasten to the outside of the cover end of the aircraft diffuser part.

[0011] Furthermore, the widths of both the radial and axial profiled blades must satisfy the following inequality: In the formula, W2 is the actual width of the radial and axial blades of the aircraft diffuser component; δ1 is the single-sided assembly positioning error between the radial or axial profiled blade and the aircraft diffuser component, with a value range of 0.5 to 0.8 mm; A1 is the equivalent displacement amplitude of the oscillation around the Z-axis applied by the excitation polishing device to the main vibrating body container, with a value range of 2 to 4 mm; λ is the vibration randomness compensation coefficient, with a value range of 0.7 to 0.9.

[0012] Furthermore, the installation and clearance design of the radial and axial profiled blades must meet the incident angle conditions, specifically including the vertical clearance L and the lateral overhang S. The vertical clearance L between the radial profiled blade and the corresponding radial blade, and the vertical clearance L between the axial blade and the upper surface of the lower mounting plate, must both satisfy the following inequality: In the formula, β is the damping safety factor, ranging from 0.6 to 0.8; d is the equivalent diameter of the particulate medium; in addition, the lateral overhang S between the radial blade tip and the corresponding limiting plate, and the lateral overhang S between the axial blade tip and the corresponding axial contour blade, must satisfy the following inequality with respect to the vertical clearance L: In the formula, θ is the maximum incident angle of the particulate medium on the blade tip region, and its value is no greater than 20°.

[0013] Furthermore, in step S30, the tooling fixture is a long strip-shaped structure with multiple hexagonal countersunk screw mounting holes along its length to achieve a detachable and fixed connection between the main and objective assembly wall structure; in step S30, the distance between the total filling height of the particulate medium in the inner cavity of the main vibrating body container and the highest point of the main and objective assembly wall structure is... In step S30, the liquid medium is a mixture of grinding slurry with a pH value greater than 7 and water.

[0014] Furthermore, the installation height H0 of the subjective and objective combiner wall structure should satisfy the following inequality: In the formula, H0 is the vertical installation height of the geometric center of the main and objective combined structure wall relative to the bottom of the main vibrating body container; H1 is the total filling height of the particulate medium in a static state; γ1 and γ2 are the flow field energy level distribution coefficients, where the value of γ1 ranges from 0.3 to 0.5; the value of γ2 ranges from 0.6 to 0.8, and γ1 < γ2.

[0015] Further, in step S40, the installation angle φ of the two main vibrating body motors on the main vibrating body container is set to 0°~30°, and the frequency f1 is set to 0~25 Hz; the frequency f2 of the two vibration isolation body motors on the vibration isolation body is set to 0~50 Hz.

[0016] The present invention has the following beneficial effects: This invention proposes an active vibration polishing method for the finishing of aerospace diffusers. This method incorporates radial and axial contouring protective components to form a combined subjective and objective structure with the aerospace diffuser parts. This not only prevents over-polishing of the blade tips in both the axial and radial directions but also enhances the effect of the particulate medium on the flow channel, thus improving the processing efficiency. Furthermore, by adjusting the installation angle and frequency of the two main vibrating motors on the main vibrating body container and the frequency of the two vibration isolation motors on the vibration isolation body, complex three-dimensional composite motion is provided to the container. This allows the particulate medium to collide, roll, and rub against the aerospace diffuser parts. Without compromising the blade profile accuracy, this effectively removes milling textures from the blades and flow channel profiles of the aerospace diffuser, reduces surface roughness, and ultimately achieves efficient and high-quality finishing of the aerospace diffuser parts.

[0017] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart of a preferred embodiment of the vibratory polishing method for finishing aircraft diffusers according to the present invention. Figure 2 This is a schematic diagram of the vibratory polishing device. Figure 3 A schematic diagram showing the spatial structure of an aircraft diffuser component and two enlarged lead-out points; Figure 4 This is a schematic diagram showing the spatial structure and partial enlarged outline of the radial contouring protective component. Figure 5 This is a schematic diagram showing the spatial structure and partial enlarged outline of the axial contour-following protective component. Figure 6 A schematic diagram showing the positional relationship between aircraft diffuser components and the main vibrating body container; Figure 7 This is a schematic diagram of the tooling fixture structure; Figure 8 This is an enlarged schematic diagram showing the assembly clearance and partial outline of the aircraft diffuser components with radial and axial contoured protective parts. Figure 9 The structural diagram of the aircraft diffuser prototype before machining and several lead-out diagrams; Figure 10 The structure of the machined aircraft diffuser prototype and several lead-out diagrams; Figure 11 Figure 1 shows the changes in surface roughness and rate of decrease in different areas of an aircraft diffuser component during machining. Figure 12 Comparison of surface morphology before and after machining of different areas of an aircraft diffuser component.

[0019] Legend: 1. Vibration polishing device; 2. Main vibrating body container; 201. Main vibrating body motor; 3. Particulate media; 4. The wall structure of the subjective and objective combiner; 401. Radial contouring protective component; 4011. Upper mounting plate; 4012. Mounting post; 4013. Radial contouring blade; 4014. Limiting plate; 402. Aircraft diffuser parts; 403. Axial contouring protective component; 4031. Lower mounting plate; 4032. Connecting plate; 4033. Axial contouring blade; 5. Tooling and fixtures; 6. Vibration isolator; 601. Vibration isolator motor. Detailed Implementation

[0020] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] Those skilled in the art will understand that, unless specifically stated otherwise, the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, components, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or combinations thereof. It should be understood that when we say a component is "connected" to another component, it can be directly connected to the other component or connected via an intermediate component. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items. The terms "first" and "second," etc., in this specification and claims are used to distinguish different objects, not to describe a particular order.

[0022] Reference Figure 1 and Figure 2 A preferred embodiment of the present invention provides a vibratory polishing method for finishing aircraft diffusers, comprising the following steps: S10: Analyze the structural features and processing requirements of the aircraft diffuser part 402 to determine the inner cavity size D0 of the main vibrating body container 2 used for vibratory polishing of the part on the vibratory polishing device 1 and the size d of the particulate medium 3, so that the particulate medium 3 has a high processing efficiency for the aircraft diffuser part 402, while also ensuring good flowability of the particulate medium 3 in the flow channel. S20: Based on the structural characteristics of the aircraft diffuser component 402, radial contouring protection component 401 and axial contouring protection component 403 are designed to assemble with the diffuser component to form a subjective and objective combined device wall structure 4 to regulate the flow field of particulate medium 3, thereby avoiding over-throwing in areas such as blade tips. At the same time, the radial contouring protection component 401 and axial contouring protection component 403 enhance the device wall effect to improve the processing effect of particulate medium 3 on the flow channel. S30: The objective and subjective combiner wall structure 4 is installed and fixed in the inner cavity of the main vibrating body container 2 using tooling fixture 5, and a certain amount of particulate medium 3 and liquid medium are added to the inner cavity. S40: Set the installation angle φ and frequency f1 of the two main vibrating motors 201 on both sides of the main vibrating body container 2, and set the frequency f2 of the two vibration isolation motors 601 on the vibration isolation body 6 below the main vibrating body container 2, so that the particulate medium 3 is coupled to form a multi-dimensional composite vibration flow field under the active excitation of the vibration polishing device 1, and exhibits a high-energy fluidization state, thereby performing radial collision, rolling, and sliding processing on the flow channel and blade profile of the aerospace diffuser part 402, thereby reducing surface roughness and improving surface morphology; S50: After processing, remove the aircraft diffuser part 402, perform ultrasonic cleaning, and inspect the processing effect.

[0023] This invention proposes an active vibration polishing method for finishing aerospace diffusers. In this method, radial contouring protection components 401 and axial contouring protection components 403 are designed to form a combined subjective and objective device wall structure 4 with the aerospace diffuser part 402. This not only prevents over-polishing of the tip areas of the axial and radial blades but also enhances the effect of the particulate medium 3 on the flow channel, thereby improving the processing effect. Furthermore, by adjusting the installation angle and frequency of the two main vibrating motors 201 on the main vibrating body container 2 and the frequency of the two vibration isolation motors 601 on the vibration isolation body 6, complex three-dimensional composite motion is provided to the container. This allows the particulate medium 3 to collide, roll, and rub against the aerospace diffuser part 402, effectively removing milling textures and reducing surface roughness without compromising the blade profile accuracy of the aerospace diffuser part. This effectively achieves efficient and high-quality finishing of the aerospace diffuser part 402.

[0024] Optionally, step S10 specifically includes the following steps: S101: Analyze the structural features and processing requirements of aircraft diffuser part 402. For example... Figure 3 and Figure 5 As shown, the key structural parameters of the aircraft diffuser component 402 in this embodiment are: the minimum widths W0 of the radial blade flow channel and the axial blade flow channel are 14 mm and 5 mm, respectively; the minimum widths W2 of the radial blade and the axial blade are 0.5 mm and 0.7 mm, respectively; the diameter D1 of the maximum profile of the aircraft diffuser component 302 is 430 mm; and the maximum height H is 55 mm.

[0025] S102: Based on the structural characteristics of the aerospace diffuser component 402, determine the appropriate range of particle medium 3 size d and the inner cavity size D0 of the main vibrating body container 2; and the setting of these two ranges should ensure that the particle medium 3 has high processing efficiency for the aerospace diffuser component 402, while also ensuring good flowability of the particle medium 3 within the flow channel. The specific design is as follows: ① To prevent particulate medium 3 from clogging the flow channel of the aerospace diffuser component 402, the equivalent diameter d of particulate medium 3 should satisfy the following inequality: ; In the formula, W0 is the minimum width of the radial or axial blade flow channel of the aircraft diffuser part 402; α is the geometric compatibility coefficient, which is generally taken as 0.2 to 0.3.

[0026] In this embodiment, considering that the selected particle medium 3 is shaped as oblique triangular silicon carbide, the geometric compatibility coefficient α is selected as 0.3. Based on this upper limit of calculation, and considering that in order to ensure that a single abrasive grain has sufficient cutting force, the abrasive with an equivalent diameter d of 4 mm is finally preferred for the particle medium 3.

[0027] ② To ensure good fluidity of the particulate medium 3 within the inner cavity of the main vibrating body container 2, the inner cavity diameter D0 of the main vibrating body container 2 should satisfy the following inequality: ; In the formula, D1 is the maximum diameter of the profile of the aerospace diffuser part 402; δ is the minimum spacing to ensure the fluidity of the particulate medium 3, and Through calculation, a cylindrical container with an inner cavity diameter D0 of 520 mm was selected as the main vibrating body container 2.

[0028] Optionally, such as Figure 2-8 As shown, radial contouring protection component 401 and axial contouring protection component 403 are designed based on the structural characteristics of the aircraft diffuser component 402. These components, together with the diffuser component 402, form a combined subjective and objective device wall structure 4 to regulate the flow field of the particulate medium 3 and prevent over-throwing in areas such as blade tips. Simultaneously, the radial contouring blade 4013, limiting plate 4014, and axial contouring blade 4033 are used to enhance the device wall effect and improve the processing effect of the particulate medium 3 on the flow channel. The specific structural settings of the radial contouring protection component 401 and axial contouring protection component 403 are as follows: The aircraft diffuser component 402 is annularly shaped, with several radially distributed blades on its end face and several axially distributed blades on its outer circumferential surface. The radially contoured protective component 401 includes a vertically intersecting upper mounting plate 4011 and a mounting post 4012. The mounting post 4012 is used to vertically pass through the central shaft hole of the aircraft diffuser component 402 to vertically mount the aircraft diffuser component 402 along the axial direction. The upper mounting plate 4011 is horizontally spaced above the end face of the aircraft diffuser component 402, and the lower end of the upper mounting plate 4011 is concavely machined to form a stepped annular surface. Several radially contoured blades 4013 are provided on the circumference of the stepped annular surface, corresponding to several radially contoured blades. Each radially contoured blade 4013 has a vertically positioned limiting piece 4014 extending to the outer side of the corresponding radial blade tip below at its cantilever end.

[0029] Furthermore, the axial contouring protective component 403 includes a lower mounting plate 4031 and a connecting plate 4032 arranged axially in sequence; after the mounting column 4012 vertically passes through the central shaft hole of the aircraft diffuser part 402, its bottom end presses the flange of the cover end of the aircraft diffuser part 402 onto the lower mounting plate 4031. The connecting plate 4032 is used to support and fix it on the tooling fixture 5 below. The axial contouring protective component 403, the aircraft diffuser part 402, and the radial contouring protective component 401 are detachably fixed by bolts passing through the connecting plate 4032, the flange of the cover end of the aircraft diffuser part 402, and the mounting column 4012. The lower mounting plate 4031 is provided with a number of axial contouring blades 4033 arranged in a contouring manner corresponding to a number of axial blades in the circumferential direction. The number of axial contouring blades 4033 are connected to the lower mounting plate 4031 to form an upward-facing bottom cover. The bottom cover is used to be radially spaced and fastened to the outside of the cover end of the aircraft diffuser part 402.

[0030] Preferably, the widths of the radially contoured blade 4013 and the axially contoured blade 4033 need to be calculated based on the required coverage factor and satisfy the following inequality, thereby avoiding the over-throwing problem caused by the strong impact of the particulate medium 3 on the blade tip region during vibration. The specific inequality is as follows: ; In the formula, W1 is the width of the radially contoured blade 4013 and the axially contoured blade 4033; W2 is the actual width of the radial and axial blades of the aircraft diffuser part 402; δ1 is the single-sided assembly positioning error between the radially contoured blade 4013 or the axially contoured blade 4033 and the aircraft diffuser part 402, with a value range of 0.5 to 0.8 mm, preferably 0.5 mm; A1 is the equivalent displacement amplitude of the oscillation around the Z-axis applied by the excitation polishing device 1 to the main vibrating body container 2, with a value range of 2 to 4 mm, preferably 3 mm; λ is the vibration randomness compensation coefficient, with a value range of 0.7 to 0.9, preferably 0.8.

[0031] In this embodiment, the actual widths W2 of the radial and axial blades of the aircraft diffuser component 402 are 0.5 mm and 0.7 mm, respectively, with the larger value of 0.7 mm used for calculation; δ1 is 0.5 mm, A1 is 3 mm, and λ is 0.8. Calculations show that the width W1 of the radial contouring protection component 401 and the axial contouring protection component 403 is not less than 4.1 mm. Therefore, in this embodiment, W1 is set to 4.1 mm to achieve coverage protection for the blade tip area.

[0032] Preferably, such as Figure 8As shown, the installation and clearance design of the radial contour blade 4013 and the axial contour blade 4033 must meet the incident angle condition, specifically including the vertical clearance L and the lateral overhang S. The vertical clearance L between the radial contour blade 4013 and the corresponding radial blade, and the vertical clearance L between the axial blade and the upper surface of the lower mounting plate 4031, must both satisfy the following inequality: ; In the formula, β is the damping safety factor, which ranges from 0.6 to 0.8, preferably 0.7; d is the equivalent diameter of the particulate medium 3. In this embodiment, β is 0.7 and d is 4 mm. The calculated vertical gap L should not be greater than 2.8 mm. Therefore, in this embodiment, the vertical gap L is 2.5 mm to ensure that the particulate medium 3 cannot directly enter the gap or cause jamming. At the same time, there is a certain downward pressing installation gap between the radial profile blade 4013 and the corresponding radial blade, and between the axial blade and the upper surface of the lower mounting plate 4031, to avoid the radial profile blade 4013 pressing against the corresponding radial blade and the axial blade pressing against the lower mounting plate 4031 after installation, which would cause installation interference and affect the processing effect of the blade flow channel and profile.

[0033] Furthermore, the lateral overhang S between the radial blade tip and the corresponding limiting piece 4014, and the lateral overhang S between the axial blade tip and the corresponding axial contour blade 4033, must satisfy the following inequality with respect to the vertical clearance L: ; In the formula, θ is the maximum incident angle of the particulate medium 3 on the blade tip region, and its value is no greater than 20°. Based on the determined vertical gap L, the lateral overhang S in this embodiment is set to 7 mm. At this time, the maximum incident angle of the particulate medium 3 entering the gap is limited to within 20°, so that the normal impact of the particulate medium 3 on the blade tip is less and the tangential sliding friction is more, effectively preventing rounding and excessive wear of the blade tip.

[0034] Optionally, such as Figure 7 As shown, the tooling fixture 5 is used to fix the wall structure 4 of the main and objective components to the vibratory polishing device 1, and a certain amount of particulate medium 3 and liquid medium are added into the main vibrator container 2. In this embodiment, the tooling fixture 5 is a long strip plate structure with a length d1=350 mm and a height h1=25 mm, and multiple hexagon countersunk screw mounting holes are provided along the length direction to achieve a detachable fixed connection of the wall structure 4 of the main and objective components.

[0035] Preferably, the total height of the particulate medium 3 filling the inner cavity of the main vibrating body container 2 is the distance between the highest point of the main and objective combined structure wall 4 and the total height of the particulate medium 3 filling the inner cavity of the main vibrating body container 2. The liquid medium should be a mixture of grinding fluid and water with a pH value greater than 7, which has lubricating, cleaning, softening, and anti-corrosion functions.

[0036] Furthermore, the installation height H0 of the subjective-objective combiner wall structure 4 should satisfy the following inequality: ; In the formula, H0 is the vertical installation height of the geometric center of the main and objective combined wall structure 4 relative to the bottom of the main vibrating body container 2; H1 is the total filling height of the particulate medium 3 in a static state; γ1 and γ2 are the flow field energy level distribution coefficients, wherein the value of γ1 is in the range of 0.3 to 0.5, preferably 0.4; the value of γ2 is in the range of 0.6 to 0.8, preferably 0.7, and γ1 < γ2.

[0037] In this embodiment, the total filling height H1 of the particulate medium 3 in a static state is 260 mm, and the installation height H0 of the subjective and objective combiner wall structure 4 is 165 mm. Calculations show that 0.4H1 = 104 mm and 0.7H1 = 182 mm, satisfying the installation height requirement of 0.4H1 ≤ H0 ≤ 0.7H1. Figure 6 As shown. The total filling height of the particulate medium 3 in the main vibrator container 2 is 67.5 mm away from the highest point of the main and objective combined structure wall 4. The liquid medium is a mixture of grinding fluid and water with a pH value in the range of 8.2 ± 0.2, which has the functions of lubrication, cleaning, softening and corrosion prevention.

[0038] Optionally, in step S40, the installation angle φ of the two main vibrating motors 201 on the main vibrating body container 2 is set to 0°~30°, preferably 15°; the frequency f1 of the main vibrating motor 201 is set to 0~25 Hz, preferably 25 Hz; and the frequency f2 of the two vibration isolation motors 601 on the vibration isolation body 6 is set to 0~50 Hz, preferably 50 Hz.

[0039] In this embodiment, the installation angle φ of the main vibrating motor 201 is 15°, and the frequency f1 is 25 Hz; the frequency f2 of the isolating motor 601 is 50 Hz. Under the action of the excitation polishing device 1, the particulate medium 3 couples to form a multidimensional composite vibration flow field and exhibits a high-energy fluidization state, which collides, rolls, and rubs against the flow channel and blade profile of the aerospace diffuser part 402, thereby reducing surface roughness and improving surface morphology.

[0040] Optionally, in step S50, the processing time is set to 120 minutes. After processing, the aerospace diffuser part 402 is removed, ultrasonically cleaned, and the processing effect is inspected. In this embodiment, a comparison of the surface morphology and surface roughness of a certain high-temperature alloy diffuser part 402 before and after processing is shown below. Figures 9 to 12As shown in the figure, before processing, different regions exhibited obvious grinding textures with significant differences in peak-to-trough heights, high surface roughness values, and anisotropy. The initial surface roughness Ra values ​​of the three regions were 1.099 ± 0.006 μm, 0.974 ± 0.012 μm, and 1.178 ± 0.110 μm, respectively. After vibratory polishing, the grinding textures on the surfaces of different regions were effectively removed, the peak-to-trough height differences decreased, and the surface morphology was effectively improved. Simultaneously, the surface roughness Ra values ​​of the three regions decreased to 0.519 ± 0.006 μm, 0.585 ± 0.005 μm, and 0.744 ± 0.014 μm, respectively, with reduction rates of 52.8%, 39.9%, and 36.8%. The results show that the proposed excitation polishing method for finishing aircraft diffusers can effectively reduce the grinding texture on the surface of the blades and flow channels of aircraft diffuser part 402, reduce surface roughness, and improve the surface quality of complex surfaces, while controlling the risk of over-polishing and surface damage.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A vibratory polishing method for finishing aircraft diffusers, characterized in that, Includes the following steps: S10: Analyze the structural features and processing requirements of the aircraft diffuser part (402) to determine the inner cavity size D0 of the main vibrating body container (2) used for vibratory polishing of the part and the size d of the particulate medium (3) on the vibratory polishing device (1); S20: Based on the structural characteristics of the aircraft diffuser component (402), design radial contour protection component (401) and axial contour protection component (403) to assemble with the diffuser component to form a subjective and objective combined wall structure (4) to regulate the flow field of particulate medium (3); S30: The objective and subjective combination wall structure (4) is installed and fixed in the inner cavity of the main vibrating body container (2) using tooling fixture (5), and a certain amount of particulate medium (3) and liquid medium are added to the inner cavity; S40: Set the installation angle φ and frequency f1 of the two main vibrating motors (201) on both sides of the main vibrating container (2), and set the frequency f2 of the two vibration isolation motors (601) on the vibration isolation body (6) below the main vibrating container (2), so that the particulate medium (3) is coupled to form a multidimensional composite vibration flow field under the active excitation of the vibration polishing device (1), and then the flow channel and blade profile of the aircraft diffuser part (402) are processed. S50: After processing, the aircraft diffuser part (402) is removed, ultrasonically cleaned, and the processing effect is tested.

2. The vibratory polishing method for finishing aircraft diffusers according to claim 1, characterized in that, In step S10, to prevent the particulate medium (3) from clogging the flow channel of the aerospace diffuser component (402), the equivalent diameter d of the particulate medium (3) should satisfy the following inequality: ； In the formula, W0 is the minimum width of the radial or axial blade flow channel of the aircraft diffuser part (402); α is the geometric compatibility coefficient, which is generally taken as 0.2 to 0.

3.

3. The vibratory polishing method for finishing aircraft diffusers according to claim 1, characterized in that, In step S10, to ensure good fluidity of the particulate medium (3) within the inner cavity of the main vibrating body container (2), the inner cavity diameter D0 of the main vibrating body container (2) should satisfy the following inequality: ； In the formula, D1 is the maximum diameter of the profile of the aerospace diffuser part (402); δ is the minimum spacing to ensure the fluidity of the particulate medium (3), and .

4. The vibratory polishing method for finishing aircraft diffusers according to claim 1, characterized in that, The aircraft diffuser part (402) is in the shape of an annular cover, with a number of radial blades evenly distributed in the circumferential direction on the end face of the cover, and a number of axial blades evenly distributed in the circumferential direction on the outer circumferential surface of the cover opening. The radial profiled protective element (401) includes a vertically intersecting upper mounting plate (4011) and a mounting post (4012), the mounting post (4012) being used to vertically pass through the central shaft hole of the aircraft diffuser part (402) to vertically mount the aircraft diffuser part (402) in the axial direction. The upper mounting plate (4011) is horizontally spaced above the cover end of the aircraft diffuser part (402), and the lower end of the upper mounting plate (4011) is recessed to form a stepped annular surface. The stepped annular surface is provided with a number of radially contoured blades (4013) corresponding to the radial blades in the circumferential direction. Each radially contoured blade (4013) has a vertically arranged limiting piece (4014) at its cantilever end that extends to the outer side of the corresponding radial blade tip below.

5. The vibratory polishing method for finishing aircraft diffusers according to claim 4, characterized in that, The axial contour protection component (403) includes a lower mounting plate (4031) and a connecting plate (4032) arranged sequentially in the axial direction. After the mounting column (4012) vertically passes through the central shaft hole of the aircraft diffuser part (402), its bottom end presses the flange of the cover end of the aircraft diffuser part (402) onto the lower mounting plate (4031). The connecting plate (4032) is used to support and fix it on the tooling fixture (5) below. The axial contouring protective part (403), the aircraft diffuser part (402) and the radial contouring protective part (401) are detachably fixed by the bolts passing through the connecting plate (4032), the flange of the cover end of the aircraft diffuser part (402) and the mounting column (4012). The lower mounting plate (4031) is provided with a number of axially contoured blades (4033) in the circumferential direction, which are corresponding to the axial blades. The number of axially contoured blades (4033) are connected to the lower mounting plate (4031) to form an upward-facing bottom cover. The bottom cover is used to be radially and spaced to be fastened to the outside of the cover end of the aircraft diffuser part (402).

6. The vibratory polishing method for finishing aircraft diffusers according to claim 5, characterized in that, The widths of both the radially contoured blade (4013) and the axially contoured blade (4033) must satisfy the following inequality: ； In the formula, W1 is the width of the radially contoured blade (4013) or the axially contoured blade (4033); W2 is the actual width of the radial and axial blades of the aircraft diffuser part (402); δ1 is the single-sided assembly positioning error between the radially contoured blade (4013) or the axially contoured blade (4033) and the aircraft diffuser part (402), with a value range of 0.5 to 0.8 mm; A1 is the equivalent displacement amplitude of the swing around the Z-axis applied by the excitation polishing device (1) to the main vibrating container (2), with a value range of 2 to 4 mm; λ is the vibration randomness compensation coefficient, with a value range of 0.7 to 0.

9.

7. The vibratory polishing method for finishing aircraft diffusers according to claim 6, characterized in that, The installation and clearance design of the radial contour blade (4013) and the axial contour blade (4033) must meet the incident angle conditions, specifically including the vertical clearance L and the lateral overhang S. Among them, the vertical clearance L between the radial contour blade (4013) and the corresponding radial blade, and the vertical clearance L between the axial blade and the upper surface of the lower mounting plate (4031) must both satisfy the following inequality: ； In the formula, β is the damping safety factor, which ranges from 0.6 to 0.8; d is the equivalent diameter of the particulate medium (3); In addition, the lateral overhang S between the radial blade tip and the corresponding limiting plate (4014), and the lateral overhang S between the axial blade tip and the corresponding axial contour blade (4033), must satisfy the following inequality with respect to the vertical clearance L: ； In the formula, θ is the maximum incident angle of the particulate medium (3) on the tip region of the blade, and its value is no greater than 20°.

8. The vibratory polishing method for finishing aircraft diffusers according to claim 1, characterized in that, In step S30, the tooling fixture (5) is a long strip plate structure, and multiple internal hexagon countersunk screw mounting holes are provided along the length direction to realize the detachable fixed connection of the main and objective assemblies wall structure (4). In step S30, the total filling height of the particulate medium (3) in the inner cavity of the main vibrating body container (2) is the distance between the highest point of the main and objective combined structure wall (4). ; In step S30, the liquid medium is selected as a mixture of grinding slurry with a pH value greater than 7 and water.

9. The vibratory polishing method for finishing aircraft diffusers according to claim 1, characterized in that, The installation height H0 of the subjective and objective combiner wall structure (4) should satisfy the following inequality: ； In the formula, H0 is the vertical installation height of the geometric center of the main and objective combined wall structure (4) relative to the bottom of the main vibrating body container (2); H1 is the total filling height of the particulate medium (3) in a static state; γ1 and γ2 are the flow field energy level distribution coefficients, where the value of γ1 is 0.3 to 0.5; the value of γ2 is 0.6 to 0.8, and γ1 < γ2.

10. The vibratory polishing method for finishing aircraft diffusers according to claim 1, characterized in that, In step S40, the installation angle φ of the two main vibrating motors (201) on the main vibrating body container (2) is set to 0°~30° and the frequency f1 is set to 0~25 Hz; the frequency f2 of the two vibration isolation motors (601) on the vibration isolation body (6) is set to 0~50 Hz.

Images