Aero-engine negative pressure cycle backwashing process, system and clamp

Abstract

The present application relates to the technical field of aero-engine, more particularly to an aero-engine negative pressure cycle backwashing process, system and clamp, comprising the following steps: S1, clamping and fixing; S2, first liquid feeding; S3, spraying and circulating; S4, first liquid returning; S5, second liquid feeding; S6, backwashing and circulating; S7, second liquid returning; S8, detecting and unloading. The backwashing system comprises a vacuum cleaning tank, a liquid storage and return tank, a circulating filter pump, a vacuum pump, an online particle size detection device and a controller. The backwashing clamp comprises a bottom plate, a connecting plate, a pressing assembly and a first pipe joint, the connecting plate is arranged above the bottom plate, the pressing assembly is fixedly connected with the connecting plate, the first pipe joint is arranged on the pressing assembly, the first pipe joint comprises an integrated liquid feeding box and a liquid outlet, the liquid outlet is communicated with a backwashing pipe opening, and the integrated liquid feeding box is communicated with a plurality of oil path interfaces on the top surface of the engine case. The present application effectively peels off the deposited particles attached to the complex oil path, and realizes omnibearing and dead angle-free cleaning.

Description

Technical Field

[0001] This invention relates to the technical field of aero-engines, and more specifically, to an aero-engine negative pressure circulation backwashing process, system, and fixture. Background Technology

[0002] In the manufacturing and use of aero-engines, the presence of internal foreign matter is a significant factor affecting engine operational safety and reliability. Foreign matter mainly includes tiny particles such as iron filings, sand, and dust left over from the machining process, which are hidden within the complex oil passages, precision cavities, and intersecting hole structures of components. With the increasing frequency of engine use, problems caused by foreign matter, such as bearing slippage, wear, nozzle clogging, and lubrication system failure, are becoming increasingly prominent, seriously threatening flight safety. Therefore, improving the cleanliness control level of components has become a critical aspect of aero-engine production.

[0003] The commonly used cleaning method is forward pressure flushing, which uses high-flash-point organic solvents or aviation kerosene as the cleaning medium. Under certain pressure, the oil passages and internal cavities of the casing are forward-sprayed and flushed, and the cleanliness is determined by observation through a filter and particle size detection. However, when using forward pressure flushing to clean complex rotating casings, the complex internal structure of the casing, including precision cavities, strip-shaped annular cavities, and multiple vertically connected intersecting oil passages, can lead to poor flow of the cleaning medium in some areas. This results in the inability to effectively remove excess material, which accumulates over time and forms a stubborn deposit. In actual use, engine vibration may loosen these deposits, allowing them to enter the fuel or lubricating oil system, causing secondary contamination and system malfunctions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies that cannot thoroughly clean the excess deposits in the complex oil passages inside aero engines, and to provide a negative pressure circulation backwashing process, system and fixture for aero engines, which effectively removes deposited particles attached to the corners, dead corners and semi-enclosed cavities of the oil passages, and achieves all-round cleaning of the complex internal structure without dead corners.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A negative pressure circulation backwashing process for aircraft engines is provided, comprising the following steps: S1. Clamping and fixing: Fix the casing to be rinsed onto the vibrating worktable in the vacuum cleaning tank using the backwashing clamp, and seal and connect each oil circuit interface of the casing to the backwashing pipe port, so that the spray pipe port is aligned with the casing. S2, First liquid injection: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the liquid storage return tank is injected into the vacuum cleaning tank through the backwash port and the spray port until the casing is completely submerged, so that the cleaning medium fills the inner cavity of the casing and the cross oil passages. S3, Spraying Circulation: Start the ultrasonic generator and the vibrating worktable, extract the cleaning medium from the vacuum cleaning tank through the circulating filter pump, and spray it into the vacuum cleaning tank through the spray nozzle to form a spraying circulation. S4, First return of liquid: The gas in the liquid storage return tank is drawn into the gas-liquid separation tank by a vacuum pump, and a vacuum negative pressure is formed in the liquid storage return tank. The cleaning medium in the vacuum cleaning tank is drawn into the liquid storage return tank by a circulating filter pump. S5. Secondary liquid injection: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the liquid storage return tank is injected into the vacuum cleaning tank through the backwash port and the spray port until the casing is completely submerged, so that the cleaning medium fills the inner cavity of the casing and the cross oil passages. S6. Backwashing circulation: The cleaning medium is drawn out of the vacuum cleaning tank from the backwashing port by the circulating filter pump and sprayed into the vacuum cleaning tank from the spray port, so that the cleaning medium forms a continuous reverse flow in the oil circuit of the casing from the original oil outlet to the oil inlet. S7, Secondary Liquid Return: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the casing oil circuit is drawn into the liquid storage return tank from the backwash port. The cleaning medium in the vacuum cleaning tank is drawn into the liquid storage return tank by the circulating filter pump. S8. Unloading Detection: When the circulating filter pump draws the cleaning medium in the vacuum cleaning tank, the particle concentration in the cleaning medium is monitored in real time by an online particle size detection device, and the detection signal is fed back to the controller. When the particle concentration detection result does not meet the preset cleanliness standard, steps S2 to S7 are repeated. When the particle concentration detection result meets the preset cleanliness standard, the controller automatically shuts down the vacuum pump, circulating filter pump, ultrasonic generator, and vibrating worktable, and removes the casing from the backwashing fixture.

[0006] The negative pressure circulation backwashing process for aero-engines of this invention first uses a backwashing clamp to fix the casing to be washed onto a vibrating worktable inside a vacuum cleaning tank, and seals the oil circuit interfaces of the casing with the backwashing pipe ports. Then, a vacuum negative pressure is created in the vacuum cleaning tank using a vacuum pump, and the cleaning medium is injected into the tank through the backwashing and spray pipe ports until the casing is completely submerged. Next, an ultrasonic generator and the vibrating worktable are activated, and the cleaning medium is extracted by a circulating filter pump and sprayed into the tank through the spray pipe ports, forming a spray cycle. After one return cycle, the vacuum negative pressure process is repeated. The cleaning medium is first pumped out of the backwash port and then sprayed into the spray port through a circulating filter pump, creating a continuous reverse flow from the original outlet to the inlet in the casing oil circuit, thus achieving backwashing circulation. Subsequently, vacuum negative pressure draws the cleaning medium from the casing oil circuit into the liquid return tank. Throughout the rinsing process, an online particle size detection device monitors the particle concentration in the cleaning medium in real time. If the detection result does not meet the preset cleanliness standard, the liquid injection, spraying, backwashing, and return steps are automatically repeated until the standard is met. Afterward, the controller automatically shuts down all components and unloads the material. This process, through vacuum negative pressure-driven reverse continuous flow, ultrasonic vibration coupled peeling, and online detection closed-loop control, effectively removes deposited particles from complex oil circuit corners and dead angles, achieving thorough cleaning and significantly improving cleanliness compliance rate and batch consistency. Simultaneously, it achieves fully automated control, greatly improving cleaning efficiency.

[0007] Preferably, the ultrasonic generator operates at a frequency of 25-30 kHz, and the vibration table operates at a frequency of 5-15 Hz. Preferably controlling the ultrasonic generator's operating frequency within the 25-30 kHz range allows for the generation of a strong cavitation effect in the cleaning medium, forming numerous microbubbles that release instantaneous high-temperature, high-pressure shock waves upon rupture. This effectively removes excess particulate matter adhering to the inner cavity of the casing and the walls of the oil passages. Simultaneously, the 5-15 Hz mechanical vibration of the vibration table works synergistically to create a coupled turbulent flow field within the complex oil passages. This allows the cleaning medium to penetrate deep into the corners and dead zones of variable-diameter, curved, and intersecting oil passages, thoroughly loosening and suspending deposited particles that traditional forward flushing cannot reach within the medium, significantly improving the thoroughness of cleaning the complex casings of aero-engines.

[0008] Preferably, the circulating filter pump performs multi-stage gradient filtration on the cleaning medium flowing through it, and the minimum pore size in the multi-stage gradient filtration is 4~6μm. By using a circulating filter pump to perform multi-stage gradient filtration on the flowing cleaning medium, and preferably controlling the minimum filtration pore size to be 4~6μm, by setting the filtration stages from coarse to fine in the circulation path, it can not only efficiently intercept large particles and excess matter to prevent filter screen clogging, but also accurately capture tiny particles to meet the cleanliness requirements of aero-engines; the filtered clean medium is re-injected into the vacuum cleaning tank to participate in the circulation rinsing, avoiding secondary adhesion of particles inside the casing.

[0009] The present invention also provides a backwashing system, comprising: A vacuum cleaning tank is used to contain the cleaning medium and immerse the casing. It is equipped with an ultrasonic generator and a vibrating worktable inside. A liquid reflux tank is sealed and connected to the vacuum cleaning tank, and is used to store and recycle the cleaning medium; A circulating filter pump is connected between the vacuum cleaning tank and the liquid return tank to drive the cleaning medium to circulate. A vacuum pump is connected to a vacuum cleaning tank, a liquid storage reflux tank, and a gas-liquid separation tank to create a negative pressure environment. An online particle size detection device is installed on the connecting pipeline between the circulating filter pump and the vacuum cleaning tank to monitor the particle concentration of the cleaning medium in real time. The controller is connected to the online particle size detection device, vacuum pump, circulating filter pump, vibrating worktable, and ultrasonic generator to automatically control the rinsing process based on the particle size detection results.

[0010] The backwashing system of this invention includes an ultrasonic generator and a vibrating worktable installed in a vacuum cleaning tank, with the casing to be cleaned immersed in the cleaning medium. A vacuum pump is connected to the vacuum cleaning tank, a liquid return tank, and a gas-liquid separation tank to create a negative pressure environment within the system, driving the cleaning medium to flow continuously in the casing's oil circuit from the original oil outlet to the oil inlet. A circulating filter pump is connected between the vacuum cleaning tank and the liquid return tank, driving the cleaning medium to circulate and perform multi-stage gradient filtration. An online particle size detection device monitors the particle concentration of the cleaning medium in the circulating pipeline in real time and feeds the detection signal back to the controller. The controller automatically controls the start-up, shutdown, and process switching of the vacuum pump, circulating filter pump, vibrating worktable, and ultrasonic generator based on the particle size detection results. When the detection results do not meet the preset cleanliness standard, the controller controls the repeated execution of the liquid inlet, spraying, backwashing, and liquid return steps until the standard is met, at which point the system is automatically shut down. This system achieves efficient removal of particles from complex oil passage dead zones and fully automated control through the synergistic effects of vacuum negative pressure driven reverse continuous flow, ultrasonic vibration coupled stripping, multi-stage gradient filtration, and online detection closed-loop control. It significantly improves the consistency and reliability of cleaning quality and meets the high cleanliness requirements of aero-engines.

[0011] Furthermore, the vacuum cleaning tank is equipped with spray nozzles on both sides for spray cleaning of the casing surface; the bottom of the vacuum cleaning tank is equipped with a backwash nozzle for sealing connection with each oil passage interface of the casing to achieve reverse suction cleaning. The spray nozzles are used for high-pressure spray cleaning of the casing surface, effectively removing loose particles attached to the outer surface, while the backwash nozzles are sealed to each oil passage interface of the casing to achieve reverse suction cleaning; the two work together to ensure that the inner and outer surfaces of the casing and the complex oil passages are simultaneously flushed by the cleaning medium. Spray cleaning ensures the cleanliness of the outer surface, while backwashing circulation penetrates deep into the oil passages to remove dead corner deposited particles. The combination of internal and external cleaning achieves all-round, dead-angle-free cleaning of the casing, significantly improving the overall cleanliness.

[0012] Furthermore, the vibrating worktable is slidably connected to the vacuum cleaning tank. A universal base for fixing the casing is provided on the vibrating worktable, and a chip removal groove is formed on the universal base. A vibration source is installed below the vibrating worktable. Sliding the vibrating worktable to the vacuum cleaning tank facilitates quick pushing and pulling of the casing by the operator, improving work efficiency. The universal base with the chip removal groove is provided on the worktable, the casing is clamped onto the base, and the vibration source is installed below the worktable. When the vibrating worktable is started, mechanical vibration is transmitted to the casing through the base, causing particles adhering to the inner wall to loosen and fall off. The detached particles fall directly into the chip removal groove and are promptly carried away by the cleaning medium, preventing secondary deposition or re-adsorption of particles at the bottom of the casing.

[0013] Furthermore, the circulating filter pump is internally equipped with multiple sets of filter screens with progressively smaller pore sizes, and these filter screens are detachably connected to the circulating filter pump. The arrangement of these multiple filter screens with decreasing pore sizes inside the circulating filter pump forms a gradient filtration structure. The large-pore screens first intercept large particles to protect the downstream filter screens, while the medium and small-pore screens gradually capture tiny particles, thus meeting the high cleanliness requirements of aero-engines. The detachable connection between the filter screens and the circulating filter pump facilitates quick disassembly, cleaning, or replacement, reducing maintenance difficulty and operating costs, and ensuring the long-term stable operation of the filtration system.

[0014] The present invention also provides a backwashing clamp, including a base plate, a connecting plate, a clamping assembly, and a first pipe connector. The base plate is fixed to the vibrating worktable. The connecting plate is disposed above the base plate and is used to support the casing. The clamping assembly is fixedly connected to the connecting plate and is used to clamp and fix the casing to the connecting plate. The first pipe connector is disposed on the clamping assembly and includes an integrated liquid inlet box and a liquid outlet. The liquid outlet communicates with the backwashing pipe port, and the integrated liquid inlet box communicates with multiple oil passage interfaces on the top surface of the casing.

[0015] The backwashing fixture of this invention, after fixing the base plate to the vibrating worktable, mounts the casing on the connecting plate, and then fixes the casing position by a clamping assembly, connecting the first pipe connector to the oil circuit interface of the casing. When the negative pressure circulation is started, the cleaning medium flows out from multiple oil circuit interfaces on the top surface of the casing, collects through the integrated liquid inlet box to the outlet of the first pipe connector, and then enters the backwashing port, realizing multi-oil circuit reverse flushing. This fixture, through the integrated liquid inlet box design, connects multiple oil circuit interfaces on the top surface of the casing simultaneously with a single pipe connector, achieving multi-oil circuit single-interface integration. It can simultaneously connect multiple oil circuit interfaces on the end face of the casing, significantly reducing the number of pipe connectors and the complexity of pipeline connections, providing a stable clamping and installation effect for the negative pressure circulation backwashing process.

[0016] Furthermore, the clamping assembly includes a support rod and a top pressure plate. The support rod is connected to the connecting plate, and the top pressure plate is detachably connected to the support rod. The first pipe connector is disposed on the top pressure plate. During installation, the support rod passes through the inside of the casing, and then the top pressure plate is installed on top of the support rod, thereby clamping the casing. When the top pressure plate clamps the top surface of the casing, the first pipe connector automatically aligns and connects with multiple oil passage interfaces on the top surface of the casing, eliminating the need for separate pipe insertion operations, simplifying the clamping process, and shortening the installation time. At the same time, the detachable connection between the top pressure plate and the support rod facilitates quick replacement of the appropriate top pressure plate according to different casing models, improving the versatility of the fixture.

[0017] Furthermore, it also includes a side pressure plate, a second pipe connector, and a third pipe connector. The side pressure plate is detachably installed on the side wall of the casing. The second pipe connector is disposed on the side pressure plate and connects the side oil passage of the casing to the backwash port. The third pipe connector is disposed on the connecting plate and connects the bottom oil passage of the casing to the backwash port. This multi-directional pipe connector layout enables the simultaneous completion of backwash connections for all oil passages on the top, bottom, and side walls of the casing in a single clamping configuration, eliminating the need for multiple clamping operations for oil passages in different orientations, as is required with traditional clamps.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. Thoroughly removes particles from complex oil passage dead corners. Through negative pressure reverse circulation coupled with ultrasonic vibration, the cleaning medium forms a continuous reverse flow from the original oil outlet to the oil inlet in the changing diameter, bending and crossing oil passages of the casing. Combined with the ultrasonic cavitation effect and the turbulent field generated by low frequency mechanical vibration, it effectively peels off the deposited particles attached to the corners, dead corners and semi-enclosed cavities of the oil passage, realizing all-round cleaning of the complex structure without dead corners. 2. Achieve high-cleanliness closed-loop control, improve cleaning efficiency and consistency. The online particle size detection device monitors the particle concentration in the cleaning medium in real time and feeds the detection signal back to the controller. The controller automatically determines whether the cleanliness meets the standard and controls the start and stop of the process. The multi-stage gradient filtration system ensures that the cleaning medium remains clean during the circulation process and avoids secondary particle adhesion. 3. Multi-oil-path reverse flushing can be completed in one clamping. The first pipe joint adopts a multi-oil-path single-interface integrated structure, which can simultaneously connect multiple oil-path interfaces on the end face of the casing, and cooperate with the second and third pipe joints. Flushing can be completed in one clamping, simplifying the operation process and shortening the flushing time. Attached Figure Description

[0019] Figure 1 A flowchart illustrating the negative pressure circulation backwashing process for aero-engines; Figure 2 This is a schematic diagram of the backwashing system. Figure 3 This is a schematic diagram illustrating the principle of a single liquid inlet. Figure 4 This is a schematic diagram illustrating the principle of spray circulation; Figure 5 This is a schematic diagram illustrating the principle of a single liquid return cycle. Figure 6 This is a schematic diagram illustrating the principle of the backwashing cycle; Figure 7 This is a schematic diagram illustrating the principle of secondary liquid return. Figure 8 A schematic diagram illustrating the principle of material unloading detection; Figure 9 Front view of the backwash fixture; Figure 10 Top view of the backflushing fixture; Figure 11 This is a schematic diagram showing the backwashing fixture in use. Figure 12 Top view of the backflushing clamp in use; Figure 13 Main view showing the backwashing fixture in use.

[0020] In the attached diagram: 100, casing; 200, base plate; 300, connecting plate; 400, clamping assembly; 410, support rod; 420, top pressure plate; 500, first pipe connector; 510, integrated liquid inlet box; 520, liquid outlet; 600, side pressure plate; 610, second pipe connector; 700, third pipe connector. Detailed Implementation

[0021] 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.

[0022] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the system or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0023] Example 1 This embodiment is the first embodiment of the negative pressure circulation backwashing process for aircraft engines, including the following steps: S1. Clamping and fixing: Fix the casing 100 to be rinsed to the vibrating worktable in the vacuum cleaning tank using the backwashing clamp, and seal and connect each oil circuit interface of the casing 100 to the backwashing pipe port, so that the spray pipe port is aligned with the casing 100. S2, First liquid injection: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the storage return tank is injected into the vacuum cleaning tank through the backwash pipe and the spray pipe until the casing 100 is completely submerged, so that the cleaning medium fills the inner cavity of the casing 100 and the cross oil passages. S3, Spray Circulation: Start the ultrasonic generator and vibrating worktable, and use the circulating filter pump to extract the cleaning medium from the vacuum cleaning tank and spray it into the vacuum cleaning tank through the spray nozzle to form a spray circulation. S4, First-time liquid return: The gas in the liquid return tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the liquid return tank. The cleaning medium in the vacuum cleaning tank is drawn into the liquid return tank by the circulating filter pump. S5, Secondary liquid inlet: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the storage return tank is injected into the vacuum cleaning tank through the backwash pipe and the spray pipe until the casing 100 is completely submerged, so that the cleaning medium fills the inner cavity of the casing 100 and the cross oil passages. S6. Backwashing circulation: The cleaning medium is drawn out of the vacuum cleaning tank from the backwashing pipe through the circulating filter pump and sprayed into the vacuum cleaning tank from the spray pipe, so that the cleaning medium forms a continuous reverse flow in the oil circuit of the casing 100 from the original oil outlet to the oil inlet. S7, Secondary Liquid Return: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the oil circuit of the casing 100 is drawn into the liquid storage return tank from the backwash pipe. The cleaning medium in the vacuum cleaning tank is drawn into the liquid storage return tank by the circulating filter pump. S8. Unloading Detection: When the circulating filter pump draws the cleaning medium in the vacuum cleaning tank, the particle concentration in the cleaning medium is monitored in real time by an online particle size detection device, and the detection signal is fed back to the controller. When the particle concentration detection result does not meet the preset cleanliness standard, steps S2 to S7 are repeated. When the particle concentration detection result meets the preset cleanliness standard, the controller automatically shuts down the vacuum pump, circulating filter pump, ultrasonic generator and vibrating worktable, and removes the casing 100 from the backwashing fixture.

[0024] like Figure 1 As shown, the negative pressure circulation backwashing process for aero-engines of the present invention firstly fixes the casing 100 to be washed onto a vibrating worktable inside a vacuum cleaning tank using a backwashing clamp, and seals the oil circuit interfaces of the casing 100 with the backwashing pipe ports; then, a vacuum negative pressure is formed in the vacuum cleaning tank by a vacuum pump, and the cleaning medium is injected into the tank through the backwashing pipe port and the spray pipe port until the casing 100 is completely submerged; next, the ultrasonic generator and the vibrating worktable are started, and the cleaning medium is extracted by a circulating filter pump and sprayed into the tank through the spray pipe port to form a spray cycle; after one return of liquid is completed, a vacuum cycle is performed again. The cleaning medium is introduced under negative pressure, then pumped out from the backwash port and sprayed into the spray port by a circulating filter pump. This creates a continuous reverse flow of the medium in the oil circuit of casing 100, moving from the original outlet to the inlet, achieving backwashing circulation. Subsequently, the cleaning medium in the oil circuit of casing 100 is drawn into the storage return tank by vacuum negative pressure. Throughout the rinsing process, an online particle size detection device monitors the particle concentration in the cleaning medium in real time. If the detection result does not meet the preset cleanliness standard, the process of introducing, spraying, backwashing, and returning the medium is automatically repeated until the standard is met. After that, the controller automatically shuts down all components and unloads the medium. This process, through vacuum negative pressure driving continuous reverse flow, ultrasonic vibration coupled peeling, and online detection closed-loop control, can effectively remove deposited particles in complex oil circuit corners and dead angles, achieving thorough cleaning and significantly improving the cleanliness compliance rate and batch consistency. At the same time, it achieves fully automated control, greatly improving cleaning efficiency.

[0025] The ultrasonic generator operates at a frequency of 25-30 kHz, while the vibration table operates at a frequency of 5-15 Hz. The ultrasonic generator's operating frequency is preferably controlled within the 25-30 kHz range. This frequency band generates a strong cavitation effect in the cleaning medium, forming numerous microbubbles that release instantaneous high-temperature, high-pressure shock waves upon rupture. This effectively removes excess particulate matter adhering to the inner cavity of the casing 100 and the oil passage walls. Simultaneously, the 5-15 Hz mechanical vibration of the vibration table works synergistically to create a coupled turbulent flow field within the complex oil passages. This allows the cleaning medium to penetrate deep into the corners and dead zones of variable-diameter, curved, and intersecting oil passages, thoroughly loosening and suspending deposited particles that traditional forward flushing cannot reach within the medium. This significantly improves the thoroughness of cleaning the complex casing 100 of the aero-engine.

[0026] The circulating filter pump performs multi-stage gradient filtration on the cleaning medium flowing through it, with the minimum pore size in the multi-stage gradient filtration being 4~6μm. By using a circulating filter pump to perform multi-stage gradient filtration on the cleaning medium flowing through it, and optimizing the minimum filtration pore size to be within 4~6μm, and by sequentially setting filtration stages from coarse to fine in the circulation path, it can efficiently intercept large particles and prevent filter clogging, while accurately capturing tiny particles to meet the cleanliness requirements of aero-engines. The filtered clean medium is then reinjected into the vacuum cleaning tank for circulation rinsing, avoiding secondary adhesion of particles inside the casing 100.

[0027] like Figure 3 As shown, during the initial liquid inlet process, a vacuum pump draws the gas from the vacuum cleaning tank to the gas-liquid separation tank, creating a vacuum negative pressure in the vacuum cleaning tank. The cleaning medium from the liquid return tank is then injected into the vacuum cleaning tank through the backwash port and spray port until the casing 100 is completely submerged, filling the inner cavity of the casing 100 and the cross-flow oil passages with the cleaning medium. Figure 4 As shown, during the spray cycle, the ultrasonic generator and vibrating worktable are activated. The cleaning medium in the vacuum cleaning tank is extracted by the circulating filter pump and sprayed into the vacuum cleaning tank through the spray nozzle. Figure 5 As shown, during the liquid return process, a vacuum pump draws gas from the liquid return tank to the gas-liquid separation tank, creating a vacuum negative pressure in the liquid return tank. A circulating filter pump then draws the cleaning medium from the vacuum cleaning tank into the liquid return tank. Figure 6 As shown, during the backwashing cycle, the cleaning medium is drawn from the backwashing port into the vacuum cleaning tank by the circulating filter pump and sprayed into the vacuum cleaning tank from the spray port, causing the cleaning medium to form a continuous reverse flow in the oil circuit of the casing 100 from the original oil outlet to the oil inlet. Figure 7As shown, during the secondary liquid return process, a vacuum pump draws the gas from the vacuum cleaning tank to the gas-liquid separation tank, creating a vacuum negative pressure in the vacuum cleaning tank. The cleaning medium in the oil circuit of casing 100 is drawn from the backwash port to the liquid storage return tank, and the cleaning medium in the vacuum cleaning tank is drawn to the liquid storage return tank by the circulating filter pump. Figure 8 As shown, during the unloading process, when the circulating filter pump is drawing the cleaning medium in the vacuum cleaning tank, the particle concentration in the cleaning medium is monitored in real time by an online particle size detection device, and the detection signal is fed back to the controller. When the particle concentration detection result does not meet the preset cleanliness standard, steps S2 to S7 are repeated; when the particle concentration detection result meets the preset cleanliness standard, the controller automatically shuts down the vacuum pump, circulating filter pump, ultrasonic generator and vibrating worktable, and removes the casing 100 from the backwashing fixture.

[0028] Example 2 This embodiment is the first embodiment of a backwashing system, including: A vacuum cleaning tank is used to contain the cleaning medium and immerse the casing 100. An ultrasonic generator and a vibrating worktable are installed inside the tank. The liquid return tank is sealed and connected to the vacuum cleaning tank, and is used to store and recover the cleaning medium; A circulating filter pump is connected between the vacuum cleaning tank and the liquid return tank to drive the cleaning medium to circulate. A vacuum pump is connected to a vacuum cleaning tank, a liquid storage reflux tank, and a gas-liquid separation tank to create a negative pressure environment. An online particle size detection device is installed on the connecting pipeline between the circulating filter pump and the vacuum cleaning tank to monitor the particle concentration of the cleaning medium in real time. The controller is connected to the online particle size detection device, vacuum pump, circulating filter pump, vibrating worktable, and ultrasonic generator to automatically control the rinsing process based on the particle size detection results.

[0029] like Figure 2As shown, the backwashing system of the present invention includes an ultrasonic generator and a vibrating worktable installed in a vacuum cleaning tank, with the casing 100 to be rinsed immersed in the cleaning medium. A vacuum pump is connected to the vacuum cleaning tank, the liquid storage return tank, and the gas-liquid separation tank to create a negative pressure environment within the system, driving the cleaning medium to flow continuously in the oil circuit of the casing 100 from the original oil outlet to the oil inlet. A circulating filter pump is connected between the vacuum cleaning tank and the liquid storage return tank, driving the cleaning medium to circulate and perform multi-stage gradient filtration. An online particle size detection device monitors the particle concentration of the cleaning medium in the circulating pipeline in real time and feeds the detection signal back to the controller. The controller automatically controls the start-up, shutdown, and process switching of the vacuum pump, circulating filter pump, vibrating worktable, and ultrasonic generator based on the particle size detection results. When the detection results do not meet the preset cleanliness standard, the controller controls the repeated execution of the liquid inlet, spraying, backwashing, and liquid return steps until the standard is met, and then automatically shuts down the system. This system achieves efficient removal of particles from complex oil passage dead zones and fully automated control through the synergistic effects of vacuum negative pressure driven reverse continuous flow, ultrasonic vibration coupled stripping, multi-stage gradient filtration, and online detection closed-loop control. It significantly improves the consistency and reliability of cleaning quality and meets the high cleanliness requirements of aero-engines.

[0030] The vacuum cleaning tank is equipped with spray nozzles on both sides for spray cleaning of the casing 100 surface; a backwash nozzle is located at the bottom of the vacuum cleaning tank for sealing connection with each oil passage interface of the casing 100 to achieve reverse suction cleaning. The spray nozzles are used for high-pressure spray cleaning of the casing 100 surface, effectively removing loose particles attached to the outer surface. The backwash nozzle is sealed to each oil passage interface of the casing 100 to achieve reverse suction cleaning. The two work together to ensure that the inner and outer surfaces of the casing 100 and the complex oil passages are simultaneously flushed by the cleaning medium. Spray cleaning ensures the outer surface is clean, while backwashing circulation penetrates deep into the oil passages to remove dead corner deposits. The combination of internal and external cleaning achieves all-round, dead-angle-free cleaning of the casing 100, significantly improving the overall cleanliness.

[0031] The vibrating worktable is slidably connected to the vacuum cleaning tank. A universal base for fixing the housing 100 is provided on the vibrating worktable, and a chip removal groove is formed on the universal base. A vibration source is installed below the vibrating worktable. Sliding the vibrating worktable to the vacuum cleaning tank facilitates quick loading and unloading of the housing 100 by operators, improving work efficiency. The universal base with the chip removal groove is provided on the worktable, and the housing 100 is clamped onto the base. The vibration source is installed below the worktable. When the vibrating worktable is started, mechanical vibration is transmitted to the housing 100 through the base, causing particles adhering to the inner wall to loosen and fall off. The detached particles fall directly into the chip removal groove and are promptly carried away by the cleaning medium, preventing secondary deposition or re-adsorption of particles at the bottom of the housing 100.

[0032] The circulating filter pump contains multiple sets of filter screens with progressively smaller pore sizes, all detachably connected to the pump. This gradient filtration structure, where large-pore screens first intercept large particles to protect downstream filters, while medium and small-pore screens gradually capture minute particles, thus meeting the high cleanliness requirements of aero-engines. The detachable connection between the filter screens and the pump facilitates quick disassembly, cleaning, and replacement, reducing maintenance difficulty and operating costs, and ensuring long-term stable operation of the filtration system.

[0033] Example 3 This embodiment is the first embodiment of the backwashing clamp, such as Figure 9 , Figure 10 As shown, the assembly includes a base plate 200, a connecting plate 300, a clamping assembly 400, and a first pipe connector 500. The base plate 200 is fixed to the vibrating worktable. The connecting plate 300 is disposed above the base plate 200 and is used to support the casing 100. The clamping assembly 400 is fixedly connected to the connecting plate 300 and is used to clamp and fix the casing 100 onto the connecting plate 300. The first pipe connector 500 is disposed on the clamping assembly 400 and includes an integrated liquid inlet box 510 and a liquid outlet 520. The liquid outlet 520 is connected to the backwash pipe port, and the integrated liquid inlet box 510 is connected to multiple oil circuit interfaces on the top surface of the casing 100.

[0034] like Figure 11 As shown, the backwashing fixture of the present invention, after fixing the base plate 200 on the vibrating worktable, mounts the housing 100 on the connecting plate 300, and then fixes the position of the housing 100 by the clamping assembly 400, so that the first pipe connector 500 is connected to the oil circuit interface of the housing 100. When the negative pressure circulation is started, the cleaning medium flows out from multiple oil circuit interfaces on the top surface of the housing 100, collects through the integrated liquid inlet box 510 to the liquid outlet 520 of the first pipe connector 500, and then enters the backwashing pipe port to realize multi-oil circuit reverse flushing. The fixture, through the design of the integrated liquid inlet box 510, connects multiple oil circuit interfaces on the top surface of the housing 100 with a single pipe connector, realizing the integration of multiple oil circuits with a single interface. It can simultaneously connect multiple oil circuit interfaces on the end face of the housing 100, greatly reducing the number of pipe connectors and the complexity of pipeline connection, and providing a stable clamping and installation effect for the negative pressure circulation backwashing process.

[0035] like Figure 9As shown, the clamping assembly 400 of this application includes a support rod 410 and a top pressure plate 420. The support rod 410 is connected to the connecting plate 300, and the top pressure plate 420 is detachably connected to the support rod 410. A first pipe connector 500 is disposed on the top pressure plate 420. During installation, the support rod 410 passes through the inside of the housing 100, and then the top pressure plate 420 is installed on top of the support rod 410, thereby clamping the housing 100. When the top pressure plate 420 clamps the top surface of the housing 100, the first pipe connector 500 automatically aligns and connects with multiple oil passage interfaces on the top surface of the housing 100, eliminating the need for separate pipe insertion operations, simplifying the clamping process, and shortening the installation time. At the same time, the detachable connection between the top pressure plate 420 and the support rod 410 facilitates quick replacement of the appropriate top pressure plate 420 according to different housing 100 models, improving the versatility of the fixture.

[0036] like Figure 12 , 13 As shown, the backwashing fixture in this embodiment also includes a side pressure plate 600, a second pipe connector 610, and a third pipe connector 700. The side pressure plate 600 is detachably installed on the side wall of the casing 100. The second pipe connector 610 is disposed on the side pressure plate 600 and connects the side oil passage of the casing 100 to the backwashing port. The third pipe connector 700 is disposed on the connecting plate 300 and connects the bottom oil passage of the casing 100 to the backwashing port. This multi-directional pipe connector layout enables the simultaneous completion of backwashing connections for all oil passages on the top, bottom, and side walls of the casing 100 in a single clamping configuration, eliminating the need for multiple clamping operations for oil passages in different orientations, as is required with traditional fixtures.

[0037] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0038] 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 negative pressure circulation backwashing process for aircraft engines, characterized in that, Includes the following steps: S1. Clamping and fixing: Fix the casing (100) to be rinsed to the vibrating worktable in the vacuum cleaning tank using the backwashing clamp, and seal and connect each oil circuit interface of the casing (100) to the backwashing pipe port, so that the spray pipe port is aligned with the casing (100). S2, First liquid injection: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the storage return tank is injected into the vacuum cleaning tank through the backwash port and the spray port until the casing (100) is completely submerged, so that the cleaning medium fills the inner cavity of the casing (100) and the cross oil passages. S3, Spraying Circulation: Start the ultrasonic generator and the vibrating worktable, extract the cleaning medium from the vacuum cleaning tank through the circulating filter pump, and spray it into the vacuum cleaning tank through the spray nozzle to form a spraying circulation. S4, First return of liquid: The gas in the liquid storage return tank is drawn into the gas-liquid separation tank by a vacuum pump, and a vacuum negative pressure is formed in the liquid storage return tank. The cleaning medium in the vacuum cleaning tank is drawn into the liquid storage return tank by a circulating filter pump. S5, Secondary liquid injection: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the storage return tank is injected into the vacuum cleaning tank through the backwash port and the spray port until the casing (100) is completely submerged, so that the cleaning medium fills the inner cavity of the casing (100) and the cross oil passages. S6. Backwashing circulation: The cleaning medium is drawn out of the vacuum cleaning tank from the backwashing port by the circulating filter pump and sprayed into the vacuum cleaning tank from the spray port, so that the cleaning medium forms a continuous reverse flow from the original oil outlet to the oil inlet in the oil circuit of the casing (100). S7, Secondary return of liquid: The gas in the vacuum cleaning tank is drawn into the gas-liquid separation tank by the vacuum pump, and a vacuum negative pressure is formed in the vacuum cleaning tank. The cleaning medium in the oil circuit of the casing (100) is drawn into the liquid storage return tank from the backwash port. The cleaning medium in the vacuum cleaning tank is drawn into the liquid storage return tank by the circulating filter pump. S8. Unloading detection: When the circulating filter pump draws the cleaning medium in the vacuum cleaning tank, the particle concentration in the cleaning medium is monitored in real time by an online particle size detection device, and the detection signal is fed back to the controller. When the particle concentration detection result does not meet the preset cleanliness standard, the steps S2 to S7 are repeated. When the particle concentration detection result meets the preset cleanliness standard, the controller automatically shuts down the vacuum pump, circulating filter pump, ultrasonic generator and vibrating worktable, and removes the casing (100) from the backwashing fixture.

2. The negative pressure circulation backwashing process for aero-engines according to claim 1, characterized in that, The ultrasonic generator operates at a frequency of 25-30 kHz, and the vibrating worktable operates at a frequency of 5-15 Hz.

3. The negative pressure circulation backwashing process for aero-engines according to claim 1, characterized in that, The circulating filter pump performs multi-stage gradient filtration on the cleaning medium flowing through it, and the minimum pore size in the multi-stage gradient filtration is 4~6μm.

4. A backwashing system for implementing the negative pressure circulation backwashing process of an aero-engine as described in any one of claims 1 to 3, characterized in that, include: A vacuum cleaning tank is used to contain the cleaning medium and immerse the casing (100), and an ultrasonic generator and a vibrating worktable are installed inside it. A liquid reflux tank is sealed and connected to the vacuum cleaning tank, and is used to store and recycle the cleaning medium; A circulating filter pump is connected between the vacuum cleaning tank and the liquid return tank to drive the cleaning medium to circulate. A vacuum pump is connected to a vacuum cleaning tank, a liquid storage reflux tank, and a gas-liquid separation tank to create a negative pressure environment. An online particle size detection device is installed on the connecting pipeline between the circulating filter pump and the vacuum cleaning tank to monitor the particle concentration of the cleaning medium in real time. The controller is connected to the online particle size detection device, vacuum pump, circulating filter pump, vibrating worktable, and ultrasonic generator to automatically control the rinsing process based on the particle size detection results.

5. The backwashing system according to claim 4, characterized in that, The vacuum cleaning tank is provided with spray nozzles on both sides for spraying and cleaning the surface of the casing (100); the bottom of the vacuum cleaning tank is provided with a backwash nozzle for sealing connection with each oil circuit interface of the casing (100) to achieve reverse suction.

6. The backwashing system according to claim 4, characterized in that, The vibrating worktable is slidably connected to the vacuum cleaning tank. A universal base for fixing the casing (100) is provided on the vibrating worktable. A chip removal groove is provided on the universal base. A vibration source is installed below the vibrating worktable.

7. The backwashing system according to claim 4, characterized in that, The circulating filter pump has multiple sets of filter screens with progressively smaller pore sizes arranged inside it, and the filter screens are detachably connected to the circulating filter pump.

8. A backwashing fixture for the negative pressure circulation backwashing process of an aero-engine as described in any one of claims 1 to 3, characterized in that, The assembly includes a base plate (200), a connecting plate (300), a clamping assembly (400), and a first pipe connector (500). The base plate (200) is fixed to the vibrating worktable. The connecting plate (300) is disposed above the base plate (200) and is used to support the casing (100). The clamping assembly (400) is fixedly connected to the connecting plate (300) and is used to clamp and fix the casing (100) onto the connecting plate (300). The first pipe connector (500) is disposed on the clamping assembly (400). The first pipe connector (500) includes an integrated liquid inlet box (510) and a liquid outlet (520). The liquid outlet (520) is connected to the backwash pipe port. The integrated liquid inlet box (510) is connected to multiple oil circuit interfaces on the top surface of the casing (100).

9. The backwashing clamp according to claim 8, characterized in that, The clamping assembly (400) includes a support rod (410) and a top pressure plate (420). The support rod (410) is connected to the connecting plate (300), and the top pressure plate (420) is detachably connected to the support rod (410). The first pipe joint (500) is disposed on the top pressure plate (420).

10. The backwashing clamp according to claim 8, characterized in that, It also includes a side pressure plate (600), a second pipe connector (610), and a third pipe connector (700). The side pressure plate (600) is detachably installed on the side wall of the casing (100). The second pipe connector (610) is disposed on the side pressure plate (600) and connects the side oil passage of the casing (100) to the backwash port. The third pipe connector (700) is disposed on the connecting plate (300) and connects the bottom oil passage of the casing (100) to the backwash port.

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