An aero gear class component cleanliness control method

Abstract

The present application belongs to the field of mechanical processing, and discloses an aviation gear part cleanliness control method. The method comprehensively identifies and classifies the cleanliness risk points in the whole processing process, divides the risk points into three key stages of pretreatment, intermediate treatment and packaging, and takes targeted treatment measures: the initial pollution is effectively removed through polishing and oil stain particle cleaning in the pretreatment stage; the ultrasonic cleaning is combined with the finishing machining to deeply clean and protect the part surface in the intermediate treatment stage, and the part box protective tool is adopted to minimize the secondary pollution in the circulation process; the final cleanliness is ensured through demagnetization, residual magnetism inspection and three-step cleaning method before packaging, and the grade is strictly evaluated. The method not only greatly improves the automation degree and cleaning efficiency, significantly improves the cleaning effect, reduces the cleaning cost, realizes the whole-process cleanliness control from part processing to packaging, and ensures that the cleanliness of the aviation gear parts meets the strict requirements in the aviation field.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of machining, in particular to the field of cleanliness control of aviation parts, and particularly relates to a method for controlling cleanliness of aviation gear parts. BACKGROUND

[0002] Cleaning is a very important link in modern manufacturing production, and effective cleaning is one of the key factors to ensure the final quality of products. Cleanliness is an index for representing the cleaning level of parts, and is also the limit value of residual particle pollutants on the surface of parts after cleaning, involving particle pollutant types, size, quantity and quality, etc. With the rapid improvement of modern manufacturing process level, cleaning technology is paid more and more attention and is widely used in many industries such as aerospace, vehicles, medical devices, etc. In the field of aviation, specifically in the field of many parts of aviation engines, cleanliness has a more obvious influence on the service life of bearings, pumps, valves, gears and other fuel and lubricating oil systems and moving parts, and the service life of parts with uncontrolled cleanliness and controlled cleanliness can differ by several times or even more than several dozen times, which can also have a great impact on the machining precision and use performance of parts, and to some extent, it is related to the quality of the entire aviation engine product.

[0003] At present, the cleaning process for hydraulic, fuel and lubricating systems on the aircraft mostly uses manual or semi-automatic soaking ultrasonic cleaning, which has low automation degree, poor cleaning effect, low efficiency and high cleaning cost, and the cleaning quality is difficult to meet higher cleanliness standard requirements; more importantly, the traditional cleanliness control process only stays in the cleaning process of parts and cleanliness detection at individual links, and cannot achieve cleanliness control in the whole process, resulting in uncontrolled cleanliness of parts and failure to meet the cleanliness grade requirements of aviation parts.

[0004] Therefore, the existing cleanliness control method is limited to the cleaning process of parts and cleanliness detection at individual links, and cannot achieve cleanliness control in the whole process, resulting in uncontrolled cleanliness of parts. SUMMARY

[0005] The present application aims to provide a method for controlling cleanliness of aviation gear parts to solve the technical problem that the existing cleanliness control method is limited to the cleaning process of parts and cleanliness detection at individual links, and cannot achieve cleanliness control in the whole process, resulting in uncontrolled cleanliness of parts.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] A method for controlling cleanliness of aviation gear parts, comprising:

[0008] The cleanliness risk points existing in the whole machining process of the aero gear parts are acquired;

[0009] All the cleanliness risk points are divided into pretreatment risk points, intermediate treatment risk points and pre-packaging risk points;

[0010] For the pretreatment risk points, the aero gear parts are treated by polishing and oil stain particle cleaning in turn;

[0011] For the intermediate treatment risk points, the aero gear parts are treated by ultrasonic cleaning and finishing in turn; wherein, the aero gear parts are protected by a part box tool during the circulation of the aero gear parts;

[0012] For the pre-packaging risk points, the aero gear parts are treated by removing magnetism, residual magnetism inspection and three-step cleaning method in turn, and the cleanliness grade of the aero gear parts is evaluated after cleaning.

[0013] Further, the cleanliness risk points include the following categories:

[0014] The first category, burrs are generated during the machining process of the aero gear parts, such as turning, grinding, gear hobbing and gear grinding, and the burrs are not completely removed, so there is a risk of burr residue;

[0015] The second category, particles are attached to the surface of the aero gear parts before heat treatment, and the tiny particles are coated during the heat treatment process, so there is a risk of falling out later;

[0016] The third category, there is a risk of bringing in foreign matter during the magnetic flaw detection process;

[0017] The fourth category, there is a risk of foreign matter and fiber residue on the aero gear parts before machining inspection;

[0018] The fifth category, there is a risk of environmental pollution during the circulation and packaging process of the aero gear parts;

[0019] The sixth category, there is a risk of residual metal powder attachment during the machining process of the aero gear parts;

[0020] The seventh category, there is a risk of incomplete cleaning due to improper arrangement of the cleaning process.

[0021] Further, the cleanliness risk points also include:

[0022] The eighth category, there is a problem of bumping of the aero gear parts during the packaging process.

[0023] Further,

[0024] The cleaned aero gear parts are packaged by gas phase packaging method.

[0025] Further, the specific steps of treating the aero gear parts by polishing and oil stain particle cleaning in sequence for the pretreatment risk points are as follows:

[0026] The sand wheel and the file are used to remove the tooth part along the tooth top circle and the end face of the aero gear parts, and the tooth profile is polished to R0.2max, and the remaining parts are polished to R0.3max; meanwhile, the felt wheel polishing method is used to remove the residual burrs at the tooth profile transition;

[0027] After the polishing treatment, the stereo microscope is used to detect the residual burrs of the aero gear parts;

[0028] The oil stain particle removal method adopts the processes of soaking, rinsing and compressed air drying, and is used to remove the oil stains and metal particles attached to the surface of the aero gear parts before heat treatment, and to clean the aero gear parts before and after magnetic detection, so as to remove the residual liquid;

[0029] After the cleaning by the oil stain particle cleaning method, the surface of the aero gear parts is inspected by visual method.

[0030] Further, the specific steps of treating the aero gear parts by ultrasonic cleaning and finishing in sequence for the intermediate treatment risk points are as follows:

[0031] The processes of soaking, rinsing, single-tank ultrasonic cleaning and compressed air drying are used to remove the foreign matters and fiber residues of the aero gear parts before entering the machining detection;

[0032] After the removal of the foreign matters and fiber residues, the surface of the aero gear parts is inspected by visual method.

[0033] Further, the specific process of the single-tank ultrasonic cleaning includes:

[0034] The water-based cleaning agent and deionized water are mixed and put into the single-tank ultrasonic cleaning machine;

[0035] The single-tank ultrasonic cleaning machine is set to a cleaning frequency of 40-45KHz, a cleaning time of 3-5min and a heating temperature of 40-55℃;

[0036] The aero gear parts are put into the single-tank ultrasonic cleaning machine to complete the single-tank ultrasonic cleaning;

[0037] After the finishing of the aero gear parts, the finishing treatment is performed on the parts by the finishing method to reduce the burrs and metal chip residues.

[0038] Further, for the risk point before packaging, the magnetic removal, residual magnetic inspection method and three-step cleaning method are sequentially adopted to process the aviation gear parts, and the specific steps of evaluating the cleanliness level of the aviation gear parts after cleaning are as follows:

[0039] The aviation gear parts are subjected to demagnetization treatment, and after demagnetization, a residual magnetic inspection is performed using a magnetometer, and the residual magnetic inspection qualified standard is that the residual magnetic value is less than or equal to 3GS;

[0040] The three-step cleaning method is adopted to process the aviation gear parts, and the specific steps are as follows:

[0041] The aviation gear parts after residual magnetic inspection are sequentially subjected to pre-cleaning, through cleaning and composite cleaning; wherein the ultrasonic frequencies corresponding to the pre-cleaning, through cleaning and composite cleaning are sequentially reduced to remove residual particles of different sizes;

[0042] The cleanliness level of the cleaned aviation gear parts is detected to realize cleanliness level evaluation.

[0043] Further, the specific steps of sequentially performing pre-cleaning, through cleaning and composite cleaning on the aviation gear parts after residual magnetic inspection are as follows:

[0044] The single-slot ultrasonic wave with an ultrasonic frequency of 40-45KHz is adopted to pre-clean the aviation gear parts after residual magnetic inspection;

[0045] The multi-slot ultrasonic wave with an ultrasonic frequency of 28-35KHz is adopted to through-clean the aviation gear parts;

[0046] The vacuum low-frequency ultrasonic rough cleaning, vacuum low-frequency ultrasonic fine cleaning and high-vacuum drying method are adopted to composite clean the aviation gear parts.

[0047] Further, the multi-slot ultrasonic wave adopts six-slot ultrasonic wave, and the filtration accuracy of the six slots is from 50um to 5um.

[0048] Compared with the prior art, the present application has the following beneficial effects:

[0049] The application provides an aviation gear part cleanliness control method, which comprehensively identifies and classifies the cleanliness risk points in the whole processing process, divides the risk points into three key stages of pretreatment, intermediate treatment and pre-packaging, and adopts targeted treatment measures: the initial pollution is effectively removed through polishing and oil particle cleaning in the pretreatment stage; the ultrasonic cleaning is combined with the finishing machining to deeply clean and protect the part surface in the intermediate treatment stage, and the part box protector is used to minimize the secondary pollution in the circulation process; the final cleanliness is ensured through demagnetization, residual magnetism inspection and three-step cleaning method before packaging, and the grade is strictly evaluated. The method can greatly improve the automation degree and cleaning efficiency, significantly improve the cleaning effect, reduce the cleaning cost, realize the whole-process cleanliness control from part processing to packaging, ensure that the cleanliness of the aviation gear parts meets the strict requirements of the aviation field, and solve the problems of insufficient automation, poor cleaning effect, low efficiency and uncontrollable cleanliness in the traditional cleanliness control method.

[0050] Preferably, in the application, a plurality of cleanliness risk point categories are provided; the subsequent cleaning measures are provided with clear guidance direction; the classification and identification method helps to fully understand and master the difficulties and key points of cleanliness control, so that more effective cleaning strategies are developed.

[0051] Preferably, in the application, the knocking problem in the packaging process enriches the cleanliness risk point categories, which helps to avoid secondary pollution and damage to the parts in the packaging stage, and improves the overall quality and reliability of the product.

[0052] Further preferably, in the application, the gas phase packaging method is adopted, which can effectively prevent the aviation gear parts from being polluted during storage and transportation, maintain the cleanliness and performance stability of the parts, and prolong the service life of the product.

[0053] Preferably, in the application, specific polishing and oil particle cleaning steps are proposed for the pretreatment risk points, which can completely remove burrs and oil particles on the surface of the parts, provide a good foundation for subsequent processing and cleaning, and ensure the cleanliness and processing quality of the parts.

[0054] Preferably, in the application, in the intermediate treatment stage, the ultrasonic cleaning and visual inspection are combined to effectively remove foreign matter and fiber residues on the surface of the parts, improve the cleanliness and surface quality of the parts, and provide protection for subsequent processing and assembly.

[0055] Preferably, in the present application, the specific process of single-tank ultrasonic cleaning, including the selection of cleaning agent, the setting of cleaning frequency, time and temperature, and the method of finishing, can further improve the cleanliness and surface quality of the parts to meet the high standards of parts in the aviation field.

[0056] Preferably, in the present application, in the pre-packaging stage, the magnetic and residual magnetic materials and residual particles on the parts are completely removed through demagnetization, residual magnetic inspection and three-step cleaning method, ensuring the cleanliness and non-magnetic of the parts and meeting the special requirements of parts in the aviation field.

[0057] Further preferably, in the present application, the specific steps of three-step cleaning method and the selection of ultrasonic frequency can effectively remove different sizes of residual particles, improve the efficiency and effect of cleaning, and ensure the cleanliness of parts to meet the aviation standards; at the same time, the use of different ultrasonic frequency oscillation greatly improves the cleaning effect.

[0058] More preferably, in the present application, six-tank ultrasonic cleaning is used for through cleaning, and the filtration precision of each tank is different, which can gradually remove particles of different sizes, improve the fineness and efficiency of cleaning, and ensure the cleanliness and surface quality of the parts; at the same time, the use of six-tank ultrasonic cleaning also improves the automation and stability of cleaning, reduces the difficulty and cost of manual operation. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 The cleanliness risk point diagram in the whole machining process of the aviation gear parts provided by the embodiment of the present application;

[0060] Figure 2 The tooth profile diagram of the aviation gear parts under the stereomicroscope provided by the embodiment of the present application;

[0061] Figure 3 The flowchart of the cleanliness control method of the aviation gear parts provided by the embodiment of the present application;

[0062] Figure 4 The specific flowchart of through cleaning in the cleanliness control method of the aviation gear parts provided by the embodiment of the present application. DETAILED DESCRIPTION

[0063] In order to make the technical solutions in the present application better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts should fall within the scope of protection of the present application.

[0064] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can be intervening elements. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can be present. The terms "vertical", "horizontal", "left", "right", and the like as used herein are used for illustration only and are not intended to be limiting.

[0065] Embodiment 1

[0066] As mentioned in the background, the cleaning methods include manual cleaning and equipment cleaning, wherein the manual cleaning includes immersion cleaning (soaking brushing), scrubbing, rinsing, etc.; the equipment cleaning mainly includes jet cleaning, ultrasonic cleaning, high-flow flushing, combined cleaning, etc. The ultrasonic cleaning principle is mainly applied in the equipment cleaning. The ultrasonic cleaning is to use the cavitation effect of the ultrasonic vibrator in the cleaning tank to destroy the contaminants on the workpiece surface, accelerate the dissolution or peeling of the contaminants to achieve the purpose of removing the contaminants. This cleaning method has remarkable effect and simple operation, but only relying on single ultrasonic cleaning of parts cannot meet the requirements of high-precision and high-cleanliness grade parts. For the gear parts proposed in the present embodiment, in addition to the requirements of pressure resistance, wear resistance, impact resistance, plastic deformation resistance, surface contact fatigue resistance and bending fatigue resistance, the gear parts also require higher anti-pollution ability; therefore, higher requirements are put forward for the cleanliness of the gear parts.

[0067] As can be seen, the existing cleanliness control method is limited to the cleaning process of the parts and the cleanliness detection at individual links, and cannot achieve the cleanliness control in the whole process, resulting in uncontrolled cleanliness of the parts; therefore, it is necessary to improve the traditional cleaning process to achieve the goal of high-efficiency and high-quality cleaning of the parts, and to improve the working environment and reduce energy consumption.

[0068] In order to solve the above problems and achieve the above purposes, the embodiment provides an aviation gear part cleanliness control method. The method can be combined with the structure characteristics of the parts and the related technical requirements according to the existing cleaning technology and the actual conditions on the site, the cleanliness standards of the parts are marked, the cleanliness control risk points are found out from the whole machining process of the parts, and the cleanliness control process suitable for the high-precision gear parts is finally formed, so that the high-precision gear parts can meet the corresponding cleanliness grade requirements.

[0069] As shown in Figure 3 , the embodiment provides an aviation gear part cleanliness control method, and the specific steps are as follows:

[0070] Obtaining the cleanliness risk points existing in the whole machining process of the aviation gear parts;

[0071] Dividing all the cleanliness risk points into pretreatment risk points, intermediate treatment risk points and pre-packaging risk points;

[0072] For the pretreatment risk points, the aviation gear parts are treated by adopting the polishing and oil stain particle cleaning modes in sequence;

[0073] For the intermediate treatment risk points, the aviation gear parts are treated by adopting the ultrasonic cleaning and finishing machining modes in sequence; wherein, the aviation gear parts are protected by adopting the part box protector in the turnover process of the aviation gear parts;

[0074] For the pre-packaging risk points, the aviation gear parts are treated by adopting the demagnetization and residual magnetism inspection modes, three-step cleaning method in sequence, and the cleanliness grade of the aviation gear parts is evaluated after the cleaning is completed.

[0075] In order to facilitate understanding of the above control method mentioned in the embodiment, the specific description is as follows:

[0076] The embodiment provides a high-precision gear part cleanliness control process which is a through cleaning, vacuum ultrasonic rotary spray composite cleaning and vacuum drying process with (deionized water + water-based cleaning agent) and hydrocarbon solvent as cleaning medium; the machining process of the gear parts is as shown in Figure 1 According to the machining process of the parts, the identified cleanliness control process risk points (also called cleanliness risk points) are marked by serial numbers ① to ⑧ in Figure 1 , and the cleanliness risk point analysis is as follows:

[0077] Serial number ①: burrs are generated in the machining process of the turning, grinding, gear hobbing and gear grinding, and the burrs are not completely removed in the deburring process, so that there is a risk of small burr residue;

[0078] No. 2: Before heat treatment, the surface of the part is attached with small particles, which are coated during the heat treatment process, and there is a risk of falling off later;

[0079] No. 3: There is a risk of bringing in foreign matter during magnetic flaw detection;

[0080] No. 4: There are small foreign objects, fibers and other residues on the part before inspection;

[0081] No. 5: The environment pollution and other factors during the part turnover, packaging and other processes cause the cleanliness of the part to fail to meet the requirements, that is, the whole process control;

[0082] No. 6: There is residual magnetism during the part processing process, and the part is attached with residual metal powder, which is difficult to clean;

[0083] No. 7: The arrangement of the cleaning process is unreasonable; adjust the cleaning process according to different ultrasonic frequencies;

[0084] No. 8: There is a slight bump problem during the transfer process of the packaged part, which causes the cleanliness of the part to fail to meet the requirements.

[0085] For the above-mentioned 8 kinds of cleanliness risk points, the cleanliness control process of each risk point is as follows:

[0086] For cleanliness risk point ①, use grinding wheel and file to remove the tooth top circle and end face tooth profile grinding circle R0.2 max of the tooth part, and increase felt wheel polishing to remove the residual small burrs at the tooth profile transition, as shown in Figure 2 , and check the gear for burr residues under the stereomicroscope; wherein R0.2 max means that during the grinding or processing process, an edge or corner needs to be ground into a circular arc shape, and the maximum value of the radius of this circular arc shall not exceed 0.2 millimeters, and the grinding circle R0.3 max is the same as R0.2 max.

[0087] For cleanliness risk points ② and ③, mainly use soaking + rinsing + compressed air drying cleaning process to remove oil stains, metal particles and other foreign matters attached to the surface of the part before heat treatment; clean before and after magnetic detection to improve detection quality and remove residual liquid.

[0088] After cleaning, visually check the part surface for no particles, metal chips and other foreign matters.

[0089] Cleaning process: manual loading-soaking, rinsing-manual unloading-compressed air drying;

[0090] Among them, single tank soaking and rinsing tank are used, and the cleaning medium is solvent cleaner, and the solvent cleaner is preferably metalsolv3010; the equipment cleaning time is 3-5 min.

[0091] For cleanliness risk point IV, the soaking cleaning + single-tank ultrasonic cleaning + compressed air drying cleaning process is mainly used to remove the small foreign objects, fibers and other objects attached to the surface of the parts before inspection, and to improve the first-time detection pass rate of the part appearance.

[0092] After cleaning, visually inspect the part surface for no particulate matter, metal chips and other foreign objects.

[0093] Cleaning process: manual loading - ultrasonic cleaning (40-45KHz) - manual unloading - compressed air drying;

[0094] Among them, the single-tank ultrasonic cleaning machine is used to complete the cleaning, and the ultrasonic generator uses a fixed frequency of 40-45KHz; the cleaning medium is water-based cleaning agent (preferably SKH-232) + deionized water, and the ratio of the two is 3% Vol; the specific equipment cleaning time is 3-5min; the heating temperature is 40-55℃.

[0095] For cleanliness risk point V, protective devices such as part boxes are used to prevent the aviation gear parts from being damaged and causing secondary pollution during the turnover process.

[0096] For cleanliness risk point VI, demagnetization + residual magnetism inspection before final cleaning is mainly used, and a magnetometer is used for inspection; residual magnetism not greater than 3GS is considered to pass the inspection.

[0097] For cleanliness risk point VII, the cleaning method before the final storage of the parts needs to be clarified. In this embodiment, the cleaning mechanism of ultrasonic waves is studied. Unlike the single-frequency ultrasonic wave used in traditional cleaning processes, different ultrasonic frequencies are used to clean parts according to the cleaning ability of different ultrasonic frequencies on the size of residual particles, and the final cleaning process before the final storage of gear parts is developed, as follows:

[0098] First step: pre-cleaning of the aviation gear parts after residual magnetism inspection using single-tank ultrasonic waves with a frequency of 40-45KHz;

[0099] Second step: through cleaning: a cleaning process that removes contaminants such as rust-proof grease, cutting fluid, metal dust, dust, and grinding paste from the surface of the workpiece and dries it through a series of processes such as ultrasonic cleaning, spraying, ultrasonic cleaning, rinsing, hot air drying, and vacuum drying. The specific process and related parameters are shown in Figure 4 .

[0100] (1) The side and bottom of the tank are equipped with ultrasonic transducers, and the ultrasonic generator uses a fixed frequency of 28-35KHz.

[0101] (2) Cleaning medium: deionized water, deionized water + water-based cleaning agent (SKH-232), cleaning agent concentration ratio is 3% Vol.

[0102] After cleaning, visually inspect the part surface for no particulate matter, metal chips and other foreign matter.

[0103] The third step of composite cleaning: the solvent treatment system used in the entire cleaning process is operated under vacuum (<100 mbar), and the combination process of composite cleaning technology is used to alternately use solvent and water-based cleaning medium in one cleaning chamber, so that the workpiece can effectively remove organic and inorganic matter and dry in the cleaning chamber.

[0104] (1) Ultrasonic generator frequency 20-25 KHz;

[0105] (2) Cleaning medium: solvent ISOPARTML FLUID (Exxon Mobil), deionized water + water-based cleaning agent (BONDERITE C-NE 5088).

[0106] In this embodiment, the composite cleaning machine has a total of 4 liquid storage tanks, of which tank 1 and tank 2 are solvent tanks, and tank 11 and tank 12 are deionized water tanks. Through programming control, single cleaning or composite cleaning function can be realized, and during the cleaning process, functions such as turning on / off ultrasonic waves and opening / closing basket swing can be selected. Finally, for gear parts cleaning, program 5 (tank 11-tank 12-tank 1-tank 2-drying) is selected for cleaning after multiple cleaning verification, and after cleaning, it is sent to cleanliness detection.

[0107] For cleanliness risk point ⑧, there is a problem of slight bumping during the transfer process of the packaged parts, which causes the cleanliness of the parts to be unable to meet the requirements. Therefore, a warehouse packaging protection device is specially customized, which can effectively prevent the cleaned parts from being bumped and avoid the re-introduction of contaminants.

[0108] In this embodiment, the cleanliness level is divided as shown in Table 1:

[0109] Table 1 is the cleanliness level division

[0110]

[0111] Detect and record the number of 5-15 μm, 15-25 μm, 25-50 μm, and 50-100 μm solid particles in the residual contaminants on the controlled surface of the parts. The number of particles detected is converted to the number of particles per 1000 cm2 of controlled surface according to the particle size classification listed in the table above.

[0112] The conversion formula is: conversion quantity = detection quantity x 1000 / controlled surface area measured in square centimeters, and then compare the conversion quantity with Table 1 to determine the actual cleanliness grade of the part. Cleanliness identification example: B8 / C7 / D6 / E5 / F4.

[0113] Currently, the cleanliness grade requirement of gear parts is: AETF1-D8 / E7 / F7, and no solid particles greater than 200 μm should exist.

[0114] The embodiment provides an aviation gear part cleanliness control method, which has the following characteristics:

[0115] (I) Different cleaning stages use different cleaning media (solvent cleaning agent, water-based cleaning agent) to exert their respective advantages. The solvent cleaning agent has strong heavy oil removal ability, so it is arranged in the pretreatment stage and the soaking and brushing stage in the intermediate treatment; the water-based cleaning agent has good ultrasonic effect, so it is arranged in the precision cleaning process after soaking and heavy oil removal in the intermediate treatment, including the cleaning process of the compound machine, which is also a cleaning program that selects solvent cleaning and water-based cleaning alternately to clean the parts thoroughly.

[0116] (II) Different frequency cleaning equipment is arranged in different cleanliness control stages. According to the different removal abilities of residual particles of different sizes according to the ultrasonic frequency, 40-45 KHz, 28-35 KHz, and 20-25 KHz oscillation type ultrasonic cleaning is used to remove residual particles of different sizes in the intermediate treatment stage and the packaging pretreatment process.

[0117] (III) Demagnetization treatment: The magnetism generated during part processing or inherent in the part is removed before final storage to reduce the cleaning difficulty.

[0118] (IV) In terms of rust prevention, the final cleaning of the part is arranged on a compound cleaning machine with drying function (vacuum low-frequency ultrasonic rough cleaning, vacuum low-frequency ultrasonic precision cleaning, and high-vacuum drying) to ensure thorough drying, so as to prevent rust caused by incomplete drying of the part after cleaning.

[0119] (V) In terms of product protection, different protective devices are customized according to the structural characteristics of the part to avoid scratches during part turnover and secondary pollution.

[0120] (VI) After packaging, gas phase packaging is used to realize pre-assembly cleaning-free, avoid secondary pollution, and save cost.

[0121] It can be seen that the embodiment provides an aviation gear part cleanliness control method, that is, a cleanliness control process flow of high-precision gear parts in an aero-engine control system. The flow includes three stages of pretreatment, intermediate treatment, and pre- and post-treatment, and through different cleaning stages, different cleaning media are used. Different frequency cleaning equipment is arranged in different cleanliness control stages. Demagnetization treatment before packaging cleaning; effective rust prevention; in product protection, different protection instruments are customized; after packaging, the gas phase packaging method is used, which can realize pre-assembly cleaning-free, thereby saving cost and other details. Finally, the corresponding cleanliness grade requirement of the parts is achieved, and the full-process cleanliness control of high-precision gear parts is realized. The method can meet the cleanliness grade requirement of high-precision gear parts. At present, the cleanliness control process flow of high-precision gear parts has been solidified and applied to actual production, and the cleaning time of gear parts to the standard requirement grade is shortened by 87%, and the cleaning effect is improved by 6 times. The design of the cleanliness control process flow of high-precision gear parts in the aero-engine control system can be popularized to the cleanliness control process flow of other parts.

[0122] Embodiment 2

[0123] The embodiment provides a specific implementation application for the aviation gear part cleanliness control method provided in embodiment 1, and is as follows.

[0124] The specific implementation steps are as follows:

[0125] Taking the oil pump gear part XX-00-04 as an example, after the burr control in the mechanical processing process, such as active deburring in the turning process, manual deburring, and finishing process control, the cleanliness control cleaning flow of the cleanliness risk points in other processes is as follows:

[0126] (1) The following cleaning flow is used between processes:

[0127] Soak and brush clean → rinse → dry with compressed air.

[0128] (2) The following cleaning flow is used before cooperation:

[0129] Rinse → dry with compressed air.

[0130] (3) The following cleaning flow is used before process inspection:

[0131] Soak and brush clean → single-tank ultrasonic cleaning → dry with compressed air.

[0132] (4) The cleaning flow before process inspection: rotary spray cleaning.

[0133] (5) After the process cleaning control, check under the stereomicroscope whether there is burr residue before the final cleaning, and finally perform the final cleaning before storage, packaging control, and final cleaning before storage, which includes rough cleaning and fine cleaning, and the main control steps are as follows:

[0134] (1) Demagnetization and inspection, check the magnetism before demagnetization; when greater than 3GS, demagnetize in the demagnetization machine, and check that the residual magnetism should be not greater than 3GS.

[0135] (2) Receive the parts, confirm the number of parts and check that the parts should be free of burrs, grinding paste residue, visible particulate matter, scratches, and bumps.

[0136] (3) Pre-washing machine cleaning: put the parts from the part box into the cleaning basket; according to the preset program, clean in tank 1 and tank 2 respectively, and then use the shower nozzle to wash each part in tank 3.

[0137] (4) Compound cleaning machine cleaning:

[0138] When using the compound cleaning machine, according to the preset program, the cleaning process is as follows:

[0139] Use program 5: tank 11-tank 12-tank 1-tank 2-dry.

[0140] (5) Single-tank ultrasonic cleaning: ① Single-tank ultrasonic cleaning for 3-5 min → ② Use compressed air to dry.

[0141] (6) Visual inspection: under the environment with illumination not less than 1100 (lx), take the parts with rubber gloves, visually inspect whether there is visible particulate matter, and then put the parts from the cleaning basket into the part box. Extract the parts that meet the cleaning area to detect the cleanliness, and the final test results are as follows: AETF1A-D3 / E5 / F4.

[0142] It should be noted that the present application also provides embodiments for different types of parts based on the control method, and the specific implementation measures are as follows:

[0143] (1) Similar part structure

[0144] For similar structure parts, the cleanliness control process can refer to the cleanliness control process in the example.

[0145] (2) Parts with surface treatment requirements

[0146] For parts with surface treatment requirements, the main treatment principle is that surface treatment parts cannot be ultrasonically cleaned for a long time. The ultrasonic cleaning time can be reduced by adjusting the program. At the same time, parts with surface treatment, especially parts containing plating layers such as galvanized passivation, cadmium plating passivation, cadmium titanium plating passivation, chromium plating and the like cannot be cleaned at high temperature. Therefore, when selecting the cleaning process, the influence of high temperature on the surface treatment layer should be avoided. For parts with coating layer, in order to avoid the coating layer from falling off, ultrasonic cleaning method cannot be used. Ultrasonic cleaning can be performed on the equipment before coating, and manual scrubbing method can be directly used after coating.

[0147] (3) Different materials of parts

[0148] For parts of easy rust material, water-based cleaning process should be avoided as much as possible, that is, in the present application, the water-based cleaning time can be shortened and dried in time, or the composite machine solvent cleaning process can be directly used.

[0149] It can be seen that the present application provides an aviation gear part cleanliness control method, which has the following advantages compared with the existing cleanliness control measures:

[0150] The present method systematically identifies and classifies the cleanliness risk points in the whole processing process, ensuring that each step of the parts from pretreatment, intermediate treatment to packaging is effectively cleaned. In the pretreatment stage, through accurate polishing and oil stain particle cleaning, burrs and oil stains are completely removed, laying a good foundation for subsequent processing. In the intermediate treatment stage, ultrasonic cleaning and finishing are used to further remove foreign matter and fiber residues, improving the surface quality of the parts. Before packaging, demagnetization, residual magnetism inspection and three-step cleaning method are used to completely remove magnetic substances and residual particles, ensuring that the cleanliness level of the parts reaches or exceeds the aviation standard. In addition, the gas phase packaging method is used to effectively prevent the contamination of the parts during storage and transportation. During the whole process, special attention is paid to the protection of the parts, such as the use of part box protectors to avoid bumps, and the use of fine filtration and cleaning steps to reduce the damage to the parts. Under the joint action of these measures, not only the cleanliness and quality of the aviation gear parts are improved, but also the production efficiency is improved and the cost is reduced, which provides strong support for the development of aviation industry.

[0151] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing specific embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0152] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, within the technical range disclosed by the present application, according to the technical solution and disclosed conception of the present application, makes equivalent replacement or change, should be covered within the protection scope of the present application.

[0153] Further detailed description of the disclosure cannot be regarded as limiting the specific embodiments of the present application to the disclosure, and for ordinary skilled persons in the art of the present application, without departing from the concept of the present application, a number of simple deductions or replacements should be regarded as belonging to the present application, which is determined by the submitted claims.

Claims

1. A method for controlling the cleanliness of aircraft gear components, characterized in that, include: Identify the cleanliness risks associated with the entire manufacturing process of aerospace gear components; All cleanliness risk points are divided into pre-treatment risk points, intermediate treatment risk points, and pre-packaging risk points; To address the pretreatment risks, grinding and oil particle cleaning were used sequentially to treat the aerospace gear parts. To address intermediate processing risks, ultrasonic cleaning and finishing processes are used sequentially for aerospace gear components. During the handling of aerospace gear components, parts boxes are used to protect them. To address the risks before packaging, the aircraft gear parts were treated sequentially using a three-step cleaning method: demagnetization, residual magnetism inspection, and cleaning. The cleanliness level of the aircraft gear parts was then assessed after cleaning. To address the pretreatment risks, the specific steps for treating aerospace gear components using grinding and oil particle cleaning methods are as follows: Grinding wheels and files are used to remove burrs from the teeth of aerospace gear parts along the tooth tip circle and end face, grinding the tooth profile to R0.2max, and grinding the remaining parts to R0.3max; at the same time, a felt wheel polishing method is added to remove residual burrs at the tooth profile transition. After polishing, a stereomicroscope is used to inspect the aerospace gear parts for residual burrs; The oil stain cleaning method employs a process of soaking, rinsing, and compressed air drying to remove oil stains and metal particles adhering to the surface of aerospace gear parts before heat treatment, and to clean aerospace gear parts before and after magnetic detection to remove residual liquid. After cleaning with oil particles, the surface of the aircraft gear parts is visually inspected. To address the risks associated with intermediate processing, the specific steps for treating aerospace gear components using ultrasonic cleaning and finishing processes are as follows: The process of soaking and rinsing, single-tank ultrasonic cleaning, and compressed air drying is used to remove foreign matter and fiber residue from aerospace gear parts before they enter the processing and testing. After the removal of foreign matter and fiber residue is completed, the surface of aerospace gear parts is visually inspected for foreign matter and fiber residue. The specific process of the single-tank ultrasonic cleaning includes: Mix the water-based cleaning agent and deionized water and place them in a single-tank ultrasonic cleaner; Set the single-tank ultrasonic cleaner to a cleaning frequency of 40-45 kHz, a cleaning time of 3-5 minutes, and a heating temperature of 40-55°C. Aircraft gear components are placed in a single-tank ultrasonic cleaner to complete the single-tank ultrasonic cleaning process. After precision machining of aerospace gear parts, a finishing process is used to finish the parts in order to reduce burrs and metal shavings residue. To address the risks before packaging, the following steps were taken to treat aerospace gear components: demagnetization, residual magnetism inspection, and a three-step cleaning method. The specific steps for assessing the cleanliness level of the aerospace gear components after cleaning are as follows: Demagnetize aircraft gear components, and after demagnetization, use a magnetometer to check for residual magnetism. The standard for passing the residual magnetism check is: the residual magnetism value is less than or equal to 3GS. A three-step cleaning method is used to process aerospace gear components. The specific steps are as follows: After residual magnetism inspection, aerospace gear components are subjected to pre-cleaning, through-process cleaning, and combined cleaning in sequence; the ultrasonic frequencies corresponding to pre-cleaning, through-process cleaning, and combined cleaning are decreased in sequence to remove residual particles of different sizes; Cleanliness level testing is performed on the cleaned aircraft gear parts to achieve a cleanliness level assessment.

2. The method for controlling the cleanliness of aerospace gear components according to claim 1, characterized in that, The cleanliness risk points include the following categories: The first category is aircraft gear parts. During the processing of aircraft gear parts, burrs are generated by turning, grinding, hobbing and grinding. If the burrs are not completely removed, there is a risk of burr residue. The second category consists of aerospace gear parts with particulate matter adhering to their surface before heat treatment, and the tiny particulate matter being coated during the heat treatment process, which poses a risk of subsequent detachment. Category 3: During magnetic testing, there is a risk of foreign matter being introduced into the magnetic testing fluid. Category 4: Before processing and inspection, there is a risk of foreign matter and fiber residue on aerospace gear parts; The fifth category, aircraft gear parts, poses a risk of environmental pollution during their turnover and packaging. Category 6: Residual magnetism exists during the processing of aircraft gear parts, posing a risk of residual metal dust adhesion. Category 7: Improperly arranged cleaning process, which poses a risk of incomplete cleaning.

3. The method for controlling the cleanliness of aerospace gear components according to claim 2, characterized in that, Cleanliness risks also include: Category 8: During the packaging process, there may be issues with the impact or damage to aircraft gear components.

4. The method for controlling the cleanliness of aerospace gear components according to claim 3, characterized in that, Vapor phase packaging is used to package aerospace gear parts after the cleanliness level assessment is completed.

5. The method for controlling the cleanliness of aerospace gear components according to claim 1, characterized in that, The specific steps for pre-cleaning, through-flow cleaning, and combined cleaning of aerospace gear components after residual magnetism inspection are as follows: A single-slot ultrasonic wave with an ultrasonic frequency of 40–45 kHz was used to pre-clean aerospace gear parts after residual magnetism inspection. A multi-slot ultrasonic cleaner with an ultrasonic frequency of 28-35KHz is used to perform through-type cleaning of aerospace gear components. A composite cleaning method is used for aerospace gear parts, employing vacuum low-frequency ultrasonic rough cleaning (20-25 kHz), vacuum low-frequency ultrasonic fine cleaning, and high-vacuum drying.

6. The method for controlling the cleanliness of aerospace gear components according to claim 5, characterized in that, Multi-slot ultrasonic filters employ six-slot ultrasonic technology, with filtration accuracy ranging from 50µm to 5µm.

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