【作者】 刘军；

【导师】 盖玉先；

【作者基本信息】 哈尔滨工业大学 ， 机械工程， 2014， 硕士

【摘要】 本课题，从飞行器研制的工程实际出发，根据产品不同的状态，选取不同的气密检测方法，开展了典型导管连接组合件、储油箱导管焊缝和含铆接结构油箱的整体产品密封性检测试验研究，最终保证整体产品气密性检测一次合格。（1）用差压法替代直压法，开展了泄漏量对比检测试验。按照设计要求，管路系统气密性检测以压力变化来具体衡量，采取直压法和涂抹检漏液法进行检查。传统的直压法检测，直观性好，测试系统构成简单，根据压力变化而判断泄漏。气密性大都靠拧紧力矩和工人操作经验来保证，检测精度不高。考虑以上因素，用差压法替代直压法，开展了与设计指标要求对应的泄漏量对比检测试验。文章详细介绍了差压法的检测原理，针对非对称差压检漏系统，专门设计了样件，综合考虑温度补偿、内置基准物、合理布置测温点等手段，证明了用小容积对大容积的差压检漏是可行的。（2）用氦质谱抽真空喷吹检漏法替代气泡法，开展了泄漏量对比检测试验。按照设计要求，储油箱管路焊缝的气密性检测采用气泡法，将被检件装好堵盖、堵帽、接头等工装后，连接充气管路，向被检件充气，使其压力上升到规定的数值，内外产生压力差，气泡就从漏孔处吹起，从而显示出漏孔位置及漏率的大小。为了提高储油箱管路焊缝检测精度和检测效率，开展了氦质谱检漏方法研究。文章介绍了氦质谱检测方法的原理，针对储油箱系统焊缝气密性检测要求，开展了标准漏孔油密试验和标准漏孔气泡试验，相比常规气泡法，选用氦质谱检漏方法，能够更加有效的提高检漏精度，保证检测的可靠性。（3）介绍了整体系统气密性检测的方法。对于组合到位的系统，为了确保系统集成后气密合格，需要严格保证分系统和各个组合部件的气密性，本文以铆接结构形式的整体油箱为例，根据油箱组合过程中的不同状态，开展了铆钉油密实验，针对油箱铆接过程中工件的状态，建立了检测模型，将吸枪罩盒真空检测法应用到具体检测上，并开展了各种试验，确定了检测指标和检测精度，保证整体油箱气密性检测一次通过。同时，开展了不同氦浓度混合气体的应用试验，可以降低检测成本。针对模拟油箱典型样件，开展了系统气密性检测试验，采用直接检测法，检测过程：先向整体油箱模拟件中充入一定压力和氦浓度的混合气体，应用氦质谱吸枪法对可疑漏点处进行检测，确定其漏率。再应用氦质谱吸枪法对标准漏孔进行检测，得到已知漏率标准漏孔的反应值，由此可计算出漏源点的漏率值，根据试验结果确定合格漏率指标。更多还原

【Abstract】 This project developed from the engineering reality of aircraft manufacture, andaccording to the different states of the products, it selected different ways to take theair-tightness detection. Then it carried out a test research on the typical assemblies ofconduit connector, the weld and tightness of the oil storage tank and the tightness of thetank containing riveted structure. Finally it could ensure the tightness qualification ofthe whole product for one time.(a) Differential pressure method was substituted for direct pressure method, and aleakage comparative detection experiment was carried out. In accordance with thedesign requirements, pipeline system’s air tightness detection was specifically measuredby pressure changes, took direct pressure method and daubing liquid leak detectionmethod to detect. The conventional direct pressure method detection, with goodintuitive, simple configuration of the test system, can determine the leakage accordingto pressure changes. Air-tightness is mostly to be ensured by tightening torque andworkers operating experience, and its detection accuracy is not high. Considering theabove factors, differential pressure method was substituted for direct pressure method,and a leakage comparative detection experiment which corresponded to the designrequirements was carried out. The article introduced the detection principle ofdifferential pressure method in detail, for non-symmetrical differential pressure leakdetection system, specially designed samples, and considered the temperaturecompensation, internal standard substance, rational arrangement of measurement pointsand other means to prove that differential pressure leak detection of small volume tolarge volume is feasible.(b) Helium mass vacuum jetting leak detection method was substituted for bubblesmethod, and a leakage comparative detection experiment was carried out. In accordancewith the design requirements, bubble method was used for oil storage tank pipelineweld’s air-tightness detection, after installed blanking covers, blocking caps, the jointsand other workpieces on the seized items, connected aerating conduit, and inflated theseized items, its pressure rise was made to a predetermined value, then generated thepressure difference inside and outside, the bubble would blow up from the leak, therebythe leak position and size of the leak rate was displayed. In order to improve theaccuracy and efficiency of oil storage tank pipeline weld detection, we carried out helium mass leak detection methods investigation. This paper introduced the principleof helium mass detection method, for the requirements of oil storage tank pipelineweld’s air-tightness detection, and carried out a standard leak oil test and standard leakbubble test. Compared to the conventional bubble method, the choice of he lium massleak detection method can improve accuracy of leak detection and ensure the reliabilitymore effectively.(c) The air-tightness detection methods of the overall system was described. For asystem combined in place, in order to ensure air-tightness to be qualified afterintegrating the system, we need to strictly ensure air-tightness of sub-systems andvarious components. This article took integral fuel tank with riveted structure form as anexample, based on different states in fuel tank combining process, and carried out rivetsoiltight experiment. For the state of the workpieces in fuel tank riveting process,established a detection model, applied the suction gun cover cartridge vacuum detectionmethod to the specific detection, and carried out a variety of tests to determine thedetection indicators and detection accuracy, and ensured overall tank air-tightnessdetection once-through. Meanwhile, the application test for different concentrations ofhelium gas mixture which can reduce test costs was carried out. For a typical sample offuel tank simulation, system air-tightness detection test was carried out, using directdetection method, the detection process: first gas mixture helium with certain pressureand certain concentration of helium was filled into analog parts of the whole fuel tank,helium mass suck marksmanship was applied to detect suspicious leak source, and theleakage rate was determined. Then helium mass suck marksmanship was applied todetect standard leak, to obtain a response value of standard leak which the leak rate isknown, thus the leakage rate value of leak source can be calculated, and to determinequalified leak rate indicator based on test results.更多还原