The postal connector is sufficient for the aerospace system engineer, and the supporting components from the system sub-system cabinet combination printed board to the individual towels replaced by each division are 1 yuan. With each position, buckle 1 is responsible for the power transmission and signal control and transmission of the control system. The fire effect of any electrical connector will lead to the failure of the entire dirty sky system. This aspect has occurred in the history of domestic and foreign aerial rulers. The 1 pride is very profound. The author once published the failure analysis of the electrical connector for aerospace in 1996. It summarizes and analyzes the common diseases and frequently-occurring diseases of the aerospace electric conjugator. Through the recent inspection practice and study inspection, especially the quality of the 4 tubes that carry the defects , The pen thinks. Accurate analysis of the failure mode and failure mechanism of aviation and human electrical connectors is of course important, but it is often after a painful price has been paid; more importantly, it is necessary to implement the principle of double zeroing in aerospace quality management, actively carry out The island set obituaries can be controlled under art production. Division 7 earnestly carried out the basis of fire efficiency analysis. Investigate how to prevent failure. Occurs when the electrical connectors of different models developed and produced are invalid. The political and economic losses caused to the country and enterprises are not the same. The closer to the final use stage, the more losses and costs are owed to the professional production plant as an aerospace electrical connector. Every effort must be made to design processes and inspections. The analyzability of improving products in other aspects is the basis. Prevention is self-conscious. In a sense, preventing failure is more important than analyzing failure. It has a more realistic meaning to ensure the quality and reliability of the aerospace electrical connector. 2 The fatal failure of the aerospace electrical connector is a device that provides fast connection and disconnection of wire and cable ends. In the future, the contact part of the conduction must be conductive, and the contact must be reliable; the insulation part that should not be connected must be insulated and reliable. The fire efficiency model of the aerospace electrical connector is very customer-friendly. According to pen test practice. It summarizes the following fatal failure modes, especially the fatal under-efficiency is the hidden sharp effect of the aviation electrical connector, must take preventive measures to prevent, 2.1 poor contact is the heart of the electrical connector. It is also the conductive part of the electrical connector, which transmits the voltage or signal from the cable or wire connected to the tail of the connector to the contact piece of the matching connector pair 1.3. Therefore, the contact piece must have an excellent structure, stable and reliable contact retention The selection of force and good materials is wrong, the processing size is too poor, the dough is raw sugar, and the date of the hot harvest is. 2,027 Use bad environment and less evil; improper use of loose work, Tai will cause poor contact in the contact parts and termination parts of the contact case. Case 1 is used for the small-sized plug of the carrier cable network of the carrier carrier During the continuity check, it was found that the other hole had a low separation force and poor contact. In order to determine that the shooting range is already in place, the (8) batch of plugs in the ready-to-launch state are in reliable contact with the apricot. Therefore, at the base site, a single-hole separation force check must be carried out for each insertion one by one with standard pins and weights. Case 2 is used for a wall-penetrating Mygui, a carrier of a certain type of launch vehicle. It is found at the base that some contacts are poorly connected, and there is a broken circuit. When inserting, the inner transfer pin has white silicone rubber climbing to the contact part of the jack and the pin, and the separation force of some transfer pins is also unqualified. Therefore, it is believed that there is a 1+ defect that is not recognized by the luxury of the production structure, and the product design scheme must be improved to improve the design reliability of the product. Case 3 A small rectangular socket with 4 single-ended wire crimps was fed, the user found that the 28-point pin wire was not conducting during the continuity test, and the 28-point 4-wire horse and 10-point cable were used to form a path. After analysis, it was caused by the false vomiting at 28 o'clock; the assembly and threading process of the 28 o'clock conductor and the 10 o'clock crimped conductor. 2.2 The role of the poorly insulated relay is to keep the contact pieces arranged in a correct position, and to insulate the contact pieces and the housing between the contact pieces and the contact pieces. Therefore, the insulation parts must have good quality. It is widely used along the old door + bar Huatun connection. Some people have a milk training ⑴ to Huaru, which puts more stringent requirements on the accuracy of insulating material injection molds and molding processes. Claim. Excess metal present on or inside the insulator. 1 angstrom. Wetting and other pollutions, fluxes of ergonomic materials and the adsorption of harmful gas and surface water film to form ionic conductive channels, and aging of moisture-absorbent and mold insulation materials will cause short-circuit leakage shock and poor insulation resistance, color line + Good phenomenon. Vibration test of glass sintered sealed socket, the number is unstable, there is a short circuit between the pin and the shell at a certain point of the socket. Through observation and analysis, it was found that the gold-plated layer of the socket began to corrode partially, and the gold-plated layer was peeled off at the junction of the sintering of the single pin glass and the shell. Sticking together, case 2 The round socket produced by a certain factory requires a voltage of 1300 not to break down, and the insulation resistance requirement is greater than 1000. Use extensive obliteration screening. It is found that the insulation resistance between the 1st and 2nd pins is not Pass, insulation resistance is only 20 withstand voltage 700 breakdown. Anatomical analysis revealed that there were carbon black-like breakdown traces between the upper and lower insulator cores. After joint analysis with the production plant. It is considered that the potting glue used by the factory's glued insulators on the upper and lower mounting plates is unclean. Individual 2.3. The poorly fixed shell is the electrical connector. The connector shell is usually extended. The contact parts provide accurate centering and protection. It also saves the power of the positioning device and the locking device of the inkstone. It is bad, and it may affect the reliability of the contact and cause a momentary power failure. It will lead to the disassembly of the connector. , Undo the edge, the connector is in a closed state. Due to the material design process and other reasons, the structure is not reliable and the abnormal separation between the plug and the socket between the insulator and the housing or between the pin and the jack will result, which will cause Control system power transmission interruption signal Serious consequences of control interruption 3. Unreliable design structure, incorrect material selection, improper selection of forming process, poor quality of machining heat treatment mold assembly riveting, etc., deformation of elastic parts, leakage of riveting nails, inadequate assembly, etc. Will cause poor fixation. Case 1 A round crimped plug socket used in a key project has undergone severe disassembly accidents when the plug housing and insulator are separated from the outer connecting ring during the single-unit joint test. After forensic analysis, it is believed that due to the insufficient depth of the positioning groove in the connecting ring, the clamping ring is unscrewed under the action of external torque or other rotating forces, resulting in the failure of the plug disassembly. After the improvement of the size of the knot, this case says that the size accuracy of the 7 slot must be calculated after a large number of tests. In order to get the choice of the station, the small round plug seat produced by a factory found that the plug disintegrated during the basic test. After forensic analysis, it was found that the snap ring in the plug was not in place and was not fully pressed into position. , Resulting in the separation of the case and the insulator from the connection ring on the plug connection with the screw connection when the force is applied. Case 3: The 1204ug socket of the power supply system of a key project in a dead body was found. After returning to the field test, the matching short circuit was found. The plug is crooked. Elephant. Upon inspection, it was discovered that there were one remaining nail stuck. The analysis believes that the reason for the connection of the olive is that the socket shell is fitted with nails, and the two 1 unriveted side edges of the real center Ting 2.4 poor sealing The sealed electrical connector for aerospace has two forms of resin sealing and glass sintering sealing. Resin sealed sockets are commonly used for rough leak detection by air pressure method, while glass sintered sealed sockets must be accurately inspected with a 4 mass spectrometer for leak detection, by the quality of tire potting and glass sintering. 1 Art quality! 1 Poor insertion of the contactor 1 and other reasons may cause the housing and the insulator or the insulator and the contact to cause poor seal failure. Case 1 A certain type of circular socket shell and insulator were sealed with a claw knife adhesive to cure and seal the tightness, and an air leak was found. The analysis believes that it is due to incomplete curing of the adhesive, and a large hole is received after the force curing. The technical conditions of the Ke-shaped sealing plug product produced by a factory in Longtu stipulate that the leakage rate should not be greater than 105.18. The part of the leaking ruler is unqualified. The reason for the inspection is that the production plant was temporarily replaced by the alcohol bubble method due to the failure of the helium mass spectrometer. The unqualified product was shipped from the factory because the test method did not meet the standards. In addition, the shell is plated 2. The skin is corroded and scratched, the insulator has burr cracks, and the contact parts are rough. Deformation and other Yuan Na earn secret benefits, Pian Zhongzhong ultra-poor processing quality and poor total separation force, and other reasons for poor interchangeability are also common diseases of aerospace electrical connectors. Both of these failures can be found and eliminated in time during inspection and use. 3 Measures to prevent failure 3.1 Cultivate the quality culture of enterprises To prevent failure, you must advocate a human-centered management. Product quality depends on the quality of people, and quality is created by people. therefore. The core starting point of constructing and training and qualitative culture is people. It is not terrible to find failure, what is terrible is not to stand at the height of safeguarding the overall interests of the enterprise and seriously enter the hall to divide the prayers, turn the bad guys into good things, and take corrective and preventive measures in time; but to cover up for the immediate interests of individuals or departments And evade the practice of spear. For example, if a factory has 18 batches of aluminum casing surface peelings continuously in just a few factories, it is clearly a question of process quality, but it is designed and signed by the supervisor on the unqualified trial form. The reasons and preventive measures on the trial form Both columns are blank. During the National Quality Month, the factory held an internal waste exhibition to display a large number of various waste products, and did not analyze the causes and responsibilities. The author believes that strengthening quality consciousness and treating Xianlun should strengthen the quality awareness of enterprise leaders. The quality consciousness of the enterprise leader is the decisive factor for the survival and development of the enterprise. Only when the quality awareness of the leader is enhanced can the quality development strategy be implemented, the comprehensive quality of the enterprise can be effectively improved, and the market competitiveness can be developed and produced. The product. Quality values ​​not only affect individual behavior, but also group behavior and overall enterprise behavior, which in turn affects the enterprise's profitability image and reputation. 3.2 Carry out zero-defect quality tube 5 The standard of quality loan bamboo burying is completely zero-defect. Ask every time to get things right. The best way to improve quality is to prevent in advance, and not to inspect afterwards. Now some factories are pursuing the progress of cattle production. After finding that the product has failed, they often do not investigate the production department. Where the product is returned to the factory is always considered by the quality inspection department. They eloquently defended themselves that the self-ic leader did not pay attention to the quality control of the production process, but focused on the final inspection of the finished product. For example, although a factory finally established a special inspection line for finished product inspection sampling and outbound inspection, it still repeatedly suffered from fatal failures that seriously affected the reputation of the company, such as poor contact. To carry out zero-defect quality management, every employee is required to be clear and do things clearly, and every seven people are cleaned up and controlled. Everything the enterprise sentence people do is managed. To achieve control without missing items, all matters have a look for indicators to compare and correct deviations, to achieve the purpose of controlling things in the development process of things, and to ensure that things develop towards predetermined goals. If a person is in a position, what should he do to himself, how many standards should he do, and what results will be countless in his mind, it will be difficult to achieve zero defects. 3.3 Internal quality audit The internal quality audit can provide enterprises with the objective of reducing and eliminating fire, which is the objective evidence for preventing fire effects. It reveals some weak links that have not yet reached the requirements of the standard, and serves as the basis for the rectification of the enterprise to improve the quality system to reach the model standard. Through internal audit, systematic analysis of relevant information about unqualified failures is taken as the main basis for enterprises to take the decision to prevent failures. Since the internal audit is a sampling process, the audit and inspection can only be done. It is impossible to track the entire process at a certain time. It is necessary for each department to analyze the causes of the failures detected by the department and take preventive measures to prevent the recurrence of similar failures. Moreover, the unqualified Qiong tears found in other departments were also self-examined and self-corrected. 3.4 Implementation of the reliability of aerospace electrical connectors, a long-term engineering plan A professional manufacturer of aerospace electrical connectors should prepare and implement a hanger-tuning edge, and a surplus of labor. 1. The friend case must be actively sweated, and the Jiajiatun connector can be Bamboo is the best. Design juice experiment and statistical work. Through the 0 test, strive to give the quantitative reliability index of the connector. The reliability of the aerospace electrical connector. The electrical connector standard of the aviation system engineering index. To this end, the production plant and users must cooperate closely. First of all, the production plant should cultivate and produce a failure analysis with rich practical experience; the team can accurately record and analyze the various design processes and inspection quality that appear in the process of low production, and take timely measures to prevent and corrective measures. The user should respond Examine the quality and reliability of the entire use process such as assembly and testing, including the time and place environmental failure phenomena and failed parts, etc., make detailed and accurate records and feedback to the production plant. In order to enable the production plant to analyze the fire effect of the recognition lamp and find out the reason. Thereby taking effective measures for cranial fire prevention. Timely reorganization of Juice 1 art files. It is the most effective way to increase the reliability of aerospace electrical connectors by improving the design process and preventing failures due to the defects exposed during product use. 3.5 Pay attention to and strengthen the technological transformation of process equipment and testing equipment. Through the recent analysis of many failure cases, our reflection is enough to meet the growing variety and quality requirements of electrical connectors in the aviation industry. We must introduce many advanced connector production, art equipment and loose testing equipment from inside and outside to provide service for the production of dirty electrical connectors. For example, glue filling is now manually operated with syringes in many factories. It is difficult to control the amount and uniformity of the glue filling. If it is infiltrated into the interface of the contact parts after excessive local pressure, it is easy to cause poor contact. That. Ding Xu can complete the operation with automatic dispensers introduced by many manufacturers in front of the mouth. It can be used for plane and three-dimensional operation. It can be programmed for dots, lines, surfaces, irregular glue time and walking speed. It can be used for any high and low concentration liquids. It can also be used for direct-view programming. The operation interface is simple and easy to use. Another example is that the total separation force of many factories is measured by bullets. The separation force of a single hole is measured with a standard pin and a weight, the pull-out force of the 01 connecting wire is measured with a hanging weight, and the mechanical life is manually inserted and removed; and these inspection items can be completed with a fully automatic insertion force testing machine The pause time of the device's insertion speed and the fixture in drawing the insertion and removal displacement curve, so it is possible to carry out high-precision single-hole separation force total separation force mechanical life and crimped wire pull-off force tests. The author believes that there are many high-tech and mature process detection methods in the production of civil connectors and cable assemblies. Through learning and borrowing, it can be used in the process equipment and testing equipment of the aerospace electrical connector production plant In order to ensure the quality and reliability of aerospace electrical connectors, and prevent the occurrence of fatal failures, it is recommended to study and formulate phases according to product technical conditions. The screening techniques are well-organized and open, and the following targeted reliability tests to prevent failures. 4.1 Prevent poor contact 4.1.1 Continuity testing At present, there is no such item in the product technical condition settlement test, and users generally need to conduct continuity testing after installation. But some inspection methods are quite primitive. The buzzer is very delicate, tedious, and easy to fatigue, and it also needs to be compared with the paper wire core wire anvil to cause missed detection and error detection. Here, let the Yiyi connector production factory match some adapter connectors for key bamboo. For example, a through-walled plug-in socket with internal and external plugs and a connector assembly with wires and cables should be increased by 100 for point-by-point detection. The continuity detection of the net or wire harness components produced by Necco in Japan. The machine is connected to a computer, and can quickly determine whether each contact has a short circuit or a miswiring, etc. = 1 continuity meter is suitable for 128-point 64-way single-end wire Cambodian detection. The biggest advantage of this instrument is that it can prevent missed inspection. Manually point-by-point continuity detection, missing missing points are often difficult to detect. 1 Coughing the instrument means that as long as the point is missed, no qualified sound can be made 4.1.2 Instantaneous break detection Many aerospace electrical connectors are used in dynamic vibration environments. The experiment proves that only the static contact resistance is tested to be qualified. Feng can not guarantee that the use of contact in a dynamic environment is often electric shock, and the instantaneous device 1 still has a momentary power outage during simulated environmental tests such as vibration shock centrifugation. Therefore, for some high reliability, 100 dynamic vibration test is required to evaluate the contact reliability. Recently, Necco has launched a portable small 71 and 10 parallel independent circuits for use with the 14-way instrument. The instantaneous power-off time of the monitor can be set to 0.199.9 according to the technical conditions of the product. The vibration table can simulate the generation of less than 1001. Low frequency vibration. At present, this set of equipment has been successfully applied to the reliability inspection of civil wiring harness used in many vibration environments. The author believes that it can also be used for dynamic contact reliability testing of aerospace electrical connectors. 413 Flat hole separation force detection The hole separation force refers to the separation force of the contact in the inserted state from static 1 to motion. The separation force of the open hole in the experiment is too small, which may cause the signal to be momentarily interrupted when subjected to vibration and shock loading. It is more effective to measure the contact reliability by measuring the separation force of a single hole than to measure the contact resistance. The inspection found that the jack with a single hole with excessively poor separating force often still measures the contact resistance. To this end, it is recommended that in addition to the development of a new generation of flexible plug-in contact stable and reliable contacts, the manufacturer should also adopt an automatic insertion force testing machine for the key electrical connectors cited in the key models for the point-by-point order of the finished products. Hole separation force check to prevent signal interruption caused by loosening of individual jacks = 4.2 Prevention of poor insulation 4.2.1 Insulation material looseness The quality of raw materials has a great influence on the insulation performance of the insulator. Therefore, each batch of thermosetting plastic powder or thermoplastic pitch Bian mold, according to the current injection process to test a sample of insulators, to determine whether the insulation performance meets the requirements of the product technical requirements, 4.2.2 Insulation insulation resistance test is currently partially produced The factory process stipulates that the electrical properties are tested after being assembled into finished products. As a result, the insulation resistance of the insulator itself is unqualified, so the entire batch of finished products has to be scrapped. A reasonable process should be a process screening of 100 in the state of insulator parts to ensure that the electrical performance is qualified. At present, the electrical performance testers used by many domestic connector manufacturers are single-parameter, such as insulation resistance tester and contact resistance tester. Need to plug in and swap out the instrument multiple times and change 23 test fixtures many times, the operation is relatively complicated. 1 Japanese 1 person, try out ⒚ out of 18 companies, etc. to launch the Duo Quanneng automatic performance tester, the internal logic adopts 1 dynamic logic The digital circuit is called, and the second insertion can quickly and accurately complete the automatic detection of the conduction insulation voltage and instantaneous interruption; use the computer menu to set the parameters such as the test voltage test time leakage current insulation resistance threshold; the instrument has a self-test function To determine whether the instrument is normal before the test; it can also compare the tested connector into a harness and the memory sample information of the memory to judge whether it is qualified; it can automatically print out the test results and query records through the computer. 4.3 Preventing poor fixing 4.3.1 Interchangeability check Interchangeability check is a dynamic check, which requires that plugs and sockets of the same series can be mated with each other. It was found that there is no reason why the size of the 1st body insulator contacts and rubber pads are out of tolerance, missing parts or inadequate assembly, etc., which can not be inserted and positioned and locked, and even cause disassembly under the action of rotating force. Another function of the interchangeability check is to find out whether there is any metal excess that affects the insulation performance through the plug connection of the thread bayonet and the like. Therefore, it is recommended that the electrical connectors of some important uses should be inspected by the project to avoid this major failure caused when the base is in the state of the base. 4.3.2 Torque Checking Torque checking is a kind of assessment of the reliability of the electrical connector structure. Effective inspection method. For example, the US Army Standard Factory 39012 standard stipulates that 81 RF plugs use a special constant force wrench for torque resistance inspection. The torque requirement is 0.791.131. 90 RF plugs produced by a certain factory are produced. The ring was disassembled without being fully inserted into the positioning groove of the screw sleeve. After the accident, according to the standard, a torque wrench was used to check the torque resistance one by one, and it was found that one of the same failure mode was disassembled and inserted. At present, most of the technical conditions of aerospace electrical connectors do not have a torque inspection project. Therefore, we have researched and developed a method for aerospace electrical connection No. 1 factory 1 pine 1 inspection, Ji, Zhuang, an urgent task in front of us. 4.3.3 General test of crimping wires The environment-resistant and fast connection of the 46-type ships with crimped wires can not be delivered in place, or cannot be locked after being delivered, and the contact is unreliable. The reason for the analysis is that there are burrs or excess glue at the location of the tooth sleeve of the individual mounting holes. A certain factory has installed the last few mounting holes of a plug socket. After finding the defect, the crimped wires of other holes that have been installed must be removed and the plug socket should be replaced again. In addition, due to improper selection of the wire diameter of the wire and the crimping aperture, or due to an error in the operation of the crimping technique, it may also cause an accident in which the crimping end is not secure. For this reason, it is recommended that the manufacturer conduct a general test of the installation holes of each plug seat delivered before the finished product is shipped, that is, use the loading and unloading tool to simulate the wire with the pin or jack crimped in place, and check whether it is possible Lock 4. Check the pull-out force of the crimped wire one by one according to the product technical conditions. 4.4 Prevention of poor sealing For electrical connectors with tightness requirements, strict inspections must be carried out in accordance with the requirements of the standards. The inspection rate of the seals is one by one. The safety of the electrical connectors with a sealing requirement such as 1 ship ’s satellites is particularly safe, especially to ensure aerospace. The test methods and test conditions stipulated in the life assurance system of personnel shall be inspected, and the test conditions and methods shall not be changed without authorization. Before leak detection, use standard leak holes to calibrate the instrument into the hall to ensure the accuracy and reliability of the leak detection value. 5 Conclusion There is no guarantee for a reliable electric shunt. No, the aerospace systems engineering. Failure and reliability are two sides of a contradictory body that are opposite and interrelated. Through the beneficial screening of the Tuner connector, we can find a kind of sharp correction and failure mechanism, which can lead to a lot of lessons and eliminate various hidden dangers. art. It is also an important basis for testing and providing scientific support and it is sufficient for repairing and formulating the technical conditions of electrical connectors for aviation. Finding measures to prevent failures, and achieving the transformation from failures to possible; is the ultimate goal of fire efficiency analysis. Preventing failure is a cross-cutting science involving many disciplines such as mechatronic materials chemistry. The electrical connectors involved are not made of isolated materials. It involves Yuli temperature corrosion of dust insulation electromagnetics, disturbance of the influence of high-frequency distribution parameters of small structures, and so on. Ignore any details. The possible losses will not be estimated, and its adverse effects will continue for a long time. Although the failure of electrical connectors occupies a large proportion in the failure statistics of the entire aerial ruler's electrical components, we still have a large gap in its requirements. The United States before launching the spacecraft to the moon. Invited to collect electricity contacts; 1 company conducted simulation tests on 10,000 contacts of the spacecraft, with a total cost of 100 million US dollars to ensure foolproof, so that peers in the world admired its rigorous scientific attitude. The investment in electrical contact research for electrical connectors is still inadequate. The purpose of the author's writing is to expect leaders and colleagues to attach great importance to and define research in this area, and strive for a more reliable growth test, especially to conduct reliability tests to simulate the special use environment of aerospace, study and analyze the failure mechanism, and form An experimental system that can meet the needs of the development of the aerospace industry in order to take active improvement and preventive measures on the basis of a large number of experiments to improve the quality and reliability of the aerospace connector, Yang Fenwei. Failure analysis of aerospace electrical connectors. Electromechanical components, professional information network for connectors, 199 Yang Fenwei. Failure analysis of the disassembly of aerospace electrical connectors 4. Shanghai Yang Fenwei. Research on contact reliability of aerospace electrical connectors. The subject of electromechanical contact studies the reliable connection of electronics. Modern connection technology, 2001.10. Lu Xianfeng. Stamping process die science. Beijing Machinery Industry Press tt, Li Shuoben. Stamping Technology Beijing Machinery Industry Press. 3 Tu Guangqi. Analysis of Fine Blanking Deformation Process and Research on Tooth Profile Parameters of Blank Holder CAT6A UTP Keystone Jack CAT6A UTP Keystone jack NINGBO UONICORE ELECTRONICS CO., LTD , https://www.uonicore.com
May 29, 2024