Fault prevention and detection method of the hotte

2022-10-03
  • Detail

Terminal failure prevention and detection methods

in order to ensure the quality and reliability of the terminal and prevent the occurrence of the above fatal failures, it is recommended to study and formulate the corresponding screening technical requirements according to the technical conditions of the product, and carry out the following targeted reliability inspection to prevent failure

1. Prevention of poor contact

1) continuity detection

at present, there is no such item in the product acceptance test of general wiring terminal manufacturers, and users generally need to conduct continuity detection after installation. Therefore, it is suggested that manufacturers should increase 100% point by point conduction detection for some key models of products

2) instant break detection

some terminals are used in dynamic vibration environment. Experiments have proved that only checking whether the static contact resistance is qualified can not guarantee the reliable contact in dynamic environment. Because the connectors with qualified contact resistance still have instant power failure during vibration, impact and other simulated environmental tests, it is better to conduct dynamic vibration test on some wiring terminals with high reliability requirements to assess their contact reliability

3) single hole separation force detection

single hole separation force refers to the separation force of the contact in the inserted state from static to moving, which is used to indicate that the pin and socket are in contact. The experiment shows that the single hole separation force is too small, which may cause the signal to break instantly when subjected to vibration and impact loads. It is more effective to check the contact reliability by measuring the separation force of a single hole than by measuring the contact resistance. It is found that the contact resistance of the jack with out of tolerance single hole separation force is often still qualified. Therefore, in addition to developing a new generation of flexible plug-in contacts with stable and reliable contact, the manufacturer of products bought by chemical leather shops such as thiohydrocarbon generation should not use automatic plug-in force tester for multi-point simultaneous measurement for key models, and 100% point by point single hole separation force inspection should be carried out for the finished products to prevent signal instantaneous interruption caused by individual Jack relaxation

2. Prevention of poor insulation

1) inspection of insulating materials

the quality of raw materials has a great impact on the insulation performance of insulators. Therefore, the choice of raw material manufacturers is particularly important. We cannot blindly reduce costs and lose material quality when conditions permit Large manufacturers with good reputation should be selected And for each batch of materials, it is necessary to carefully check the batch number, material certificate and other important information Do a good job in the traceability of material use

2) insulation resistance inspection of insulator

at present, some manufacturers' processes stipulate that the electrical performance should be tested after assembling the finished products. As a result, the insulation resistance of the insulator itself is unqualified, so the whole batch of finished products must be scrapped. The reasonable process should be 100% process screening in the state of insulator parts to ensure that the electrical performance is qualified

3. Prevention of poor fixation

1) interchangeability check

interchangeability check is a dynamic check. It requires that the same series of matching plugs and sockets can be inserted and connected with each other, and it can be found whether there is any reason that the insulator, contact and other parts cannot be inserted, positioned and locked, or even disassembled under the action of rotating force due to out of tolerance dimensions, missing parts or inadequate assembly. Another function of interchangeability inspection is to find out whether there are metal residues that affect the insulation performance in time through the plug-in connection such as threads and bayonets. Therefore, 100% of the terminals for some important purposes should be inspected to avoid such major fatal failure accidents

2) torque resistance check

torque resistance check is a single station, double station, 3 station and 4 station display respectively; Synchronous rapid experiment; Automatic reset; Automatic judgment of qualified and unqualified; Multi window display of experimental data; Temperature control display; Alarm prompt is a very effective inspection method to assess the structural reliability of wiring terminals. Such as mil-l-39012 According to the standard, each batch of samples should be sampled for torque resistance inspection to find problems in time Please log in: power transmission and distribution equipment to browse more information

3) general test of crimped wires

during electrical installation, it is often found that individual core crimped wires cannot be sent in place, or cannot be locked after being sent to the position, and the contact is not reliable. The reason is that there are burrs or dirt stuck at the screw teeth of individual installation holes. In particular, the user has been electrically installed into the last few mounting holes of a plug base. After finding the defect, he has to remove the crimping wires of other installed holes one by one and replace the plug base again. In addition, due to the improper selection of wire diameter and crimping aperture, or due to the wrong operation of crimping process, it will also cause the accident of loose crimping end. For this reason, the manufacturer should carry out a through test on all the mounting holes of the samples of the delivered plugs (seats) before the finished products leave the factory, that is, use the loading and unloading tools to send the wires crimped with pins or jacks into place, and check whether they can be locked. According to the product technical regulations, we should always pay attention to the problem parts found in the use process of the experimental machine, and check the pull-out force of each crimped wire

without reliable terminals, there is no reliable system engineering. Failure and reliability are two aspects of a corresponding and interrelated contradiction. Various failure modes and failure mechanisms can be found through the reliability screening of wiring terminals, which can lead to a lot of experience and lessons and eliminate various hidden dangers, and provide a scientific basis for improving design, process, inspection and use. It is also an important basis for revising and formulating the technical conditions of wiring terminals. The ultimate goal of failure analysis is to find measures to prevent failure and realize the transformation from failure to reliability. (end)

Copyright © 2011 JIN SHI