The Research Of Air Leak Detector Based On Single Chip Microcomputer

With the development of modern manufacture technique, the higher requirement of detecting method is put forward. Leakproofness detecting, as a method of detection, play a more and more important role in quality assurance of products. Especially in automobile industry, the leakproofness of cylinder influences the performance of auto car directly. For the development of detecting techniques, the research of leakage detector makes the detecting techniques in widely application. The traditional method of leakage detecting is inflexible, tending to cause mistakes, going against data storage and analysis. Because the leakage detecting by air pressure decay has some advantages such as simple principle, cheap, convenience and involution, it becomes more and more popular in the field of leakproofness detected.An air leak detector based on the technique of dry leakage detecting (air pressure decay) and 89C58 single chip microcomputer is designed in this paper. High accurate A/D is applied to detect pressure and temperature signal, LCD is used to display the pressure data, the communication interface is also provided to store and analyze data conveniently. The disadvantage of traditional leakage detecting method is conquered and the detecting automation is realized.First of all, the background and research actuality are advanced. Several kinds of leakproofness detecting methods are compared. The entire model and framework of the leakage detector are designed. Secondly, the hardware circuit and software program are analyzed separately according to the modularized design thought. The hardware circuits include: collection circuit of pressure signal, collection circuit of temperature signal, keyboard and LCD circuit, drive circuit of electromagnetism valve, power supply circuit and control circuit; the software functions include: main function, collection function of keyboard value, read-write function of LCD standard interface, function of virtual IIC bus, function of overcoming zero-point excursion and function of customized communication protocol. Meanwhile, the flow charts and design thoughts of the function modules are presented. At last, the precision of the system is gained by analyzing the experimental results. The characteristics and disadvantages are concluded and some valuable references to the researchers are given.