Design And Implementation Of The Airtight Detection System Based On PLC Technology

Due to the rapid progress of science and technology and the rapid development of production technology in modern industrial, people put forward higher requirements for product detection technology. In many of the detection method, the airtight detection method is one of them. It is used to detect airtight container for leaks and plays a vital role to ensure product quality. In many industries at present, such as medical, food, automotive, aerospace, semiconductor processing, gas pipelines and other fields, air tightness detection occupies an important position. For a product with characteristics of airtight container, in use process, if a sudden container leakage happens and leakage amount is larger, more than a certain range, the first product will definitely get a certain degree of influence, the performance of the second, is also likely to happen more serious consequences. In recent years, with the development of gas tightness detection technology at home and abroad gathered pace, now also in chemical industry production gradually incline to the whole automation, generally air tightness detection method has been unable to meet the testing requirements. Consequently, automatic air tightness detection experimental system gradually into the line of sight of people, and become more mature in the field of air tightness test.Based on the above situation, this paper introduces a kind of airtight hydraulic automatic detection system based on PLC control. The system uses high precision pressure transducer to detect airtight performance of airtight container. It also uses PLC control and man-machine interface touch screen to display real-time detection and test results. And it uses air compressor and water pump motor to add the pressure in the closed container properly from the two aspects of pneumatic pressure and hydraulic pressure. PLC is used to control the pressure relief valve opening and closing to overcome the disadvantages of the traditional method easily affected by subjective factors. It realizes the automatic air tightness detection process which can be developed and is practical.This paper firstly described the research background, current situation at home and abroad and the significance of the research. The common methods of tightness test are introduced and compared. It also determined the design scheme of the system and the overall structure diagram. And the hardware circuit and software system is analyzed in the paper. In the hardware design, this article introduced the system overall framework, the reasonable selection of each module, the pressure signal acquisition and processing circuit. In the software design, this article introduces the selection of PLC, distribution of input and output and design ideas. The flow chart and the corresponding control program are given. The paper gives the design of configuration software of touch screen and a corresponding program. After the whole detection system is designed and installed, we do the actual testing of the whole system. At the same time, in order to improve the detection accuracy, we also analyze how to choose appropriate parameters. Finally, this paper concludes the detection results through testing examples and gives the performance index of the system.