Simulation And Design Of Differential Pressure Air Tightness Test System For Complex Cavity Part

Sealing performance is a key indicator of sealing devices in the industry, and airtightness testing is one of the most critical tools to ensure the sealing performance.Owing to the advantages of high detection accuracy and realizing quantitativeanalysis, differential pressure tightness test method is gradually replacing thetraditional water detection method, which relied primarily on workers’ subjectivejudgment. With the development of scientific and technological level, differentialpressure tightness test method becomes the new mainstream of air tightness testingindustry.This subject involves the study of differential pressure air tightness test forcomplex cavity parts, such as the general and special requirements and factorsaffecting the measurement accuracy. By use of building simulation model of dynamicsystem for detecting gas, it will provide support for optimizing the existing theory ofdifferential pressure air tightness test system.During the air tightness testing process of complex cavity parts, it will realizecollection and transport of real-time data, because of adopting advanced sensortechnology and data communications technology. Meanwhile, in use of closed ringcontrol principle, detection process will automatically control and regulate to form astandard detection environment in minimum time. And it fast and accuratelyaccomplishes parameter collection in order to meet the need of production line cycletime. In addition, it uses system statistics, drawing curve and analysis of report to helprelevant personnel make decision and judgment. As a result, the supervisors willacqire quality information of each detection part in time, and able to grasp and controloverall quality and technology of enterprise production. Therefore, study on thissubject is of great both theoretical value and actual value.This paper introduces the principle of the airtight detection system based ondifferential pressure, establishes the mathematical model of the system, and presentsthe simulation based on the model with Simulink. Though the simulation results of thedetecting process, it clearly shows that the changes of the pressure and thetemperature of the inner airtight containers and those differences of measuredparameters have influence on differential pressure. Finally, the amount of leakageformula is derived from the existing formulas. And then, taking the engine exhaust manifold as an application case of Complexcavity, I will develop a set of integrated automatic test system for engine exhaustmanifold, which has the function of automatic positioning and clamping and amistake-proof feature. Meanwhile, it can automatically implement air tightness testingof engine exhaust manifold and integration management of detection information.Furthermore, it can be far higher than existing manually detection system in aspects ofdetection precision, automation degree, reliability, security and the productionefficiency. Finally, the automatic test system is also able to meet user demand, savehuman labor, reduce cost and let enterprise exhaust manifold production make afurther step than the previous. Additionally, the automatic test system of air tightnesshas a certain value of generalization.