Study On Manufacturing Process And Vibration Fatigue Performance Of EGR System

With the development of society, the number of applications of gasoline and diesel increased year by year, harmful gas emissions are also increasing, causing serious environmental pollution, but also caused the shortage of energy, so energy conservation has become an important problem, and regulations are more stringent. In order to reduce the emission of pollutants, the exhaust gas recirculation(EGR) technology, electronic fuel injection widely the application of technology and exhaust postprocessing technology, EGR technology is currently considered one of effective methods to reduce NO_X emissions of pollutants, many components in the EGR system, the EGR pipe is one of the structural parts, mainly used for gas transmission, absorption of vibration, reduce noise, eliminate the assembly stress. In this study, EGR in the system of EGR pipe as the research object, studies the main manufacturing process of EGR pipe and simulation technology based on optimizing the overall structure of the EGR pipe.Study on the main manufacturing process of EGR pipe, mainly divided into two parts: one of EGR bellows of different forming methods compare and choose the hydraulic expansion type processing corrugated; the second is tube bending technology research, selection of pipe bending machine, mold design bending machine bending tube and through a number of mandrel as variables, the study on the mandrel quantities for the forming of the elbow.Followed by the use of 3D software modeling, through the finite element analysis software workbench of EGR tube structure optimization design, the corrugated corrugated position and quantity as a variable, static analysis, on the different structure stress and deformation are compared, it is concluded that the number and location of the corrugated best optimal results.Finally the EGR tube modal analysis, the analysis of the natural frequency of the system, which can avoid the external excitation frequency and EGR tube itself is equal to the natural frequency and the resonance phenomenon; also study fatigue performance, change structural crest distance to change the fatigue strength, through the analysis results show that design reasonable crest spacing can improve the fatigue life.