ディーゼルエンジン噴射系の圧力脈動波発生要因の解析

抄録

Today, there are strict environmental regulations for automobiles, including noise control. Although, there are numerous studies focused on diesel engine noise, research on noise generated by fuel injection has been relatively limited. Therefore, it was promoted the scope of this study. In diesel engines, common rail system has been introduced to increase injection pressure to improve combustion. Currently injection pressure of 100 MPa ~ 200 MPa is available, resulting in higher impact and oscillation of fuel line pressure during injection. Therefore, the noise from injection system may be also enlarged. Hence this study aims to reveal mechanisms of noise generated from pressure fluctuations by diesel engine injection system. Firstly, a mathematical model imitating fuel pressure fluctuations on an injector and a fuel-delivery pipe was constructed. Secondly, the noise generated from injection system during an engine running was recorded and used to spectrum analysis. By comparing the numerical calculations from the model with the noise characteristics, the mechanisms of pressure pulsation generation were analyzed.