喷油器结构参数与喷油一致性相关关系的试验研究

Correlation between Injector Structural Parameters and Fuel Injection Consistency

针对喷油器在使用过程中因结构参数变化导致喷油一致性发生变化的问题,以CRIN系列喷油器为研究对象,基于喷油器液力及机械运动过程分析,得出喷油器易损结构,运用AMESim软件构建喷油器仿真模型。采用Box-Behnken设计方法,以针阀偶件间隙、柱塞偶件间隙、针阀升程、衔铁升程为试验因子,将喷油量变化率及响应时间变化率作为影响喷油一致性的试验指标,建立各试验因子与试验指标间的回归模型,分析各试验因子对试验指标的影响规律。采用多目标优化方法得出:当柱塞偶件间隙为4.38μm、针阀偶件间隙为2.66μm、衔铁升程为0.05 mm、针阀升程为0.34 mm时,喷油量变化率、响应时间变化率分别为1.70%和2.27%,达到最佳喷油一致性。在此基础上,结合数值计算得出:当柱塞偶件间隙为3.05~5.93μm、针阀偶件间隙为1.50~3.95μm、衔铁升程为0.045~0.053 mm、针阀升程为0.33~0.38 mm时,喷油量变化率、响应时间变化率都能够满足国家标准及工程对喷油一致性的要求。

For the change of injection consistency led by structural parameter changing during the use of injector,the vulnerable structure of injector was obtained based on CRIN series injector according to the analysis of hydrodynamic and mechanical motion,and the simulation model of injector was further built by using the AMESim software.With the Box-Behnken design method,the regression equation between test factors and test indexes were established and the influence of test factor on test index was analyzed based on test factors of gap between needle valve parts,clearance between plunger matching parts,needle valve lift and armature lift and test indexes of fuel injection variation and response time variation.According to the results of multi-objective optimization,when the clearance between plunger matching parts,gap between needle valve parts,armature lift and needle valve lift was 4.38μm,2.66μm,0.05 mm and 0.34 mm respectively,the change rate of 1.70%and 2.27%for fuel injection and response time respectively was achieved,therefore the optimal injection consistency was realized.Finally,it was thought that the change rate of fuel injection and response time could meet the requirements of national standards and engineering requirements for fuel injection consistency when the above-mentioned four parameters were 3.05-5.93μm,1.50-3.95μm,0.045-0.053 mm and 0.33-0.38 mm respectively after combining with the results of numerical calculation.