Research On Diagnosis Method Using Single Order Angular Vibration On Crankshaft Of Interal Combustion Engine

The individual cylinder of misfire can be conveniently and accurately determined by the diagnosis method using single order angular vibration (DMSOAV).However,non-fault-cylinder being in "natural working condition", the effect on the phase of 0.5 order angular vibration of the crankshaft(φ_0.5) has not been taken into consideration.Moreover,the work condition(mean rotating velocity n and power P) of I.C.E varies,the law ofφ_0.5 's variety has not been analyzed.Aimming at the above issues,this paper uses simulation analysis, research by the experiment and theory analysis to solve the existent problem that diagnostic ofφ_0.5 applys in projects.Following is the main work done in this paper:Firstly,when non-fault-cylinder power is in "nature working condition" and fault-cylinder power is under changing working conditions,characteristics ofφ_0.5 corresponding to different fault-cylinders has been analyzed respectively by making use of torsional vibration calculation &analysis(TVCA) software. According to the analyzing data,following conclusions have been drawn:When single cylinder misfire,the centralized degree ofφ_0.5 is very dense,and along with the fault-cylinder power increasing,the distributing section ofφ_0.5 reduce. When the fault-cylinder power is under 85 percent,the number of the fault-cylinder can be accurately distinguished.When the fault-cylinder power is at 90 percent,veracity of estimating the number of fault-cylinder is about 90 percent,and it has worthy reference to actual project at a certain extent.Secondly,when single fault-cylinder power is entirely lose and I.C.E working condition is under changing,theφ_0.5's characteristics of rotating velocity and load,corresponding to the working conditions,has been analyzed respectively.Along with rotating velocity increasing,φ_0.5 is minishing,and the relationship of them can be described with perfect linearity equation.Along with average effective pressure(Pe) increasing,φ_0.5 is minishing,the relationship of them can be described with conic equation.The all-purpose foumula can be educed by analyzing both curvilinear characteristicses of rotating velocity and load.Lastly,relationship between the I.C.E working condition and the phase of 0.5 order angular vibration on the free end of the crankshaft(φ_0.5) has been analyzed by the theoretical research and experimental demonstration.The experimental demonstration indicates that along with rotating velocity increasing,φ_0.5 is minishing.This conclusion is consistent with simulation analysis. Moreover,the low ofφ_0.5's variety,changing with rotating velocity and original moment's phase,has been discussed.Those researches proved that DMSOAV is feasible and applicable again, offered worthy reference for the practical application of DMSOAV.