A Service Research On Timing Choice Of Predecisional Remanufacturing For Diesel Engine Crankshaft Based On Online Monitoring

The core problem of remanufacturing is the uncertainty of the remanufacturing blank quality and quantity,which leads to the uncertainty and complexity of remanufacturing process.Predecisional remanufacturing technology can effectively solve this problem and the key problem of predecisional remanufacturing is the determination of the optimal remanufacturing time.Then,this paper proposes a service research on timing choice of predecisional remanufacturing for diesel engine crankshaft based on online monitoring by taking diesel engine as an example.Firstly,the crankshaft of diesel engine was taken as the main research object,and the energy consumption model of the diesel engine crankshaft and connecting rod mechanism with gap was established.Then,the remanufacturability analysis of the diesel engine crankshaft was carried out,using R175 B diesel engine as a simulation test platform,the paramenters can be monitored,including the vibration,shaft center trajectory,cylinder pressure and other performance parameters.Using the crankshaft connecting rod journal wear as the test variable,under the setting working condition,the signal of diesel engine body sensitive position’s vibration and shaft center trajectory can be monitored.Finally,the vibration signal characteristic parameters of the crankshaft wear were extracted by wavelet packet analysis,and the shaft center trajectory characteristic parameters of crankshaft wear could be extracted by Hu`s invariant algorithm.The mapping relationships between the vibration characteristic parameters and wear quantity,shaft center trajectory characteristic parameters and wear quantity were established.By using these two sets of mapping relations.As the model diesel engine crankshaft connecting rod journal in the best remanufacturing correspond to the wear of 0.33mm(determined by the lowest energy consumption through the crankshaft full life cycle),the two characteristic parameters can be used as the basis for judging whether the same engine meets the remanufacturing requirement,and to achieve the crankshaft rough quality control.In this way,it provided a solution to the uncertain control problem of remanufacturing blank quality in the service period with the same batch product failure.