Research On Timing Silent Chain System Dynamics Considering The Coupled Vibration Of Internal Combustion Engine System

As the key component of internal combustion(IC)engine,the dynamics of timing silent chain system takes important influence on the fuel economy and NVH performance of IC engine.The conventional analytical model of timing silent chain system only focus on chain system without considering the influence of IC engine coupled vibration.In this paper,the timing silent chain system dynamics model considering coupled vibration of engine system dynamics was established.The impact of coupled vibration of engine system on the NVH performance of timing silent chain system was investigated.Based on the elastic vibration theory,the analytical model of engine system elastic vibration response was created,in which the characteristic of engine block,crank-rod mechanism,value trains and timing silent chain system were taken into consideration.The dynamical analytical model of timing silent chain system(TSC),TSC with valve trains(TSC+VT),and TSC+VT with engine system were constructed by AVL EXCITE software,and then the dynamical characteristic of timing silent chain system was analyzed under maximum torque and maximum power.By comparing the parameters such as chain link angular velocity,chain link trajectory,the contact force between chain link and parts of timing drive system,forces applied fixed rail,sprocket angular velocity fluctuation and chain tension at each section etc.,the influence of coupled vibration of IC engine system was discussed in details.The influence of crankshaft speed fluctuated and preload hydraulic extender to dynamical characteristic of timing silent chain system was investigated.The simulation results showed that the crankshaft speed fluctuated have a strong effect on the contact force between chain link and parts of timing drive system,and with the increase of preload hydraulic extender following kinds of force increased,such as the tension force,the contact force between chain link and sprocket and chain tension at each section while sprocket angular velocity fluctuation decreased.The chain tension force was measured by dynamical strain response on engine vibration test bench by gauge strain,on which the tension force was validated by a special device.A comparison was carried out between the simulation results and measured date,the results showed that the simulation result of tension force was well accordance with the measure data.The timing silent chain system dynamical model considering coupled vibration of engine system dynamics was verified.