Research And Application Of Reductive Fuel Consumption Technique On Piston Set

Market competition and fuel consumption rule force the car maker to seek the new techniques for reducing the fuel consumption.The friction from the piston sets which consist of piston and rings share 45%~55% in engine mechanical friction,so it is a effective way to reduce the fuel consumption by lowering the friction on the piston sets.Base on the original piston sets of one type of 1.6L engine,the new low-fraction techniques were applied to get the fuel consumption earning.Those techniques are new coating,lower friction coefficient and increase of clearance.Piston sets running with a lower resistant,the engine friction loss will be smaller,and the fuel will be more efficient.The whole value of consumption earnings is small that there will be an offset measured by the bench test.The usual bench test measurement contain the offset caused by instrument,samples difference,samples endurance or the statistics scatter,and it will lead a not exact evaluation of fuel consumption earning.This paper suppose a calculation of the fuel consumption earning from the lower piston set friction loss,and it is compared with the bench test and vehicle measurement.At last,analysis and validation are implied due to negative effect from the increase of clearance.Firstly,measure engine torque loss of original and new piston sets by drag motor test.From measuring in different the oil temperature,the relationship among the mechanical torque loss,engine speed and oil temperature is studied.Combining the calculation and drag measurement,build the engine mechanical torque loss model,and this model can be as the input of following simulation.The drag motor method has a imperfection,the result contains the pumping torque loss inevitably when the electrical motor drag the engine.If the mechanical torque loss is not exact,it will lead a deviation of fuel consumption calculation.The measurement value of torque loss from drag engine test can be compared with the calculation value,the pumping torque loss can be acquired,and then the correct mechanical torque loss model is found.Then set the engine model in the AVL BOOST software,input the mechanical friction loss of the original and new piston set,and simulate the fuel consumption.The result which relate to the different air load?engine speed can be compared with the bench test measurement.Simultaneously,estimate the fuel consumption and measure the real fuel consumption in the NEDC cycle base on the original and the new piston sets.At last,the extending cylinder-piston gap must be in a reasonable range,and the noise maybe enhanced,the analysis and test are carried out to research this issue.Base on the finite element method,do analyses of the piston transformation under thermal and mechanical loads and estimate the cylinder-piston gap adaption is reasonable or not.Build the piston motion model and force model,and study the maximum lateral force variable cause by gap adaption.The vehicle noise is validated to compare original and new piston sets.The studies indicate that,the lower friction techniques can gain a proper fuel consumption earning,and the cylinder-piston gap adaption is reasonable.