Matching And Control Strategy Of Continuously Variable Transmission System With Its Efficiency Repaired

Continuously Variable Transmission (CVT)can improve fuel economy and performance of vehicle, therefore it is an ideal transmission and always concerned by engineers. In the case of unchanged engine, it can improve fuel economy and performance of vehicle through two followed sides: (1)to establish more ideal strategy,(2)to improve the efficiency of parts of CVT.Efficiency of CVT has been analyzed. The matching strategies have been repaired with efficiency and compared through Matlab simulation. All of the work are financed by National Natural Science Foundation from the project (50122101). In the case of constant hardware, it can improve fuel economy and performance of vehicle hopefully when the repaired strategy in place of original strategy. This paper involves followed content: 1) On the basis of comparison of three kinds of transmissions, the technology of CVT was pointed out as developing tendency for the transmission of passenger car. It presents the development and application of CVT and summarizes the research of CVT.2) The transmission mechanism is the foundation of calculation of CVT efficiency. By analyzing the working forces on blocks?rings and axial forces on pulleys of the metal pushing V-belt during torque transmitting, what the power transmitting is the mutual results of the blocks and rings is pointed out, and formulae for calculating the working forces and the axial forces on pulleys are deduced.3) The efficiency of the CVT is an important factor for weighing CVT performance. Based on the mechanical analysis, by synthetically the effect of the viscosity lubricant on the power loss of CVT, the formulae of efficiency is established. The Calculation of efficiency was done, getting two efficiency trend charts. One is efficiency with torque and rotational speed variation .The other is efficiency with torque and ratio variation. The two charts are guidance in formulating matching and control strategy and in efficiency experiment. 4) Based on the JL474Q1 engine experiment, torque and oil consumption model of engine are established by method of spline interpolation. The optimum economy and performance curves are put forward without considering CVT efficiency. The matching and control strategy of CVT and engine is repaired with CVT efficiency. The Strategies of fuel economy and performance are established. 5) On the basis of model of CVT simplified, simulation model of vehicle isestablished from Linyang7130 vehicle as research object. It makes the vehicle work according to the two strategies which are repaired with efficiency or not in simulation. The fuel economy is estimated by fuel consumption of an ECE15 city cycle. The performance is estimated by the needed time of acceleration from zero to 100km/h with throttle opened entirely.