Optimization Studying On The Power Transmission System For Heavy Dump Truck

In the heavy duty trucks, dump truck, as a bulk cargo short-haul freight vehicle type, which always used for in addition to the grade road area,site and its loading goods are complicated and various. Because dump truck need to adapt bad use conditions such as high-frequency alternating load impact, overload low-gear high torque output, low speed driving, lifting, unloading and no-load high speed returning, the attention of users for its comprehensive performance is becoming more and more high. In this paper, a comprehensive evaluation system is established, which is suitable for the operating conditions and special conditions of dump truck. Under the system, TY-1dump truck as a basis vehicle whose performance is analyzed, and its power system parameters are optimized according to the analysis results at the same time. This analysis provides a certain theory basis for the evaluation and optimization of dump truck’s comprehensive performance.According to the automobile operation basic principle, the mathematical model of the dump truck’s powertrain including engine, gearbox, drive shaft and the drive axle is established with the help of MATLAB. Transmission shifting principle, the engine unstable condition, transmission efficiency and moment of inertia of each element are analyzed and disposed under the dump truck vehicle model,which provide theory support for performance analysis and optimization of dump truck.The comprehensive evaluation method suit for dump truck is put forward based on the survey of dump truck application conditions and user requirements when evaluating performance of dump truck. The maximum speed, acceleration and gradability,"six operating mode" and20km/h to80km/h constant speed fuel consumption as the dynamic performance and fuel economy evaluation indexes are unified dimension.After the determine of index weight coefficient, performance evaluation equation of dump truck is obtained.Establish and verify the dump truck model taking advantage of AVL Cruise. The dynamic performance and fuel economy are analysed based on the model, which provide theory basis for dump truck optimization.By doing sensitivity analysis for powertrain variable parameters including engine displacement, the ratio of the gear-box and axle ratio to determine the influence of various parameters on the dump truck vehicle performance. Results show that the engine displacement, maximum and minimum speed ratio of the transmission and axle ratio have higher sensitivity compared with other parameters. Due to the change of engine displacement involves the reset of the engine performance curve, and different engines comparability is small.This paper choose maximum and minimum speed ratio of the transmission and axle ratio as ptimize parameters.Sixty-four kinds of matching scheme are expanded on the basis of the original dump truck according to the principle of parameters selection and optimization.Using comprehensive evaluation equation made a detailed study on the improvement degree of the dump truck performance in all matching schemes and getting optimal match. The model of optimal dump truck is established. Do simulation calculation of optimization model about its power performance and fuel economy performance. Compared to the original truck, in addition to maximum speed slightly reduced within a reasonable scope, the optimized truck power performance and economic performance are improved largely.