Study On New Three-Parameter Shift Schedule Of Engineering Vehicle

Engineering Vehicles are widely used in infrastructure and mining industry, due to engineering vehicles working environment is extremely harsh and complex, in order to improve the engineering vehicle adapt to the complex environment of the outside, the kind of hydraulic mechanical transmission was widely used in the main transmission. Although the hydraulic mechanical transmission system is improve engineering vehicle overcome the heavy engineering capacity in the low-speed, in the same time, the transmission efficiency is filling; Also in the case of high-speed light load, if the transmission can not into high gear in time, the transmission efficiency will down. In order to ensure that engineering vehicle's power and transmission efficiency, automatic transmission technology is used in the system of the hydraulic mechanical transmission.In this paper, in order to improve the engineering vehicle dynamic and transmission efficiency, we do the research on the purpose of the engineering vehicle automatic transmission system with Doctoral Fund of Ministry of Education project "engineering vehicle new three parameters of automatic transmission technology" (No.200801830028). Use ZL50 wheel loader as the prototype, define the load factor by the maximum pump pressure, use the load factor to establish X6130 diesel engine continuous dynamic speed model. Select throttle angle, load factor, the speed as control parameters, use the characteristic curve of the traction of engineering vehicle to obtain the new three-parameter Shift Schedule of engineering vehicle to improve dynamic; use the efficiency curve of hydraulic torque converter to obtain the new three-parameters energy-saving shift schedule of engineering vehicle to improve transmission efficiency of hydraulic mechanical transmission system and improve economy. Obtain the law of the speed gear shift formula according to the speed point of order obtained by the different throttle opening under different load factor of a new three-parameter dynamic Shift Schedule and energy-saving Shift Schedule. Use the MATLAB/Simulink software, establish engineering vehicle hydraulic mechanical transmission system the simulation model and simulation tests. The following sub-section describes the research paper:Chapter 1 Introduction. Access to a large number of domestic and foreign vehicles in the automatic transmission on the basis of technical information, detailed introduce the classification of automatic transmission, vehicle automatic transmission technology and development process, describe the situation of the development of automatic transmission system at home and abroad, discusses the classification and control of engineering vehicle's shift schedule and car's shift schedule, Finally, this paper's research contents.Chapter 2 The model of engineering vehicle transmission and power analysis. Use the wheel loader as prototype, analysis the composition and characteristics of hydraulic mechanical transmission system, establish mathematical model of diesel engine, oil pumps, torque converter, and transmission respectively. For the complex to establish accurate mathematical model of diesel engines, establish a continuously differentiable, relatively high fitting precision dynamic continuous speed model of diesel engine. For the current complex to calculate pressure pump's torque and power, define a new parameter-the load factor, so describe the output characteristics of the transmission system dynamically. In order to reduce the error of calculation of resistance, according to the idea of engine power split, use of oil pump torque and power consumption to calculate the resistance, on this basis, derivate a mathematical model of hydraulic mechanical transmission system of engineering vehicles and define the conception of automatic transmission and provide a theoretical basis for dynamic simulation.Chapter 3 Study on engineering vehicle law of automatic transmission shift. According to the control parameters and optimization of different objectives, introduce the current classification of engineering vehicle shift schedule, and considering the main operating characteristics of the actual working conditions of engineering vehicles, define the three parameters, namely throttle angle, load factor and speed as the control parameters, introduce the method of obtain the new three parameters dynamically shift schedule and energy-saving shift schedule. According to the different maps obtain the different points of shift speed on different throttles,gears and load factors, use the least squares polynomial fitting method to obtain different speed formula to change gear on different throttles,gears and load factors. Chapter 4 Simulation and test of automatic transmission based on simulink. Based on the mathematical model and dynamic model of the engineering vehicle's transmission system, use MATLAB/Simulink and STATEFLOW kit to build the simulation model of engineering vehicle's automatic transmission, and simulate the new three-parameter dynamic and energy-saving Shift Schedule, then, compare the simulation results with two-parameters (throttle, vehicle speed) shift schedule, the results prove the new three-parameter dynamic Shift Schedule and energy-saving have better power and economy than two-parameters shift schedule.Chapter 5 Conclusions and Outlook. Summarize the research's results and innovation, outlook the future research's work.