【作者】 秦永刚；

【导师】 杨士敏；

【作者基本信息】 长安大学 ， 机械电子工程， 2010， 硕士

【摘要】 工程机械的动力性和燃油经济性对于推土机这类循环作业式机械显得尤为重要。研究推土机的动力性和经济性对于提高其生产率、降低燃油消耗有着重要意义,符合当前节能环保和低碳的社会发展趋势。本文在综合国内外研究现状的基础上,对推土机各总成和整机的工作状态进行了运动学和动力学分析,进而对推土机各总成和整机的数学模型进行了分析或建模,得出了从推土机水平推土阻力到发动机转矩的转换方程,为探讨推土机的动力性、经济性模拟仿真方法提供了基础。推土机的水平推土阻力的急剧波动,对动力性的发挥和经济性的提高有着重大影响。论文在土体破坏理论的基础上,对推土机的推土阻力进行了分析,得出了静态牵引力的表达式。论文在对文献中T180推土机水平工作阻力现场实验数据进行分析的基础上对推土机动态水平推土阻力平稳随机信号的连续功率谱进行了周期离散化处理,在系统仿真软件AMESim环境下对动态水平推土阻力进行了数字化模拟,其结果与原实验信号吻合较好。论文在分析推土机整机理论模型和和对动态水平推土阻力模拟的基础上,在AMESim仿真软件环境下,建立了发动机仿真模型,在不考虑惯性力的前提下,建立了动态水平推土阻力到驱动轮力矩,再到发动机阻力矩间的静态转换仿真模型,最后利用AMESim仿真软件,对推土机的动力性、经济性进行了动态水平推土阻力工况下的静态仿真,得出了发动机在动态阻力矩作用下的输出功率、平均有效压力、输出转速以及燃油消耗量。利用仿真软件,对推土机的调速其实转速进行了搜索,得出了这一特定工况下的发动机调速起始转速的较优值,此时发动机输出功率较大,耗油量较低。论文所提出的仿真方法和思路,可为工程机械的动力性、经济性研究提供借鉴和参考。更多还原

【Abstract】 Power performance and fuel economy of construction machineries is very important for the cycle-operational machines such as Bulldozer. Through researching Power performance and fuel economy of Bulldozer has significant meaning in improving productivity and decreasing fuel consumption, and meeting the current energy saving and low-carbon society’s development trends.Based on synthesizing research status at home and abroad kinematics and dynamic have been analyzed in assembly and working state of bulldozer. Then, mathematical model of assembly of bulldozer and whole machine have been analyzed or modeled. In conclusion, the conversion equations of the bulldozers from the bulldozing resistance to the engine torque have been obtained which provides the basis for the momentum and economical simulation methods of bulldozers.The sharp fluctuations in horizontal bulldozing resistance of bulldozers have important effects on power performance and fuel economy. Based on the soil failure theory the resistance of bulldozer has been analyzed, and the expression of static traction has been obtained. Based on the research of the work-site experimental data from horizontal bulldozing resistance of T180 bulldozers in the reference the power spectral density function of continuous stationary random signal in dynamic resistance of the level of earth-moving bulldozer has been transformed into the discrete-periodic signals. By Simulated dynamic level of bulldozing resistance digitally under environment of simulate-software Advanced Modeling Environment for Simulations of engineering systems (AMESim), it can be seen that the results agree well with the original test signal.Based on theoretical model of bulldozers analyzed and dynamic level resistance simulated the engine simulation model has been established under AMESim, and the transform model has been established from the dynamic level resistance of bulldozing to the driving wheel torque by without considering the inertial force of the premise. Then the static converting-simulation model has been obtained in resistance torque of engine. At last, output power, mean effective pressure, output speed and fuel consumption in dynamic drag torque of engine have been obtained, as driving force and economy of the bulldozer have been simulated in dynamic level of bulldozing resistance condition by AMESim. Through searching engine start speed in regulation of bulldozers by AMESim, optimum value of the engine start speed has been obtained in particular initial condition which means at that time the engine output power is larger but fuel consumption is less.The simulation methods and ideas which have been proposed in this paper will provide references for researching in driving force and economics of construction machineries.更多还原