汽车发动机冷却系统智能控制技术的研究论文.doc

PAGE 本科毕业论文 （2010届） 题 目 汽车冷却系统智能控制研究 学 院 机械工程学院 专 业 车辆工程 摘要 本课题是对传统汽车发动机冷却系统的一些弊端进行改造设计。由于汽车发动机传统冷却系统的风扇、水泵、节温器工作的协调性较差，传统控制模式限制了发动机在不同工况下的适应性，尤其是在恶劣的工况下过热导致的发动机工况异常。为改变这种状况，先对冷却风扇、水泵、节温器的受控因素进行一定研究，测量水温、空气流量、发动机转速等对冷却系统智能控制重要的传感参数。在此基础上，对冷却系统整体智能控制进一步进行研究。智能控制系统将根据发动机冷却水温、空气流量、发动机转速等参数，以单片机为智能控制核心元件，实现风扇转速、电控导风板和节温器的开闭随发动机工况变化自动调节的目的。该智 能控制系统可缩短发动机预热的时间，提高热效率，增强了冷却系统在发动机不同工况下的适应能力，实现对冷却水温的精确控制，降低汽车的燃油消耗，达到提高发动机工作可靠性和使用寿命的目的。 关键词：冷却系统；智能控制；单片机；节温器；传感器 ABSTRACT This subject redesigns traditional vehicle engine cooling system to avoid some abuses. Because of the bad working coordination among fan，water pump and thermostat in traditional vehicle engine cooling system，traditional controlling pattern 1imits the engine’s adaptability in different working conditions，especially engine’s working condition anomaly caused by over heat because of bad working conditions. Then the paper further researches the whole intelligent control of cooling system. The intelligent control system with single-chip computer as it’s core element will achieve self-regu1ation of the opening and shutting of fan rotational speed，electrically controlled baffle plate and thermostat along with the engine’s operating condition，according to the parameters of engine’s cooling temperature，air flow and engine’s rotational speed. To change this condition，the paper first researches the controlled factors of cooling fan, water pump，thermostat，and surveys the sensing parameters of water temperature，airflow，engine speed，which play important roles in intelligent control of cooling system. This intelligent control system can shorten engine’s preheating time，enhance thermal efficiency，strengthen the cooling system’s adaptability under engine’s different operating condition，control the cooling temperature accurately，reduce the automobile’s fuel consumption，and help to enhance the engine’s operational reliability and service life. Keywords: Cooling system; intelligent control; Single-chip computer; thermo