Study On Simulation Of Combined Type Governor For Diesel Engine

Under the dieselization development process of the world power, and facing the challenge of dual problem of resource and environment, the field of how to make the diesel engine power resource conservation and environmentally friendly has become a research hotspot. The speed governor, as an important part of diesel engine speed control system, is now getting more wide attention. But the fact is, due to the restriction of historical circumstances and self-inadequacy, the domestic study on speed control field still exists large space to consummate and even fill the gaps. Aiming at the current situation of lack in modeling and simulation study on the key component of diesel engine speed governor, this graduation thesis takes a combined type speed governor as the object of study, and the simulation study on the key components of the mechanical hydraulic part and the electrical hydraulic part has been made respectively, including the following several sections:Combining the current developing and research situation of speed governor domestic and overseas, aiming at the study combined type speed governor, this thesis has given out the operating principle and mathematical model. In addition, the AMESim simulation models of controlling valve and actuator of the mechanical hydraulic part and the Maxwell simulation model of ratio electromagnet of the electrical hydraulic part have been established.The characteristic analysis of controlling valve has been given, and through the simulation of the initial parameters and the variable study on governing spring stiffness, controlling valve mass and flyweight mass, the optimization simulation has been made. And the verification goes straight after that.The simulation analysis of the actuator has been made with the controlling valve optimized parameters and the actuator parameters. Through simulation, the response characteristic and pressure characteristic of controlling valve, the response characteristic of power piston have been gotten.The characteristic analysis of ratio electromagnet of the electrical hydraulic part has been made, and the relation between electromagnetic force and excitation current, the relation between electromagnetic force and push rod displacement have been gotten. Besides, the variable study has also been made.The simulation results show that:the response time of controlling valve is 5.2s with the initial parameters, and there exists obvious vibration. The influence of governing spring stiffness, controlling valve mass and flyweight mass to the governor working process are quite big. After the optimization, the response time is cut down to 0.2s. The actuator could accomplish output shaft displacement quickly and accurately to adjust the change of the load. The parameters set of the ratio electromagnet of the electrical hydraulic part is proper. Under the affection of rated current, the effective displacement of ratio electromagnet push rod is between 0.5mm and 4.5mm, the electromagnetic force average value remains at 151N, which is basically conform to the 4mm effective displacement and 145N rated force of the study ratio electromagnet.