Search

The electric three-way proportion valve is used for the control of the large and small coolant circulation flows of internal combustion engine. The fuzzy control principle is applied to the control of the opening of proportion valve, and hence the regulation on the large and small coolant circulations of engine is realized. The control strategy is verified on the simulation test bench of engine cooling system with the coolant temperature and its changing rate as inputs and the increment of the opening angle of proportion valve as output of fuzzy controller. The results show that the fuzzy control strategy has high control accuracy and fast dynamic response, and can achieve the rational distribution of the large and small coolant circulations of engine coolant, assuring the engine working on the most suitable coolant temperature condition. [ABSTRACT FROM AUTHOR]

The effects of external heat source on the start and warm-up process of engine are studied by heating the cooling water of engine with electric heater. 6 schemes are arranged for experimental study, including original, synchronous heating, preheating, warm start, preheating + synchronous heating and warm engine + synchronous heating, with the effects of different schemes on the temperature rises of cooling water, oil and exhaust gas and engine speed emphatically analyzed. Experimental results show that the basic schemes of synchronous heating, preheating and warm start all lead to different degrees of improvement in building up water and oil temperatures during engine start; while the combination schemes of preheating + synchronous heating and warm engine + synchronous heating further amplify the effects of start performance improvement by basic schemes and also reduce the consumption of energy. [ABSTRACT FROM AUTHOR]

By using Compact RIO controller made by NI company as control core and adopting the PID controller of Labview software, wave generator and special control components including FPGA toolkit, a hydraulic fatigue test system for engine crankcase is developed, and the loading of hydraulic pressure, the collection of strain signals at the specific points of crankcase and the closed-loop control of hydraulic servo solenoid are realized. With the change in strain values at specific points as the criterion of crankcase crack, the on-line identification of the fatigue failure of engine crankcase is realized. [ABSTRACT FROM AUTHOR]