汽车发动机电控水泵冷却系统的设计及试验研究

    Both pump and fan are driven by engine in conventional cooling system, The rotation speeds of them are restricted to the speed of crankshaft. Water pump and fan revolve when cold-starting of engine, the heat of cylinder block is drawn off by circulating water and emits into the air. Therefore, warming time is prolonged; while the engine load changing suddenly from large to idle, the engine overheats due to the excess heat that is not drawn off in time with the the lower speed of pump and fan. Effective power of engine is also wasted by the work of pump and fuel consumption increased.To solve the problem of the over-heating and slow warm-up in the transportation of automobiles, a cooling system that contains electronic pump is designed.The issue is part of Provincial Education Department’s research project which is precise control of heat capacity in agricultural machinery. The cooling system contains electric pump and fan which are not driven by engine, independent control of electric fan has already been studied, but independent control of electric pump has not been studied according to the conclusion of sci-tech novelty searching. Microcontroller outputs PWM control signal to control the speeds of electric pump and fan according to temperature control program. This cooling system overcomes many shortages existed in traditional cooling system and can automatically adjust cooling capacity according to engine cooling requirement.This research mainly includes the following parts: the over-all design of this cooling system, hardware design and choosing of the control system, software design and tests of this control system. Hardware design of this control system lies in the interface circuit design, while software design mainly include: main control mode design, interruption processing design, filter design, temperature sampling mode design and alarming mode design, etc. According to the test results by Shandong Province Agricultural Machinery Product Quality Supervision and Inspection Station, the cooling system not only can solve the the problem of the over-heating and slow warm-up in the transportation of automobiles, but also has many other advantages, such as flexible installation, fuel saving, low nosing, small volumetric, and low power consumption, etc. This kind of cooling system suit the development of modern engine cooling system, after using this kind of cooling system in automobile engines largely, we will profit more from this device socially and economically.