The Dynamic Characteristics Of The Gasoline Engine Electronic Governor

These days, the internal-combustion engine applied in the agricultural machinery, such as plant protecting machine, horticultural machine, are mainly small-scale gasoline. In the course of work, the gasoline often works with its load changing constantly, which leads large fluctuation of ratio speed, the ratio speed can be stabilized by change the opening degree of the butterfly valve. Therefore, speed governor must be adopted on the gasoline engine. And now the most applied speed governor is of mechanical with lower adjustment ability and longer time of transmission. With the further application of the small-scale gasoline, the demand to the engine also increases. To meet the demands of market and improve the performance of the engine, the experiments of digital electronic governor on small gasoline engines have been carried out to obtain data.Analyzing the situation of the electric governor systematically, this paper research into the measures to improve the dynamic characteristics in the middle of transmission of the electronic governor. The relation between the change of the speed and the change of the butterfly valve has been addressed, and the impact the adjustment amount on the dynamic characteristics has been discussed. The control of fragmental digital PED is adopted to improve the dynamic characteristics of electronic governor based on the feature of the transmission period, such as improving dynamic state response speed of electronic governor, ameliorating ratio of instantaneous modulation, eliminating over speed in time and shortening stable time.The electronic governor depends on controlling software to realize the function of regulation and control, keeping the rotational speed of the petrol engine within the range given while the load being changing. The shortcomings of mechanic governor are overcome. Characteristics, such as ratio of stable and instantaneous modulation, the time lasting, can be controlled by program. The electronic governor is versatile and possesses extensional ability. The executive mechanic is a four-phrase motor, which transform the electric pulses into angular signals. If the software is appropriate, the throttle can be driven directly. The electronic governor has high precise of control, and the control system is simple with fewer components and higher reliability.The result of a number of experiments shows that when the speed of the gasoline engine is 3000 rpm. Ratio of instantaneous modulation of the electronic speed governor can reach 5.8% and its stabilization time can reach 3.1s. And the test results are superior to the national sector standard. The whole electronic governor is worth a wide popularization for its simple structure and lower price.