Atkinson cycle implement method for natural air suction gasoline engine

Abstract

An Atkinson cycle implement method for a natural air suction gasoline engine comprises the following steps: (1) a high-energy ignition coil is used, and the ignition energy of the ignition coil is atleast 80 mJ; (2) an EGR pressure stabilizing cavity is integrated on an air inlet manifold, the EGR system takes exhaust gas from the outlet of an exhaust manifold, and the exhaust gas enters the EGRpressure stabilizing cavity after passing through the EGR system, and the exhaust gas is gathered in the EGR pressure stabilizing cavity and evenly distributed to each branch pipe of the inlet manifold; (3) a high-rolling-flow air inlet channel is used for matching a piston with a shallow pit on the top surface; (4) the intake camshaft is of a variable valve phase system, the phase adjustment angle of the intake valve is 58 DEG crankshaft angle, the delay closing of the intake valve is achieved, the maximum delay closing angle of the intake camshaft is maximum above 100 DEG crankshaft angle after the bottom dead center, and the effective compression ratio of the engine is adjusted. According to the method, the low-load misfire rate can be effectively reduced, high-load knocking can be restrained, the intermediate load heat efficiency is improved, and the combustion stability of the whole working condition is improved.

Description

technical field [0001] The invention relates to the technical field of internal combustion engines, in particular to a method for realizing the Atkinson cycle of a naturally aspirated gasoline engine. Background technique [0002] The fourth phase of the fuel consumption standard "GB 27999-2014 Passenger Car Fuel Consumption Evaluation Method and Index" will be implemented in 2020, requiring the average fuel consumption level of new passenger cars in my country to drop to about 5L / 100km by 2020, corresponding to carbon dioxide Emissions are around 120g / 100km. In addition, the "Parallel Management Measures for Average Fuel Consumption and New Energy Vehicle Credits of Passenger Vehicle Enterprises" came into effect on April 1, 2018, which supports and encourages hybrid and pure electric vehicles, and will reduce the fuel consumption of traditional automobile enterprises. punished. The Atkinson cycle engine technology used for hybrid power has the characteristics of high ther...

AI Technical Summary

Problems solved by technology

[0003] The Atkinson cycle is realized on the naturally aspirated gasoline engine, mainly through the late closing of the intake valve to achieve and increase the compression ratio. The late closing of the intake valve can adjust the effective compression ratio and also achieve the purpose of the expansion ratio being greater than the compression ratio. Late closing of the intake valve causes most of the oil and gas to flow back into the intake port and intake manifold, resulting in difficult control of the air-fuel ratio and unstable combustion

At present, if we only increase the compression ratio, increase the opening angle of the intake valve, and adjust the opening and closing time of the intake valve through the intake VVT, although the Atkinson cycle can be realized, it is difficult to ensure the stability of combustion, which will High load is easy to knock, low load is easy to catch fire, and the thermal efficiency of intermediate load is not high, and the final thermal efficiency is not significantly improved.

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