Air inlet control method and device capable of arranging throttle valves at different cylinders separately

Abstract

The invention relates to the technical field of engines, in particular to an air inlet control method capable of arranging throttle valves at different cylinders separately. The method is characterized in that corresponding branch pipe throttle valves are arranged at ends of branch pipe outlets of corresponding air inlet manifolds of the air cylinders, the air inlet amount needed inside each cylinder can be controlled through the magnitude of the aperture of the corresponding branch pipe throttle valve, and then, air in each air inlet manifold is boosted, so that the air pressure inside the air inlet manifold can be kept to be higher than the pressure of residual waste gas inside the cylinder when the air inlet is opened. Due to the fact that each cylinder is provided with one corresponding branch pipe throttle valve, the air pressure in one cylinder cannot interfere with the air pressure in another air cylinder, and the phenomenon that waste gas flows back to an air inlet channel is avoided. Meanwhile, at the position near a top dead center, when the air inlet and an exhaust valve are opened at the same time, the forced scavenging conditions that the outer pressure of the air inlet capable of achieving more thorough scavenging is sequentially higher than the pressure inside the cylinder, and the pressure inside the cylinder is higher than the pressure of the exhaust manifold are formed, and high-temperature residual waste air inside the cylinders is exhausted more sufficiently.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to an air intake control method and pressure device in which throttle valves are independently set for each cylinder. Background technique [0002] At present, multi-cylinder naturally aspirated gasoline engines use a general throttle valve to control the intake air volume of each cylinder at the same time through throttling and pressure reduction. The air pressure in the intake manifold is always lower than atmospheric pressure, and it is required to be The less the intake air volume is controlled, the lower the pressure; in the process of exchanging air for each cylinder, the intake valve usually needs to be opened at a certain advance angle before the end of the exhaust stroke. The residual exhaust gas pressure in the cylinder is higher than the pressure in the intake manifold, so that the exhaust gas flows back into the intake manifold, and then flows back into the intake manifo...

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Problems solved by technology

[0002] At present, multi-cylinder naturally aspirated gasoline engines use a general throttle valve to control the intake air volume of each cylinder at the same time through throttling and pressure reduction. The air pressure in the intake manifold is always lower than atmospheric pressure, and it is required to be The less the intake air volume is controlled, the lower the pressure; in the process of exchanging air for each cylinder, the intake valve usually needs to be opened at a certain advance angle before the end of the exhaust stroke. The residual exhaust gas pressure in the cylinder is higher than the pressure in the intake manifold, so that the exhaust gas flows back into the intake manifold, and then flows back into the intake manifold as the volume in the cylinder increases and the pressure decreases during the intake process. Part or all of the exhaust gas will be sucked into the cylinder with the fresh air, and this part of the exhaust gas will be superimposed with the residual exhaust gas that is not discharged in the cylinder itself to form the sum of the residual exhaust gas in the cylinder; this phenomenon will lead to various problems: every cycle of the engine There is a considerable degree of high-temperature residual exhaust gas that cannot be discharged, resulting in a high base temperature of the mixture in the cylinder after the intake is completed, which limits the maximum compression ratio that the engine can adopt, so the thermal efficiency of the engine is not high; because the backflow of exhaust gas is affected by engine speed, cylinder Internal and external pressure and pressure difference, valve opening, action time, temperature and other random factors are very complex, and the basic parameters fluctuate greatly, making it difficult to accurately control the temperature of the mixture in the cylinder and the coefficient of residual exhaust gas; fouling Throttle, affecting its normal work, etc.

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