Abstract: An air intake device includes a supercharger, a connection tube, an intercooler, and an intake manifold. The supercharger is connected to an exhaust port of a cylinder. The intercooler is connected to the supercharger through the connection tube. The intake manifold is connected to the intercooler and an intake port of the cylinder. The intercooler is located above a cylinder head of an engine. The device of the present disclosure features less height space occupation, a short connection tubeline between elements and a compact structure, which is beneficial for an increase of the pressurization response speed and reduction in the cost.

Abstract: A combustion control method and a combustion control system with variable excess air coefficient for gasoline engine are provided. The combustion control method with variable excess air coefficient for gasoline engine comprises steps as follows: monitoring engine operating condition; determining current engine load condition based on the engine operating condition, wherein the engine load condition comprises part load, high load, and full load conditions; and selecting an appropriate excess air coefficient combustion mode in accordance with the current engine load condition; wherein the engine uses lean combustion mode with excess air coefficient of 1.6˜2.0 when the current engine load condition is the part load condition; the engine uses combustion mode with excess air coefficient of 1 when the current engine load condition is the high load condition; and the engine uses combustion mode with excess air coefficient of 0.8˜0.9 when the current engine load condition is the full load condition.

Abstract: An air intake duct includes an air intake duct body (11) which includes an air intake part (111) and a connecting part (112) connected with the air intake part (111). A first channel is formed inside the air intake part (111), a second channel intercommunicating with the first channel is formed inside the connecting part (112), one side of the connecting part (112) is provided with a connecting surface (112a) which inclines towards an axis of the air intake duct body (11), the connecting surface (112a) is inclined and extended from a connection joint of the connecting part (112) and the air intake part (111) to an end portion of the connecting part (112), and the first channel has a larger cross section area than the second channel.