Atkinson cycle engine combustion system

Abstract

The invention discloses an Atkinson cycle engine combustion system which comprises a cylinder cover and a piston. The design that the compression ratio of the piston is within the range from 4 to 12 is met, a top face of the piston is designed to be of a protruding structure, and the central area of the top face is designed to be in a concave spherical structure. Lift ranges of an exhaust valve, a first intake valve and a second intake valve are non-variable-valve lift ranges. The valve motion of the first intake valve and the valve motion of the second intake valve are driven by the same mechanism, the motion curves of the first intake valve and the second intake valve are not symmetrical and form an oblique axis vortex, the first intake valve and the second intake valve respectively comprises the lift range and a phase, vortex motion is formed in the air inside the cylinder due to the asymmetrical phase design, the asymmetrical design is combined with tumble and vortex and forms oblique axis vortex, and form much stronger turbulent motion at the ignition moment, and therefore the combustion efficiency is improved. According to the Atkinson cycle engine combustion system, on the premise that an original cylinder cover is not changed, due to the reasonable design of the valve motion and a combustion chamber, the combustion efficiency of the Atkinson cycle engine can be improved, therefore, a part of load oil consumption is reduced, and the low-speed torque is improved. The Atkinson cycle engine combustion system has the advantages of being simple in structure and easy to implement.

Description

technical field [0001] The invention relates to the field of internal combustion engines, in particular to an Atkinson cycle combustion system and structural design. Background technique [0002] As hybrid vehicles become the focus of the future development of the automobile industry, Atkinson cycle gasoline engines with high thermal efficiency and low power have become the research focus of various automobile companies again. The Atkinson cycle gasoline engine is used in hybrid vehicles. When the engine power is insufficient, the motor is used to assist, thereby reducing the power demand of the vehicle for the engine. Therefore, when developing the Atkinson cycle engine for hybrid vehicles, more attention should be paid to Low fuel consumption under partial load of the engine, while power at high speed can be sacrificed appropriately. [0003] Atkinson cycle gasoline engines currently used in hybrid vehicles use high compression ratios and late closing of intake valves to ...

AI Technical Summary

Problems solved by technology

However, this design has the following problems: modern gasoline engines generally pursue high power at high speeds, and mostly adopt symmetrical double intake port structures and symmetrical valve movement rules, and the intake ports are designed to have high flow coefficients and low tumble coefficients.

During the development of the Atkinson cycle gasoline engine, the structure of the cylinder head is not changed, and the tumble flow intensity formed by the intake port guidance is difficult to increase; in addition, because the Atkinson cycle gasoline engine adopts the strategy of closing the intake valve late, the tumble flow intensity in the cylinder is further improved. weakening, which makes the combustion more slow, the thermal efficiency decreases, and even misfire occurs in severe cases; the flat-top protrusion on the top of the piston designed for the high compression ratio will further affect the combustion of the mixture in the cylinder, and the tendency of knocking is serious under low speed and high load, resulting in Low speed torque deterioration

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