A cylinder head for a partitioned and stratified lean-burn engine

Abstract

The invention discloses a sectional and layered lean-burn engine cylinder cover. The sectional and layered lean-burn engine cylinder cover is connected to a cylinder on the engine. A sectional partition is arranged on the cylinder cover and divides a combustion chamber of the cylinder into a small combustion area and a large combustion area. According to the combustion chamber structure, fuel combustion efficiency of the engine is improved in the case of idling and low and middle load of the vehicle, waste gas exhausted and fuel combustion of the engine are reduced, safety utilization of the engine in the case of large load is guaranteed, and accordingly environmental performance of the vehicle is improved during driving, with lowered cost required.

Description

Technical field [0001] The invention relates to the technical field of engines, in particular to a cylinder head for a zoned and stratified lean burn engine. Background technique [0002] At present, the most widely used automobile engine is the reciprocating piston engine. This kind of engine achieves fuel economy through turbocharging at high speed and heavy load, but it fails to achieve fuel economy at idle speed and light load. Fuel consumption is obviously too high when driving at low speed in the area. [0003] The reasons are as follows: (1) When the throttle is completely closed at idling speed, only a small amount of air enters the cylinder through the throttle idling passage, so that a large vacuum is formed during intake, which will inevitably cause the energy consumed by the intake. Increase, increase the pumping loss; at the same time, because the vacuum degree of the intake pipe is very large at this time, when the intake valve is opened, the pressure in the cylinder...

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Problems solved by technology

[0002] At present, the most widely used automobile engine is the reciprocating piston engine, which achieves fuel economy through turbocharging at high speed and heavy load, but fails to achieve fuel economy at idle speed and light load, so it is used in the market. Significantly high fuel consumption when driving at low speeds

[0003] The reasons are as follows: (1) When the throttle valve is completely closed at idle speed, only a small amount of air enters the cylinder through the idle passage of the throttle valve, so that a large vacuum is formed when the air is inhaled, which will inevitably reduce the energy consumed by the intake air. increase, increasing the pumping loss; at the same time, because the vacuum degree of the intake pipe is very large at this time, when the intake valve is opened, the pressure in the cylinder is higher than the pressure of the intake pipe, and the exhaust gas expands into the intake pipe. During the suction stroke, The exhaust gas and the new mixed gas are sucked into the cylinder at the same time. In order to ensure the normal combustion of the mixed gas diluted by the exhaust gas, more fuel must be supplied to enrich the mixed gas, which will inevitably increase the fuel consumption; (2) under small load At this time, the opening of the throttle valve is very small, so that a large vacuum is formed when the intake valve is opened. When the intake valve is opened, the pressure in the cylinder is also higher than the pressure of the intake pipe. During the intake stroke, part of the exhaust gas also expands. Into the intake pipe, in order to ensure the normal combustion of the mixed gas diluted by exhaust gas, more fuel must be supplied, which increases fuel consumption, which is one of the important reasons for the high fuel consumption of cars in urban areas; (3) At idle speed, small load, and medium load, the intake pipe throttling method is used to adjust the amount of the mixed gas charge. The throttle valve is not fully opened, forming a certain degree of vacuum, which increases the pumping loss, especially at idle speed and small load. When the air pressure increases, the pumping loss increases significantly. At medium load, the throttle valve opening is relatively large, resulting in a small vacuum. Although the loss of each suction stroke is not large, more than 60% of the engine is in this working condition. , so the total amount of pumping loss increase is still very large; (4) The mixture of conventional gasoline engines is homogeneous, generally only works within the range of air-fuel ratio 12-17, and burns near the stoichiometric ratio, so that NOx higher emissions

In order to prevent deflagration, a lower compression ratio is used, especially at idle speed and light load, the air-fuel ratio is much smaller than the theoretical air-fuel ratio, resulting in low thermal efficiency

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