A bypass valve and engine crankcase ventilation system with bypass protection structure

Abstract

The invention discloses an engine crankcase ventilation system provided with a bypass protection structure. The engine crankcase ventilation system provided with the bypass protection structure comprises an air cylinder head cover assembly and a crankcase ventilation system connected with the air cylinder head cover assembly. The crankcase ventilation system is connected with an air intake manifold resonant cavity through a pipeline. A bypass valve is arranged between an air outlet of the air cylinder head cover assembly and an air intake manifold assembly and is connected with the crankcase ventilation system in parallel. When the pressure of the air cylinder head cover assembly is higher than external atmospheric pressure in position, the bypass valve turns on. The bypass valve is higher than the air outlet of the air cylinder head cover assembly. When the crankcase ventilation system is shut down, the pressure of a crankcase rises, the bypass valve turns on, the air in the crankcase enters the air intake manifold assembly, the pressure of the crankcase drops to negative pressure, and then the bypass valve turns off. The bypass protection structure can turn on or turn off according to the relation between the pressure of the crankcase and the atmospheric pressure so that the pressure of the crankcase can be adjusted to become negative pressure, and consequently reliable operation of a whole engine can be guaranteed.

Description

technical field [0001] The invention relates to an engine, in particular to the structure of the engine crankcase ventilation system. Background technique [0002] When the engine is working, due to the difference in working efficiency, there is always a part of the combustible mixture and exhaust gas passing through the piston ring into the crankcase, and the gasoline vapor condensing into the crankcase will make the engine oil thinner, the performance will deteriorate, and the exhaust gas will The water vapor and sulfur dioxide contained in it have a corrosive effect on the engine. In addition, because the combustible mixture and exhaust gas escape into the crankcase, the pressure of the crankcase will increase, and the engine oil will leak from the crankshaft oil seal, crankcase liner, etc., and the oil vapor lost to the atmosphere will increase. Engine pollution of the atmosphere. Therefore, the state stipulates that the engine must be equipped with a crankcase gas pur...

AI Technical Summary

Problems solved by technology

However, there are disadvantages in this arrangement: on the one hand, because the temperature on the side of the intake manifold is relatively low, on the other hand, due to the complex structure and long pipeline of the entire crankcase ventilation system, in winter (especially in the north), the crankcase blow-by gas The water vapor in the above-mentioned devices and pipelines will condense into ice, block the pipelines, and cause the crankcase ventilation system to fail

After the crankcase ventilation system fails, the above-mentioned phenomena such as oil deterioration, oil seal detachment, and atmospheric pollution will occur, causing damage to the engine.

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