Diaphragm type PCV valve

Abstract

The invention provides a diaphragm type PCV valve which can decrease abnormal sound. The diaphragm type PCV valve comprises a hollow shell and a film in the shell. The shell is provided with an air outlet and an air inlet respectively on the lower part and the lateral part of the film. A big spring is fixed at the air outlet. The top of the big spring is connected with a big spring bracket which is provided with a through hole on the bottom. A supporting block is fixed at the position of the film corresponding to the big spring bracket. A small spring is fixed on the periphery of the supporting block. A small spring bracket is disposed on the bottom of the small spring. The middle part of the small spring protrudes upwards and extends into the small spring. A through hole is arranged on the part of the small spring bracket which is inside of the small spring. With a supporting block and various guiding structures, the PCV valve can fully induct air in a crankcase into an induction system when engine works with a small load and can limit and guide the reciprocating movement of spring to decrease the abnormal sound generated from the diaphragm type PCV valve and prolong the service life of PCV valve.

Description

technical field [0001] The present invention relates to a PCV valve for an engine crankcase ventilation system. Background technique [0002] In order to solve the problem of the blow-by of the piston in the crankcase, the engine must be equipped with a PCV valve connecting the crankcase and the intake manifold. Most of the existing PCV valves use diaphragm PCV valves, which have a large flow area. Only one ventilation line is needed to introduce the piston blow-by gas in the crankcase into the intake system in time, but because the PCV valve is closed when the engine is idling, and the engine still has a certain amount of piston blow-by gas at this time, when When the air leakage of the piston in the crankcase reaches a certain pressure, the PCV valve will be opened instantaneously. At this time, the air flow passes through the channel with a small cross-section, which is prone to abnormal noise. In addition, due to the frequent opening and closing of the PCV valve, if the...

AI Technical Summary

Problems solved by technology

[0002] In order to solve the problem of the blow-by of the piston in the crankcase, the engine must be equipped with a PCV valve connecting the crankcase and the intake manifold. Most of the existing PCV valves use diaphragm PCV valves, which have a large flow area. Only one ventilation line is needed to introduce the piston blow-by gas in the crankcase into the intake system in time, but because the PCV valve is closed when the engine is idling, and the engine still has a certain amount of piston blow-by gas at this time, when When the air leakage of the piston in the crankcase reaches a certain pressure, the PCV valve will be opened instantaneously. At this time, the air flow passes through the channel with a small cross-section, which is prone to abnormal noise.

In addition, due to the frequent opening and closing of the PCV valve, if the valve is only guided by the spring, it is prone to poor seating or even failure to close normally after a long period of work, resulting in deformation of the diaphragm and spring, and abnormal noise at the same time

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