CN204239013U - A kind of engine PCV system - Google Patents

Abstract

The utility model protects an engine crankcase forced ventilation system, which includes a crankcase, a cylinder head, a cylinder head cover, an intake manifold, a supercharger intake pipe, a supercharger, an oil-gas separator, and a ventilation pipeline. Its ventilation pipeline includes the crankcase ventilation 1# pipe connecting the oil-air separator and the intake manifold, the crankcase ventilation 2# pipe connecting the oil-gas separator and the supercharger intake pipe, the crankcase ventilation 1# pipe and the crankcase ventilation pipe. Ventilation 2# pipe integrates 1# one-way valve and 2# one-way valve respectively. The improvement is that a scavenging pipe is connected between the cylinder head cover and the intake pipe of the supercharger, and the scavenging pipe is integrated with a one-way valve of the scavenging pipe. The utility model increases the scavenging function by adding a scavenging pipeline in the ventilation system of the two vent pipe structures of the conventional supercharged gasoline engine, and greatly reduces the white foam generated by the engine in winter when the external environment temperature is low and the load is low. The effective line is blocked and the crankcase ventilation system is ineffective.

Description

Engine crankcase forced ventilation system

technical field

The utility model belongs to the automobile engine technology and relates to a forced ventilation system for an engine crankcase, in particular to a forced ventilation system for a crankcase which is especially suitable for a supercharged gasoline engine.

Background technique

When the engine is working, a part of the combustible mixture and exhaust gas will always escape into the crankcase through the piston ring, and the gasoline vapor condensed into the crankcase will make the engine oil thinner and the performance will be worse. The water vapor and sulfur dioxide contained in the exhaust gas will , has 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 oil will seep from the crankshaft oil seal, crankcase liner, etc. and lose. The oil vapor lost to the atmosphere will increase the pollution of the atmosphere. Therefore, the state stipulates that the engine must be equipped with a crankcase gas purification device, that is, a crankcase ventilation system. The function of the crankcase ventilation system is to:

1. Prevent oil deterioration;

2. Prevent the leakage of seals such as crankshaft oil seal and crankcase gasket;

3. Prevent various oil vapors from polluting the atmosphere.

Any current crankcase ventilation system includes an oil-air separation device, a pressure regulating device and its connecting pipelines. The main function of the oil-gas separation device is to separate the oil and gas (including water vapor, gasoline vapor, etc.) in the crankcase blow-by gas, so that the oil flows back to the oil pan to continue to participate in the cycle, while the gas enters the intake system to participate in combustion. The pressure regulator is used to regulate the pressure in the crankcase to slightly below atmospheric pressure. The above-mentioned oil-gas separation device, pressure regulating device and connecting pipelines are arranged in the cylinder head cover, on the cylinder block or outside the engine body according to the actual situation.

For a supercharged gasoline engine, when running at low load, the vacuum inside the intake manifold behind the supercharger is relatively large; The intake pipe vacuum is relatively large, and the crankcase ventilation system of the supercharged gasoline engine is designed to take advantage of this characteristic. At present, the crankcase forced ventilation system commonly used in supercharged gasoline engines includes crankcase, cylinder head, cylinder head cover, oil-gas separator, intake manifold, supercharger intake pipe, supercharger and connecting oil-gas separator and intake air. The crankcase ventilation 1# pipe of the manifold, the crankcase ventilation 2# pipe connecting the oil-air separator and the supercharger intake pipe, the crankcase ventilation 1# pipe and the crankcase ventilation 2# pipe are respectively integrated with the 1# check valve and 2 # Check valve. The blow-by gas enters the cylinder head cover through the cylinder head from the crankcase, and then enters the oil-air separator, and the separated oil flows back to the crankcase to continue circulation. When the engine is running at a low load, the vacuum of the intake manifold is relatively high, and the gas separated by the oil-gas separator enters the intake manifold through the crankcase ventilation 1# pipe; when the engine is running at a medium and high load, the vacuum in the intake manifold of the supercharger Larger, the gas separated by the oil-gas separator enters the intake pipe of the supercharger through the crankcase ventilation 2# pipe, and then enters the intake manifold after being pressurized by the supercharger.

In the actual use process, when the supercharged gasoline engine with the structure of two ventilation pipes is running at low load, the blow-by gas is less, the pressure in the crankcase is low, the flow of the blow-by gas is not smooth, and the blow-by gas stays in the winding system for a longer time long. Therefore, in winter (especially in the north), the water vapor and gasoline vapor in the blow-by gas of the crankcase will condense in the above-mentioned devices and pipelines, and mix with the engine oil to form white foam. road, causing 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.

Utility model content

The purpose of the utility model is to provide a forced ventilation system for the engine crankcase in view of the problems existing in the prior art. A scavenging pipeline is added to the ventilation system of the conventional supercharged gasoline engine with two ventilation pipes to increase the scavenging function and greatly Reduces the white foam generated by the engine when the external ambient temperature is low and the engine is operated at low load in winter.

The technical scheme of the utility model is as follows:

A crankcase forced ventilation system for an engine includes a crankcase, a cylinder head, a cylinder head cover, an intake manifold, a supercharger intake pipe, a supercharger, an oil-gas separator, a ventilation pipeline, and the like. The oil-air separator integrates the pressure regulator PRV valve. The ventilation pipeline includes the crankcase ventilation 1# pipe connecting the oil-air separator and the intake manifold, the crankcase ventilation 2# pipe connecting the oil-gas separator and the supercharger intake pipe, the crankcase ventilation 1# pipe and the crankcase ventilation pipe The 2# pipe integrates the 1# one-way valve and the 2# one-way valve respectively. The improvement is that a scavenging pipe is connected between the cylinder head cover and the intake pipe of the supercharger, and the scavenging pipe is integrated with a one-way valve of the scavenging pipe.

The blow-by gas generated during the operation of the engine enters the cylinder head cover from the crankcase through the cylinder head, enters the oil-air separator from the cylinder head cover, and is separated by the oil-air separator to form engine oil and mixed gas. The engine oil flows back into the crankcase from the oil-air separator and continues to participate in the cycle. When the engine is running at a low load, the pressure of the intake manifold is low, and the gas separated by the oil-gas separator enters the intake manifold through the curved 1# pipe, and finally enters the cylinder to participate in combustion; when the engine is running at a medium and high load, the pressure of the intake manifold Increase, Qutong 1# pipe 1# one-way valve is closed, the gas separated by the oil-gas separator enters the intake pipe of the supercharger through the Qutong 2# pipe, and then enters the intake manifold after being compressed by the supercharger, and finally into the cylinder to participate in combustion.

At the same time, when the engine is running at low load, there is less blow-by gas in the crankcase, the pressure in the crankcase is small, and the pressure in the intake pipe of the supercharger is greater than the pressure in the cylinder head cover. When the pressure difference is greater than the value set by the check valve of the scavenging pipe , the one-way valve of the scavenging pipe is opened, and the fresh air enters the cylinder head cover from the intake pipe of the supercharger. Fresh air enters the cylinder head cover, which increases the pressure of the crankcase, accelerates the blow-by gas entering the oil-gas separator, and reduces the residence time of the blow-by gas mixture in the tortuous system, thereby reducing the condensation of water vapor at low temperature and reducing white foam Formation.

The utility model increases the scavenging function by adding a scavenging pipeline to the ventilation system of the two vent pipe structures of the conventional supercharged gasoline engine, and greatly reduces the white foam generated by the engine in winter when the external environment temperature is low and the load is low. The effective line is blocked and the crankcase ventilation system is ineffective.

Description of drawings

Fig. 1 is a schematic diagram of crankcase forced ventilation system;

Figure 2 is a schematic diagram of the main structure of the crankcase ventilation system;

Fig. 3 is a schematic diagram of the installation position of the oil-gas separator;

Fig. 4 is a schematic diagram of the connection of the curved pipeline;

Fig. 5 is a structural schematic diagram of a supercharger intake pipe and a supercharger;

Figure 6 is a schematic diagram of the connection between the scavenging pipe and the cylinder head cover.

In the figure, 1- crankcase, 2- cylinder head, 3- cylinder head cover, 4- intake manifold, 5- crankcase ventilation 1# pipe, 6- crankcase ventilation 2# pipe, 7- scavenging pipe, 8 -Scavenging pipe one-way valve, 9-oil-air separator, 10-1# one-way valve, 11-2# one-way valve, 12-PRV valve, 13-supercharger intake pipe, 14-supercharger.

Detailed ways

The structure of the present utility model is further described in detail below in conjunction with accompanying drawing:

1 and 2, the engine crankcase forced ventilation system includes a crankcase 1, a cylinder head 2, a cylinder head cover 3, an intake manifold 4, a supercharger intake pipe 13, a supercharger 14, an oil-gas separator 9 and Ventilation pipes etc.

Crankcase 1, cylinder head 2 and cylinder head cover 3 are connected together, intake manifold 4 is installed on the cylinder head 2, engine blow-by gas enters cylinder head 2 from crankcase 1, then enters in cylinder head cover 3. The pressure regulator PRV valve 12 is integrated on the oil-gas separator 9 . The ventilation pipeline includes the crankcase ventilation 1# pipe 5 connecting the oil-air separator and the intake manifold, the crankcase ventilation 2# pipe 6 connecting the oil-air separator and the intake pipe of the supercharger, and the cylinder head cover and the supercharger. The scavenging pipe 7 integrates the 1# check valve 10 and the 1# check valve 11 in the crankcase ventilation 1# pipe and the crankcase ventilation 2# pipe respectively, and the scavenging pipe check valve 8 is arranged on the scavenging pipe.

3-6, the blow-by gas in the cylinder head cover 3 enters the oil-gas separator 9 installed on it for separation, the separated engine oil flows back into the crankcase 1, and the separated gas passes through the crankcase ventilation 1 respectively. #pipe 5 and crankcase ventilation 2#pipe 6 enter the intake manifold 4 and supercharger intake pipe 13. When the engine is running at low load, the vacuum in the intake manifold 4 is relatively large, the 1# check valve 10 is opened, the 2# check valve 11 is closed, and the gas separated by the oil-gas separator 9 passes through the crankcase ventilation 1# pipe 5 Enter the intake manifold (4); when the engine is running at medium and high loads, the vacuum in the intake pipe 13 of the supercharger is relatively large, the 2# check valve 11 is opened, the 1# check valve 10 is closed, and the oil and gas separator 9 is separated The gas enters the supercharger intake pipe 13 through the crankcase ventilation 2# pipe 6, and then enters the supercharger 14 for compression. At the same time, when the engine is running at low load, the blow-by gas in the crankcase 1 is less, the pressure is lower, the pressure in the cylinder head cover 3 is also low, and the pressure in the intake pipe 13 of the supercharger is relatively high. When the pressure difference of the compressor intake pipe 13 reaches the set value of the one-way valve 8 of the scavenging pipe, the one-way valve 8 of the scavenging pipe is opened, and fresh air enters the cylinder head cover 3 through the scavenging pipe 7 for scavenging. After the fresh air enters, the flow speed of the blow-by gas is accelerated, the blow-by gas can be separated well, and the residence time is shortened, thus reducing the formation of white foam.

Claims (1)

1. A forced ventilation system for engine crankcase, comprising crankcase, cylinder head, cylinder head cover, intake manifold, supercharger intake pipe, supercharger, oil-gas separator and ventilation pipeline, said oil-gas separator The pressure regulating device PRV valve is integrated, and the ventilation pipeline includes the crankcase ventilation 1# pipe connecting the oil-gas separator and the intake manifold, the crankcase ventilation 2# pipe connecting the oil-gas separator and the intake pipe of the supercharger, and the crankcase ventilation pipe The 1# pipe and the crankcase ventilation 2# pipe are respectively integrated with the 1# check valve and the 2# check valve; the feature is that the air scavenging pipe is connected between the cylinder head cover and the intake pipe of the supercharger, and the air scavenging pipe is arranged on the air scavenging pipe one-way valve.