CN113153490A - Engine crankcase ventilation system, engine and vehicle - Google Patents

Abstract

The invention relates to an engine crankcase ventilation system, an engine and a vehicle, wherein the system comprises an oil-gas separator and a PCV valve, the input end of the oil-gas separator is connected to a crankcase, the gas output end of the oil-gas separator is connected to the PCV valve, the system is characterized by further comprising a solenoid valve and a controller, the output end of the PCV valve is connected to the air inlet end of a combustion chamber through the solenoid valve, a through hole which is conducted when the solenoid valve is opened and closed is arranged in the solenoid valve, and the controller is configured to execute the following steps: and acquiring a vehicle state, judging whether the current vehicle state is an idle speed, if so, closing the electromagnetic valve, otherwise, completely opening the electromagnetic valve. Compared with the prior art, the method has the advantages of improving the effect of the idle working condition on the basis of not changing the ventilation effect of the non-idle working condition, and the like.

Description

Engine crankcase ventilation system, engine and vehicle

Technical Field

The invention relates to a positive ventilation system of an engine crankcase, in particular to a ventilation system of an engine crankcase, an engine and a vehicle.

Background

In order to prevent oil leakage of an engine caused by overhigh air pressure of a crankcase of the engine, a PCV valve is arranged on the crankshaft system of the engine, is usually mechanical at present and is opened and closed according to the air pressure difference between the crankcase and an intake manifold. The PCV valve is open when crankcase air pressure > intake manifold air pressure, and is closed when crankcase air pressure < intake manifold air pressure. During idle conditions, intake manifold air pressure is at a minimum and PCV valve opening is at a maximum.

The crankcase ventilation system is provided with an oil-gas separator, the proportion of gasoline mixed in the crankcase is increased along with the increase of the using mileage of a vehicle, the efficiency of the oil-gas separator is reduced, and engine oil partially mixed with the gasoline enters a combustion chamber through a PCV valve. Under the condition of idling, the fuel injection quantity is reduced when the engine speed is reduced, the opening degree of a PCV (positive crankcase ventilation) valve is the largest, at the moment, the combustion chamber is mixed with gas mixture which is not completely subjected to oil-gas separation, the air-fuel ratio of the engine is influenced, the idling of the engine is unstable, and if the engine is suddenly stopped, the gas mixture enters a catalyst, the temperature of the catalyst is suddenly increased and burnt.

Although some prior arts have attempted to solve the above problems by replacing the mechanical PCV valve with the electronic PCV valve, the opening and closing of the solenoid valve is controlled only according to the crankcase pressure value, and the problems of unstable idling, poor emission, and catalyst ablation caused by the entry of a large amount of oil gas into the combustion chamber at idling cannot be fundamentally solved. And moreover, the pressure of the crankcase is taken from the oil level of the engine, the sensor is difficult to mount at the oil level, and the method for mounting the pressure sensor described in the patent is difficult due to the complicated structure of the crankcase and the difference of pressure values at each position. In addition, since the speed of pressure change is very fast, the electronic PCV valve also has a problem in that the state is frequently switched, and the control effect is reduced.

Disclosure of Invention

The invention aims to provide an engine crankcase ventilation system, an engine and a vehicle, which overcome the technical prejudice that a mechanical PCV valve is replaced by an electronic PCV valve to improve the control flexibility, and the small-flow electromagnetic valve is added on a crankcase ventilation pipeline behind the existing PCV valve, so that on the basis of not influencing the structure of the existing crankcase ventilation system and the effect under the non-idling working condition, the problem of poor effect under the idling working condition of the transmission PCV valve is solved by only using an external signal of whether to idle or not and adopting a simple control logic of opening or closing the electromagnetic valve, and the idle oil consumption can be reduced while effectively reducing the emission of polluted gas to the atmosphere from the crankcase.

The purpose of the invention can be realized by the following technical scheme:

an engine crankcase ventilation system comprising an oil-gas separator and a PCV valve, an input end of the oil-gas separator being connected to a crankcase, and a gas output end of the oil-gas separator being connected to the PCV valve, the system further comprising a solenoid valve and a controller, an output end of the PCV valve being connected to an intake end of a combustion chamber through the solenoid valve, the solenoid valve being provided with a through hole that is open when the solenoid valve is open and closed, the controller being configured to perform the steps of:

and acquiring a vehicle state, judging whether the current vehicle state is an idle speed, if so, controlling the electromagnetic valve to be closed, otherwise, controlling the electromagnetic valve to be fully opened.

The PCV valve is a mechanical PCV valve.

Preferably, the diameter of the through hole is 1-1.5 mm

In some embodiments, the controller is an electronic engine control module.

In other embodiments, a solenoid control unit is connected in parallel with the solenoid valve by a bypass air pipe to replace the solenoid valve. Preferably, the bypass air tube has a diameter of 1-1.5 mm.

Another aspect of the invention provides an engine comprising a crankcase ventilation system as described above.

In still another aspect of the invention, a vehicle is provided, which comprises the engine.

Compared with the prior art, the invention has the following beneficial effects:

1) by adding the small-flow electromagnetic valve on the crankcase ventilation pipeline behind the existing PCV valve, on the basis of not influencing the structure of the existing crankcase ventilation system and the effect under the non-idling working condition, the problem of poor effect under the idling working condition of the traditional PCV valve is solved by only using the external signal of whether to idle or not and adopting the simple control logic of opening or closing the electromagnetic valve, and the idling oil consumption can be reduced while the pollution gas discharged to the atmosphere by the crankcase is effectively reduced.

2) The electromagnetic valve is connected to the electronic control module of the engine, so that the electronic design of the ventilation system can be simplified, an independent controller is omitted, and the cost can be reduced.

Drawings

FIG. 1 is a schematic structural view of a crankcase ventilation system according to an embodiment of the invention;

FIG. 2 is a schematic illustration of an engine system according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a solenoid valve according to an embodiment of the present invention, wherein (a) is a schematic diagram of state 1, (b) is a schematic diagram of state 2, and (c) is a schematic diagram of direction A in (b);

wherein: 1. the oil-gas separator comprises an oil-gas separator, 2, a PCV valve, 3, an electromagnetic valve, 4, a crankcase, 5, a combustion chamber, 6, a supercharger, 7, an air filter, 8, a throttle valve, 9, a vacuum pump, 10, an intercooler, 31, a shell, 32, a turnover motor, 33 and a partition plate.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

An engine crankcase ventilation system, as shown in fig. 1, comprises an oil-gas separator 1 and a PCV valve 2, wherein an input end of the oil-gas separator 1 is connected to a crankcase 4, a gas output end of the oil-gas separator 1 is connected to the PCV valve 2, an output end of the PCV valve 2 is connected to an air inlet end of a combustion chamber 5 through the solenoid valve 3, a through hole which is conducted when the solenoid valve 3 is opened and closed is arranged in the solenoid valve 3, and a controller configured to execute the following steps:

and acquiring the vehicle state, judging whether the current vehicle state is an idle speed, if so, closing the electromagnetic valve 3, otherwise, completely opening the electromagnetic valve 3.

The waste gas of the crankcase 4 without mixing with gasoline enters the combustion chamber 5 under the idling condition, and the risks of unstable combustion, emission deterioration and ablation of a catalyst of the engine caused by the change of the air-fuel ratio of the engine under the idling condition are avoided.

The PCV valve 2 is a mechanical PCV valve 2. By adding the small-flow electromagnetic valve 3 on the ventilation pipeline of the crankcase 4 behind the existing PCV valve 2, on the basis of not influencing the structure of the ventilation system of the existing crankcase and the effect under the non-idling working condition, the problem of poor effect under the idling working condition of the transmission PCV valve 2 is solved by only using the external signal of whether to idle or not and adopting the simple control logic of opening or closing the electromagnetic valve 3, and the idle oil consumption can be reduced while the emission of polluted gas to the atmosphere by the crankcase 4 is effectively reduced.

In addition, the problems of unstable idling, NVH performance reduction and emission deterioration caused by the fact that oil gas containing gasoline is mixed into the crankcase 4 in the combustion chamber 5 under the idling condition by the existing engine crankcase ventilation system device and ECM strategy are solved, the idling speed of the engine needs to be increased, sound-proof vibration-isolating materials are added to the whole automobile, the content of noble metal of a catalytic converter is increased, the oil consumption of the whole automobile and the cost are increased, and the influence of crankshaft waste gas on the performance of the engine and the whole automobile under the idling condition is fundamentally eliminated.

In some embodiments, the controller is an electronic engine control module, and the electromagnetic valve 3 is connected to the electronic engine control module, so that the electronic design of the ventilation system can be simplified, a separate controller is omitted, and the cost can be reduced.

As shown in fig. 2, the above-described crankcase ventilation system is applied to an engine applied to a vehicle, the output of the crankcase ventilation system is behind a throttle valve 8, the output of a combustion chamber 5 is externally discharged through a supercharger 6, and the other output of the supercharger 6 is connected to the throttle valve 8 through an intercooler 10.

Fig. 3 is a schematic structural diagram of a solenoid valve, which includes a housing 31, a turnover motor 32, and a partition 33, and a through hole is formed, so that the through hole is opened even after the solenoid valve is closed. The diameter of the through hole is 1-1.5 mm, and a person skilled in the art can definitely select a proper size so as to meet the oil and gas passing of the crankcase and avoid the emission of polluted gas to the atmosphere from the crankcase. Of course, other configurations may be used, as long as the vias remain conductive when fully closed.

In other embodiments, an electromagnetic control unit obtained by connecting a bypass air pipe and an electromagnetic valve in parallel can be used instead of the electromagnetic valve, which can be realized by using a common electromagnetic valve, but the structure of the existing air passage can be changed, the structure of the transmitter can be influenced, and preferably, the diameter of the bypass air pipe is 1-1.5 mm.

Claims (8)

1. An engine crankcase ventilation system comprising an oil-gas separator and a PCV valve, an input end of the oil-gas separator being connected to a crankcase, and a gas output end of the oil-gas separator being connected to the PCV valve, characterized in that the system further comprises a solenoid valve and a controller, an output end of the PCV valve being connected to an intake end of a combustion chamber through the solenoid valve, the solenoid valve having a through hole therein that is open when the solenoid valve is opened and closed, the controller being configured to perform the steps of:

and acquiring a vehicle state, judging whether the current vehicle state is an idle speed, if so, controlling the electromagnetic valve to be closed, otherwise, controlling the electromagnetic valve to be fully opened.

2. The engine crankcase ventilation system of claim 1, wherein the PCV valve is a mechanical PCV valve.

3. The engine crankcase ventilation system of claim 1, wherein the controller is an engine electronic control module.

4. The engine crankcase ventilation system of claim 1, wherein the through-hole has a diameter of 1-1.5 mm.

5. An engine crankcase ventilation system, comprising an oil-gas separator and a PCV valve, wherein the input end of the oil-gas separator is connected to a crankcase, the gas output end of the oil-gas separator is connected to the PCV valve, the system is characterized by further comprising a solenoid valve, a bypass air pipe and a controller, the bypass air pipe is connected with the solenoid valve in parallel to form a solenoid control unit, the diameter of the bypass air pipe is smaller than that of a pipeline where the solenoid valve is located, the output end of the PCV valve is connected to the air inlet end of a combustion chamber through the solenoid control unit, and the controller is configured to execute the following steps:

and acquiring a vehicle state, judging whether the current vehicle state is an idle speed, if so, controlling the electromagnetic valve to be closed, otherwise, controlling the electromagnetic valve to be fully opened.

6. The engine crankcase ventilation system of claim 5, wherein the bypass air duct has a diameter of 1-1.5 mm.

7. An engine comprising a crankcase ventilation system according to any one of claims 1 to 6.

8. A vehicle comprising the engine of claim 7.

Images