A crankcase ventilation system, method, and vehicle

Abstract

The present application relates to the field of vehicles, in particular to a crankcase ventilation system, method and vehicle. The crankcase ventilation system comprises a crankcase, an oil-gas separator and a pressure regulating assembly. The pressure regulating assembly comprises a vacuum pump, an air path electromagnetic valve and an air inlet pipe connected in sequence. The pressure regulating assembly is used to regulate the negative pressure of the crankcase, so that the crankcase has a larger negative pressure. Under normal working conditions of the engine, the air path electromagnetic valve is closed, and only the original structure of the crankcase works. Under the post-processing heating working condition of cold start of the engine and other working conditions with larger throttle opening, in order to avoid the harm caused by the larger negative pressure of the air inlet cavity, the pressure regulating assembly works. At this time, the air path electromagnetic valve is controlled to connect the air path between the crankcase and the air inlet pipe, and the vacuum pump is controlled to work, so as to control the pressure in the crankcase, realize that the pressure in the crankcase is still smaller than the in-cylinder pressure, avoid the penetration of engine oil into the cylinder, cause the engine oil to burn, and ensure the sealing performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicles, in particular to a crankcase ventilation system, method and vehicle. BACKGROUND

[0002] When the engine is working, the high-temperature and high-pressure gas in the combustion chamber will enter the crankcase with the piston ring. In order to prevent the sealing of the crankcase from being damaged and reduce the influence on the performance of the oil, the gas that enters the crankcase needs to be discharged in time. With the increasingly stringent emission requirements, crankcase ventilation also needs to introduce emission limit value control. The most common scene here is to introduce the remaining exhaust gas into the inlet end of the supercharger through the oil-gas separator and the pipeline, and then enter the cylinder again with fresh air for combustion to avoid polluting the environment.

[0003] In order to achieve the purpose of improving the exhaust temperature, achieving heating aftertreatment and improving the conversion efficiency, the method of increasing fuel injection and reducing intake air quantity is usually adopted. However, the current problem of reducing intake air quantity is that the negative pressure of the engine intake cavity is very low. In order to improve the exhaust temperature, the engine intake cavity pressure may be lower than 65kPa. In order to realize the engine aftertreatment heating working condition, the negative pressure needs to be further reduced. However, the reduction of the negative pressure in the engine intake cavity will cause the sealing of the intake cavity to be weakened, and the oil will seep into the intake cavity or the cylinder, which will affect the reliability of the engine.

[0004] Therefore, there is an urgent need for a crankcase ventilation system to solve the above technical problems. SUMMARY

[0005] The purpose of the present application is to provide a crankcase ventilation system, method and vehicle, which can avoid the weakening of the sealing caused by the reduction of the negative pressure in the engine intake cavity when the engine is in the aftertreatment heating working condition.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, a crankcase ventilation system is provided, comprising:

[0008] a crankcase;

[0009] an oil-gas separator, the inlet of the oil-gas separator being in communication with the outlet of the crankcase, the liquid outlet of the oil-gas separator being connected to the oil pan, the oil-gas separator having two gas outlets, one of the gas outlets of the oil-gas separator being in communication with at least the atmosphere or the engine intake pipe;

[0010] The pressure regulating assembly comprises a vacuum pump, a gas circuit electromagnetic valve and an air inlet pipe connected in sequence, the air inlet of the vacuum pump is connected with another air outlet of the oil-gas separator, the air inlet pipe has a first air inlet and a second air inlet, the air outlet of the air inlet pipe is connected with the air inlet cavity of the engine, the first air inlet is connected with the gas circuit electromagnetic valve, the second air inlet is connected with the engine air inlet pipe, and the pressure regulating assembly is used for regulating the pressure in the crankcase so that the pressure in the crankcase is less than the pressure in the air inlet cavity of the engine.

[0011] As a preferred technical scheme of the crankcase ventilation system, the pressure regulating assembly further comprises a heating device, and the heating device is used for heating the gas circuit electromagnetic valve and the vacuum pump.

[0012] As a preferred technical scheme of the crankcase ventilation system, the heating device is connected with the engine cooling water pipeline, the gas circuit electromagnetic valve and the vacuum pump are both provided with a cooling water channel, and the heating device is in communication with the cooling water channel.

[0013] As a preferred technical scheme of the crankcase ventilation system, the pressure regulating assembly further comprises a pressure sensor, and the pressure sensor is used for detecting the pressure in the crankcase.

[0014] As a preferred technical scheme of the crankcase ventilation system, the pressure regulating assembly further comprises a pressure controller, and the pressure controller is at least in communication connection with the pressure sensor, the vacuum pump and the gas circuit electromagnetic valve.

[0015] As a preferred technical scheme of the crankcase ventilation system, the crankcase ventilation system further comprises a throttle valve, the engine air inlet pipe is connected with the air inlet of the throttle valve, and the air outlet of the throttle valve is in communication with the second air inlet of the air inlet pipe.

[0016] As a preferred technical scheme of the crankcase ventilation system, the crankcase ventilation system further comprises a supercharger and a ventilation pipeline, the supercharger is arranged between the engine air inlet pipe and the throttle valve to communicate the engine air inlet pipe and the throttle valve, the ventilation pipeline is in communication with one of the air outlets of the oil-gas separator and the air outlet of the supercharger, and the ventilation pipeline is also in communication with the engine air inlet pipe; or,

[0017] The crankcase ventilation system further comprises a one-way valve and a ventilation pipeline, the air inlet of the one-way valve is connected with one of the air outlets of the oil-gas separator, the air outlet of the one-way valve is in communication with the air inlet of the ventilation pipeline, and the air outlet of the ventilation pipeline is in communication with the atmosphere or the engine air inlet pipe.

[0018] In a second aspect, a method for controlling a crankcase ventilation system is provided, which is applied to the crankcase ventilation system according to any one of the preceding aspects, and comprises the following steps:

[0019] When the engine is in the post-processing heating working condition, the pressure in the crankcase and the pressure in the intake cavity of the engine are obtained, and the difference between the pressure in the intake cavity of the engine and the pressure in the crankcase is obtained;

[0020] The pressure regulating assembly is controlled according to the difference.

[0021] As a preferred technical solution of the method for controlling the crankcase ventilation system, the controlling of the pressure regulating assembly according to the difference comprises:

[0022] When the difference is less than or equal to a first preset difference, the vacuum pump is started, and the gas path electromagnetic valve between the vacuum pump and the intake connecting pipe is opened, the vacuum pump extracts the crankcase gas into the intake cavity, until the difference is a second preset difference, the vacuum pump is closed, and the gas path electromagnetic valve is closed.

[0023] When the difference is greater than or equal to a third preset difference, the gas path electromagnetic valve is opened, and the vacuum pump is not started, until the difference is the second preset difference, and the gas path electromagnetic valve is closed.

[0024] Wherein, the first preset difference < the second preset difference < the third preset difference.

[0025] In a third aspect, a vehicle is provided, which comprises the crankcase ventilation system according to any one of the preceding aspects.

[0026] The present application has at least the following advantages:

[0027] The crankcase ventilation system and the vehicle provided by the present application have the following advantages: the crankcase ventilation system comprises a crankcase, an oil-gas separator and a pressure regulating assembly, the pressure regulating assembly comprises a vacuum pump, a gas path electromagnetic valve and an intake connecting pipe connected in sequence, the pressure regulating assembly is used for regulating the negative pressure of the crankcase, so that the crankcase has a larger negative pressure, the gas path electromagnetic valve is closed under normal working conditions of the engine, and only the original structure of the crankcase works; under the post-processing heating working condition of cold start of the engine and other working conditions with a larger throttle opening, the pressure regulating assembly works to avoid the harm caused by a larger negative pressure in the intake cavity, at this time, the gas path electromagnetic valve is controlled to connect the gas path between the crankcase and the intake connecting pipe, and the vacuum pump is controlled to work, so as to control the pressure in the crankcase to decrease and the pressure in the intake cavity to increase, the pressure in the crankcase is always less than the in-cylinder pressure, the oil is prevented from seeping into the cylinder to cause oil burning, and the sealing property is ensured.

[0028] The method provided by the application, in order to avoid the harm caused by the large negative pressure of the intake cavity, the differential pressure between the pressure of the engine intake cavity and the pressure in the crankcase is obtained to control the operation of the air path electromagnetic valve and the vacuum pump, so as to control the pressure of the crankcase, and the pressure of the crankcase is still less than the pressure in the cylinder (i.e. the pressure of the intake cavity), so as to avoid the penetration of engine oil into the cylinder, to prevent the engine oil from being burned, and to ensure the sealing performance. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the description of the embodiments of the application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by the person skilled in the art according to the contents of the embodiments of the application and the drawings without any creative effort.

[0030] Figure 1 The block diagram of the closed circulation crankcase ventilation system with a supercharger rear intake provided by the embodiments of the application is shown in the figure.

[0031] Figure 2 The block diagram of the closed circulation crankcase ventilation system without a supercharger rear intake provided by the embodiments of the application is shown in the figure.

[0032] Figure 3 The block diagram of the open circulation crankcase ventilation system provided by the embodiments of the application is shown in the figure.

[0033] Figure 4 The flow chart of the control method of the crankcase ventilation system provided by the embodiments of the application is shown in the figure.

[0034] In the figure:

[0035] 1, crankcase; 2, oil-gas separator; 3, vacuum pump; 4, air path electromagnetic valve; 5, intake connection pipe; 6, engine intake pipe; 7, heating device; 8, pressure controller; 9, pressure sensor; 10, throttle valve; 11, supercharger; 12, ventilation pipeline; 13, one-way valve; 15, cylinder; 16, intake cavity; 17, external atmosphere. DETAILED DESCRIPTION

[0036] The application will be further described in detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the application, but not to limit the application. In addition, it should be noted that, in order to facilitate the description, only the parts related to the application are shown in the drawings, but not all the structures.

[0037] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0038] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0040] like Figures 1-3 As shown, the crankcase ventilation system includes a crankcase 1, an oil-gas separator 2 and a pressure regulating assembly, wherein the inlet of the oil-gas separator 2 is connected to the outlet of the crankcase 1, the inlet of the crankcase 1 is connected to the cylinder 15, the liquid outlet of the oil-gas separator 2 is connected to the oil pan, the oil-gas separator 2 has two air outlets, one of which is connected to the outside atmosphere 17 or the engine intake pipe 6; the pressure regulating assembly includes a vacuum pump 3, an air circuit solenoid valve 4 and an intake pipe 5 connected in sequence, ... The air inlet of the pump 3 is connected to the other air outlet of the oil-gas separator 2. The air intake pipe 5 has a first air inlet and a second air inlet. The air outlet of the air intake pipe 5 is connected to the air intake chamber 16 of the engine. The first air inlet is connected to the air circuit solenoid valve 4, and the second air inlet is connected to the engine intake pipe 6. The air inlet of the vacuum pump 3 is connected to the other air outlet of the oil-gas separator 2. The pressure regulating assembly is used to adjust the pressure in the crankcase 1 so that the pressure in the crankcase 1 is lower than the pressure in the air intake chamber 16 of the engine.

[0041] The crankcase ventilation system provided by the embodiment comprises a pressure regulating assembly, which is used to regulate the negative pressure of the crankcase 1, so that the crankcase 1 has a larger negative pressure. Under normal working conditions of the engine, the air path electromagnetic valve 4 is closed, and only the original structure of the crankcase 1 works. Under the working conditions of the post-processing heating condition of the cold start of the engine and other large throttle opening conditions, in order to avoid the harm caused by the large negative pressure of the intake cavity 16, the pressure regulating assembly works. At this time, the control air path electromagnetic valve 4 connects the air path of the crankcase 1 and the intake pipe 5, and controls the vacuum pump 3 to work, so as to control the pressure in the crankcase 1 to decrease and the pressure in the intake cavity 16 to increase, so that the pressure in the crankcase 1 is still smaller than the pressure in the cylinder (i.e. the intake cavity 16), avoiding the oil from seeping into the cylinder, causing the engine oil to burn, and ensuring the sealing performance.

[0042] By arranging the pressure regulating assembly, the flexible control of the larger negative pressure of the crankcase 1 can be realized, so that the heat management (the post-processing heating condition of the cold start of the engine) of the lower intake negative pressure can be realized without the oil seeping into the cylinder, which helps to help the post-processing temperature rise and maintain the post-processing temperature during the long-term low load, ensures the catalytic conversion efficiency, and reduces the pollutant emission.

[0043] Since the added pressure regulating assembly mainly works under the working conditions of the post-processing heating condition of the cold start of the engine and the continuous low load, at this time, the gas temperature in the crankcase 1 is low, and there is a risk of icing in winter. Therefore, in some embodiments, the pressure regulating assembly further comprises a heating device 7, which is used to heat the air path electromagnetic valve 4 and the vacuum pump 3. In this way, the heating device 7 can be started to work when the pressure regulating assembly works, so as to ensure the normal work of the air path electromagnetic valve 4 and the vacuum pump 3, and avoid the blockage of the air path electromagnetic valve 4 and the vacuum pump 3 due to icing.

[0044] For example, the heating device 7 is connected with the engine cooling water pipeline, the air path electromagnetic valve 4 and the vacuum pump 3 are both provided with a cooling water channel, and the heating device 7 communicates with the cooling water channel, so that the heating device 7 can introduce the engine cooling water into the cooling water channel to heat the air path electromagnetic valve 4 and the vacuum pump 3. By heating the pressure regulating assembly and the pipeline by the engine cooling water, the icing of the pressure regulating assembly and the pipeline is avoided, and the heating device 7 does not need to be controlled. It should be noted that heating the pressure regulating assembly and the pipeline under the post-processing heating condition of the cold start of the engine will cause the intake temperature to rise slightly, but has no effect on the post-processing heating condition of the cold start of the engine.

[0045] In some embodiments, in order to obtain the pressure in the crankcase 1, the crankcase ventilation system further comprises a pressure sensor 9, which is used to detect the pressure in the crankcase 1.

[0046] In some embodiments, in order to be able to control the pressure regulating assembly according to the pressure in the crankcase 1 and the pressure in the intake cavity 16, the crankcase ventilation system further comprises a pressure controller 8, which is in communication with at least the pressure sensor 9, the vacuum pump 3 and the air path electromagnetic valve 4. The pressure controller 8 controls the vacuum pump 3 and the air path electromagnetic valve 4 to work after obtaining the pressure of the crankcase 1 detected by the pressure sensor 9, or the pressure controller 8 controls the air path electromagnetic valve 4 to work.

[0047] In some embodiments, the crankcase ventilation system further comprises an engine intake pipe 6 and a throttle valve 10, the intake port of the engine intake pipe 6 is connected to the throttle valve 10, and the exhaust port of the throttle valve 10 is in communication with the second intake port of the intake connection pipe 5. The engine intake pipe 6 has an air filter to filter the gas.

[0048] In some embodiments, as shown in Figure 1 , the crankcase ventilation system further comprises a supercharger 11 and a ventilation pipeline 12, the supercharger 11 is arranged between the engine intake pipe 6 and the throttle valve 10 to communicate the engine intake pipe 6 and the throttle valve 10, the ventilation pipeline 12 is in communication with one of the exhaust ports of the oil-gas separator 2 and the exhaust port of the supercharger 11 respectively, and the ventilation pipeline 12 is also in communication with the engine intake pipe 6. In this embodiment, the engine is a diesel engine, and other structures are slightly different for different models of diesel engines and ventilation routes. For example, the crankcase ventilation system is a closed circulation structure with the supercharger 11 taking gas after the supercharger 11, that is, the structure after the oil-gas separator 2 generally includes a one-way valve 13, a gas guide pipe taking gas after the supercharger 11, a Venturi device using high flow rate of gas flow for guiding, and an exhaust pipe exhausting to the supercharger 11.

[0049] In some embodiments, as shown in Figure 2 and Figure 3 , the crankcase ventilation system further comprises a one-way valve 13 and a ventilation pipeline 12, the intake port of the one-way valve 13 is connected to one of the exhaust ports of the oil-gas separator 2, the exhaust port of the one-way valve 13 is in communication with the intake port of the ventilation pipeline 12, and the exhaust port of the ventilation pipeline 12 is in communication with the atmosphere 17 or the engine intake pipe 6. For example, the crankcase ventilation system is a closed circulation structure without the supercharger 11 taking gas after the supercharger 11, and generally only has an exhaust pipeline connected to the supercharger 11 after the oil-gas separator 2; when the crankcase ventilation system is an open circulation, there is also only one ventilation pipeline 12 in communication with the atmosphere after the oil-gas separator 2.

[0050] As shown in Figure 2 , for the structure without taking gas after the supercharger, since the crankcase ventilation system does not have the one-way valve 13, the crankcase 1 will suck air from the atmosphere or before the supercharger 11 when the negative pressure is large, which causes the pressure to be unable to drop, and thus a one-way valve 13 needs to be added to the second exhaust port of the oil-gas separator 2.

[0051] The application provides a crankcase ventilation system control method, which is applied to a crankcase ventilation system. Figure 4 As shown in the figure, the crankcase ventilation system control method comprises the following steps:

[0052] S101, obtaining the pressure in the crankcase 1 and the pressure of the engine intake cavity 16 when the engine is in the post-processing heating working condition, obtaining the difference between the pressure of the engine intake cavity 16 and the pressure in the crankcase 1;

[0053] S102, controlling the pressure adjusting assembly to work according to the difference.

[0054] In the post-processing heating working condition of the cold start of the engine and other working conditions with a large throttle opening, in order to avoid the harm caused by the large negative pressure of the intake cavity 16, the difference pressure between the pressure of the engine intake cavity 16 and the pressure in the crankcase 1 is obtained to control the vacuum pump 3 and the air path electromagnetic valve 4 to work, so as to control the pressure in the crankcase 1, so that the pressure in the crankcase 1 is still less than the pressure in the cylinder (i.e. the pressure in the intake cavity 16), the oil is prevented from seeping into the cylinder, the oil is prevented from being burned, and the sealing property is ensured.

[0055] In some embodiments, controlling the pressure adjusting assembly to work according to the difference comprises:

[0056] S1021, when the difference is less than or equal to the first preset difference, the vacuum pump 3 is started, the air path electromagnetic valve 4 between the vacuum pump 3 and the intake pipe 5 is opened, the vacuum pump 3 extracts the gas in the crankcase 1 into the intake cavity 16, and when the difference is the second preset difference, the vacuum pump 3 is closed and the air path electromagnetic valve 4 is closed;

[0057] S1022, when the difference is greater than or equal to the third preset difference, the air path electromagnetic valve 4 is opened and the vacuum pump 3 is not started, and when the difference is the second preset difference, the air path electromagnetic valve 4 is closed.

[0058] The first preset difference < the second preset difference < the third preset difference.

[0059] The pressure controller 8 stores the target value of the difference between the pressure in the crankcase 1 and the pressure in the intake cavity 16 under each rotating speed and torque working condition, and the preset difference is three, which are the first preset difference, the second preset difference and the third preset difference, wherein the first preset difference is the lower limit value, the second preset difference is the maintenance value, the third preset difference is the upper limit value, and the first preset difference < the second preset difference < the third preset difference.

[0060] For example, the first preset difference is 3kPa, the second preset difference is 9kPa, and the third preset difference is 15kPa. The control state of the pressure controller 8 has three, which are increasing the pressure difference, reducing the pressure difference, and maintaining the pressure difference. When the pressure difference is increased, the vacuum pump 3 is started, and the air path electromagnetic valve 4 between the vacuum pump 3 and the air inlet pipe 5 is opened. The vacuum pump 3 extracts the gas in the crankcase 1 into the air inlet cavity 16 to increase the pressure difference. When the pressure difference is reduced, the air path electromagnetic valve 4 is opened, but the vacuum pump 3 is not started. The air inlet pipe 5 and the crankcase 1 push the air into the crankcase 1 to reduce the pressure difference. When the pressure difference is maintained, the vacuum pump 3 is stopped and the air path electromagnetic valve 4 is closed. The gas in the crankcase 1 cannot be discharged, and the pressure difference is maintained. When the crankcase 1 is normally started and works, the pressure difference between the air inlet cavity 16 and the crankcase 1 is less than 3kPa (the first preset difference), and the pressure difference is increased. At this time, the vacuum pump 3 and the air path electromagnetic valve 4 are opened, and the gas in the crankcase 1 is transported to the air inlet pipe 5. When the pressure difference between the air inlet pressure and the crankcase 1 reaches 9kPa (the second preset difference), it returns to the pressure difference maintaining state. At this time, the air path electromagnetic valve 4 and the vacuum pump 3 are closed. Due to the existence of the one-way valve 13, the normal crankcase ventilation structure cannot transport the gas to the crankcase 1, and the pressure of the crankcase 1 is basically maintained. When the pressure difference between the air inlet pressure and the crankcase 1 is too large and exceeds 15kPa (the third preset difference), the pressure difference is reduced. At this time, the air path electromagnetic valve 4 is opened, and the gas enters the crankcase 1 from the air inlet pipe 5. When it is less than 9kPa (the second preset difference), it jumps to the pressure difference maintaining state, and the air path electromagnetic valve 4 is closed.

[0061] The embodiment of the present application provides a vehicle comprising the crankcase ventilation system provided by the present application.

[0062] Since the vehicle comprises the crankcase ventilation system, the crankcase ventilation system comprises a pressure regulating assembly for regulating the negative pressure of the crankcase 1, so that the crankcase 1 has a larger negative pressure. In the normal working condition of the engine, the air path electromagnetic valve 4 is closed, and only the original structure of the crankcase 1 works. In the post-processing heating working condition of the cold start of the engine and other conditions with a larger opening degree of the throttle valve 10, in order to avoid the harm caused by the large negative pressure of the air inlet cavity 16, the pressure regulating assembly works. At this time, the air path electromagnetic valve 4 is connected to the air path between the crankcase 1 and the air inlet pipe 5, and the vacuum pump 3 is controlled to work to control the pressure of the crankcase 1, so that the pressure of the crankcase 1 is still less than the pressure in the cylinder (i.e. the pressure in the air inlet cavity 16), avoiding the penetration of engine oil into the cylinder, causing the engine oil to burn, and ensuring the sealing property.

[0063] Since the crankcase ventilation system is included, the vehicle of the embodiment of the present application has all the advantages and beneficial effects of the above-mentioned embodiments, which will not be repeated here.

[0064] Compared with the prior art, the benefits of the present application are:

[0065] (1) The present application realizes the negative pressure of the crankcase 1 relative to the intake cavity 16 in the post-processing heating working condition of the engine cold start by increasing the vacuum pump 3 and the air path electromagnetic valve 4, and controlling the crankcase 1 to realize a larger negative pressure mode, thereby avoiding the problem of burning oil caused by the penetration of engine oil into the cylinder in the post-processing heating working condition of the engine cold start.

[0066] (2) On the basis of not affecting the crankcase ventilation system, a pressure regulating assembly is added, and the pressure difference between the crankcase 1 and the intake cavity 16 can be controlled according to the preset value in the post-processing heating working condition of the engine cold start, and the heating device 7 is set to avoid icing in winter.

[0067] In addition, the above are only preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A crankcase ventilation system, characterized in that: include: Crankcase (1); An oil-gas separator (2), wherein the inlet of the oil-gas separator (2) is connected to the outlet of the crankcase (1), the liquid outlet of the oil-gas separator (2) is connected to the oil pan, and the oil-gas separator (2) has two gas outlets, one of which is connected to at least the outside atmosphere (17) or the engine intake pipe (6); A pressure regulating assembly comprises a vacuum pump (3), an air circuit solenoid valve (4) and an air intake pipe (5) connected in sequence, wherein the air intake of the vacuum pump (3) is connected to another air outlet of the oil-gas separator (2), the air intake pipe (5) has a first air intake and a second air intake, the air outlet of the air intake pipe (5) is connected to an air intake chamber (16) of an engine, the first air intake is connected to the air circuit solenoid valve (4), and the second air intake is connected to an air intake pipe (6) of the engine, and the pressure regulating assembly is used to regulate the pressure in the crankcase (1) so that the pressure in the crankcase (1) is lower than the pressure in the air intake chamber (16) of the engine.

2. The crankcase ventilation system according to claim 1, characterized in that The pressure regulating assembly further comprises a heating device (7), and the heating device (7) is used to heat the gas circuit solenoid valve (4) and the vacuum pump (3).

3. The crankcase ventilation system according to claim 2, characterized in that The heating device (7) is connected to the engine cooling water pipeline, the gas circuit solenoid valve (4) and the vacuum pump (3) are both provided with cooling water channels, and the heating device (7) is in communication with the cooling water channels.

4. The crankcase ventilation system according to claim 1, wherein: It also includes a pressure sensor (9), which is used to detect the pressure in the crankcase (1).

5. The crankcase ventilation system according to claim 4, characterized in that It also includes a pressure controller, which is communicatively connected to at least the pressure sensor (9), the vacuum pump (3) and the gas circuit solenoid valve (4).

6. The crankcase ventilation system according to claim 1, wherein: The crankcase ventilation system further comprises a throttle valve (10), the engine intake pipe (6) is connected to the air inlet of the throttle valve (10), and the air outlet of the throttle valve (10) is communicated with the second air inlet of the intake pipe (5).

7. The crankcase ventilation system according to claim 6, characterized in that The crankcase ventilation system further comprises a supercharger (11) and a ventilation line (12), wherein the supercharger (11) is arranged between the engine air intake pipe (6) and the throttle valve (10) to connect the engine air intake pipe (6) and the throttle valve (10), and the ventilation line (12) is respectively connected to one of the air outlets of the oil-gas separator (2) and the air outlet of the supercharger (11), and the ventilation line (12) is also connected to the engine air intake pipe (6); or, The crankcase ventilation system further comprises a one-way valve (13) and a ventilation pipeline (12), wherein the air inlet of the one-way valve (13) is connected to one of the outlets of the oil-gas separator (2), the air outlet of the one-way valve (13) is communicated with the air inlet of the ventilation pipeline (12), and the air outlet of the ventilation pipeline (12) is communicated with the outside atmosphere (17) or the engine intake pipe (6).

8. A crankcase ventilation system control method, characterized in that: Applied to the crankcase ventilation system according to any one of claims 1 to 7, the crankcase ventilation system control method comprises the following steps: When the engine is in a post-treatment heating state, the pressure in the crankcase (1) and the pressure in the intake chamber (16) of the engine are obtained, and the difference between the pressure in the intake chamber (16) of the engine and the pressure in the crankcase (1) is obtained; The pressure regulating component operates according to the differential control.

9. The crankcase ventilation system control method according to claim 8, characterized in that: The work of the pressure regulating component based on the differential control includes: When the difference is less than or equal to a first preset difference, the vacuum pump (3) is started, and the gas circuit solenoid valve (4) between the vacuum pump (3) and the intake pipe (5) is opened, and the vacuum pump (3) extracts gas from the crankcase (1) into the intake chamber (16), until the difference reaches a second preset difference, the vacuum pump (3) is turned off, and the gas circuit solenoid valve (4) is closed; When the difference is greater than or equal to a third preset difference, the gas circuit solenoid valve (4) is opened and the vacuum pump (3) is not started until the difference reaches a second preset difference, and the gas circuit solenoid valve (4) is closed; The first preset difference is less than the second preset difference and less than the third preset difference.

10. A vehicle, characterized in that: A crankcase ventilation system comprising the crankcase ventilation system according to any one of claims 1 to 7.

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