Engine crankcase ventilation system and vehicle

Abstract

This application discloses an engine crankcase ventilation system and a vehicle, relating to the field of engine technology. The engine crankcase ventilation system includes an intake pipe, a sealed chamber, a first gas passage, and a second gas passage. The intake pipe is connected to the engine's combustion chamber. The sealed chamber is disposed on the engine's valve cover and is connected to the intake pipe, and is also disconnectably connected to the engine's crankcase. Both the first and second gas passages are disposed on the engine cylinders, wherein the first gas passage disconnectably connects the combustion chamber and the crankcase, and the second gas passage disconnectably connects the sealed chamber and the crankcase. The engine crankcase ventilation system and vehicle disclosed in this application reduce additional space occupation, while also being low in cost and highly reliable.

Description

Technical Field

[0001] This application relates to the field of automotive engine technology, specifically to an engine crankcase ventilation system and a vehicle. Background Technology

[0002] During engine operation, high-pressure exhaust gases from the combustion chamber may seep into the crankcase. These gases can cause problems such as oil deterioration, sludge buildup, and other issues. The engine crankcase ventilation system introduces fresh air into the crankcase (i.e., crankcase air supply) and then re-extracts the air-fuel mixture from the crankcase to the intake system for combustion, thus resolving these problems.

[0003] In related technologies, crankcase air replenishment in engines typically involves connecting an additional air replenishment line between the crankcase and the intake manifold; this replenishment line is an external line. However, this method of pipe arrangement requires a certain amount of space, is costly, and has poor reliability. Summary of the Invention

[0004] In view of this, this application provides an engine crankcase ventilation system and vehicle that can reduce additional space occupation, while being low in cost and highly reliable.

[0005] The specific technical solution adopted in this application is as follows:

[0006] A first aspect of this application provides an engine crankcase ventilation system, the system including an intake pipe, a sealed chamber, a first gas passage, and a second gas passage.

[0007] The intake manifold is connected to the combustion chamber of the engine;

[0008] The sealed chamber is disposed on the valve cover of the engine and communicates with the intake pipe. The sealed chamber is also disconnectably communicated with the crankcase of the engine.

[0009] Both the first gas passage and the second gas passage are disposed on the cylinder of the engine, wherein the first gas passage is used to disconnectably connect the combustion chamber and the crankcase, and the second gas passage is used to disconnectably connect the sealed chamber and the crankcase.

[0010] Optionally, a first one-way valve is provided in the first gas passage. The first one-way valve is configured to allow gas to flow from the crankcase to the combustion chamber and to prevent gas from flowing from the combustion chamber to the crankcase.

[0011] Optionally, the first gas passage is disposed on the cylinder head of the cylinder, one end of the first gas passage is connected to the cylinder head intake passage, and the other end of the first gas passage is connected to the oil-gas separator of the engine, and the oil-gas separator is connected to the crankcase.

[0012] The first check valve is located at one end of the first gas passage near the oil-gas separator.

[0013] Optionally, a second one-way valve is provided in the second gas passage. The second one-way valve is used to allow gas to flow from the sealed chamber to the crankcase and to prevent gas from flowing from the crankcase to the sealed chamber.

[0014] Optionally, the second gas passage includes a first sub-passage and a second sub-passage that are connected to each other. The first sub-passage is opened through the cylinder head of the cylinder and communicates with the sealed chamber; the second sub-passage is opened through the cylinder body of the cylinder and communicates with the crankcase.

[0015] The second check valve is located in the first sub-channel or in the second sub-channel.

[0016] Optionally, the second check valve is located at the end of the first sub-channel away from the second sub-channel, or at the end of the second sub-channel away from the first sub-channel.

[0017] Optionally, the system includes at least one of a first seal and a second seal.

[0018] The first seal is integrated into the valve cover gasket and is used to seal the connection between the sealing chamber and the first sub-channel;

[0019] The second seal is integrated into the cylinder head gasket and is used to seal the connection between the first sub-channel and the second sub-channel.

[0020] Optionally, the sealed chamber is connected to the crankcase via an oil-gas separator;

[0021] The system also includes a third check valve connected between the sealed chamber and the oil-gas separator, configured to allow gas to flow from the oil-gas separator to the sealed chamber and to prevent gas from flowing from the sealed chamber to the oil-gas separator.

[0022] Optionally, the third check valve is a diaphragm valve, which is configured as follows:

[0023] When the engine is under high load, it opens to connect the sealed chamber and the oil-gas separator; and,

[0024] When the engine is under low load, it is shut down to block the connection between the sealed chamber and the oil-gas separator.

[0025] A second aspect of this application is to provide a vehicle that includes the engine crankcase ventilation system described in the first aspect.

[0026] In the engine crankcase ventilation system and vehicle provided in this application embodiment, the intake pipe, sealed chamber, second gas passage, and crankcase are sequentially connected, providing a pathway for fresh air to enter the crankcase and enabling crankcase air replenishment. The crankcase is connected to the combustion chamber via both the first gas passage and the sealed chamber and intake pipe. Therefore, the air-fuel mixture in the crankcase can be transported to the combustion chamber through these two paths to participate in combustion again, reducing the adverse effects of the air-fuel mixture on the crankcase. Moreover, since the sealed chamber is located on the engine valve cover, and the first and second gas passages are located on the engine cylinders (i.e., internal piping), it avoids occupying external engine space, saves on the cost of external piping components, and provides better reliability. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of an engine crankcase ventilation system provided in an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the structure of a diaphragm valve in the closed state according to an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of a diaphragm valve in the open state according to an embodiment of this application;

[0031] Figure 4 This is a schematic diagram illustrating the working principle of the engine crankcase ventilation system under heavy load conditions.

[0032] Figure 5 This is a schematic diagram illustrating the working principle of the engine crankcase ventilation system under low load conditions.

[0033] Figure label:

[0034] 10. Intake pipe;

[0035] 20. Sealed chamber;

[0036] 30. First gas passage;

[0037] 40. Second gas channel; 41. First sub-channel; 42. Second sub-channel;

[0038] 50. Valve chamber cover; 51. Valve body; 52. Valve cover; 53. Top pillar; 54. High-load exhaust port;

[0039] 60. Crankcase;

[0040] 70. Cylinder; 71. Cylinder head; 711. Cylinder head intake port; 72. Cylinder block;

[0041] 80. First check valve;

[0042] 90. Oil-gas separation unit;

[0043] 100. Second check valve;

[0044] 110. Third check valve; 111. Diaphragm;

[0045] 120. Supercharger;

[0046] 130. Throttling valve.

[0047] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0051] This application provides an engine crankcase ventilation system, such as... Figure 1 As shown, the system includes an intake pipe 10, a sealed chamber 20, a first gas passage 30, and a second gas passage 40. The intake pipe 10 is connected to the combustion chamber of the engine (not shown in the figure). The sealed chamber 20 is disposed on the valve cover 50 of the engine and is connected to the intake pipe 10. The sealed chamber 20 is also disconnectably connected to the crankcase 60 of the engine. The first gas passage 30 and the second gas passage 40 are both disposed on the cylinder 70 of the engine. The first gas passage 30 is used to disconnectably connect the combustion chamber and the crankcase 60, and the second gas passage 40 is used to disconnectably connect the sealed chamber 20 and the crankcase 60.

[0052] In the engine crankcase ventilation system and vehicle provided in this application embodiment, the intake pipe 10, the sealed chamber 20, the second gas passage 40, and the crankcase 60 are sequentially connected, providing a passage for fresh air to enter the crankcase 60 and enabling air replenishment to the crankcase 60. The crankcase 60 is connected to the combustion chamber through the first gas passage 30 and the sealed chamber 20 and intake pipe 10, so the air-fuel mixture in the crankcase 60 can be transported to the combustion chamber through the above two paths to participate in combustion again, reducing the adverse effects of the air-fuel mixture on the crankcase 60. Moreover, since the sealed chamber 20 is located on the valve cover 50 of the engine, and the first gas passage 30 and the second gas passage 40 are located on the cylinder 70 of the engine (i.e., the pipes are built-in), the occupation of external engine space is avoided, saving the cost of external pipe parts and providing better reliability.

[0053] The following is in conjunction with the appendix Figure 1-5 The present application provides a more detailed description of the engine crankcase ventilation system provided in the embodiments.

[0054] like Figure 1 As shown, the intake manifold 10 is connected to the combustion chamber of the engine and is used to supply fresh air to the combustion chamber. The source of the fresh air in the intake manifold 10 can be outside air or processed compressed air.

[0055] Optionally, a turbocharger 120 and / or a throttle valve 130 may also be installed on the intake manifold 10 to further improve engine performance. The turbocharger compresses air, increasing its density and allowing more air to enter the combustion chamber of the cylinder 70, thereby increasing engine power. The throttle valve 130 controls the gas flow rate in the intake manifold 10, thus controlling the engine's output power and ensuring optimal air supply under various operating conditions. The combined action of the turbocharger 120 and the throttle valve 130 effectively improves engine performance and efficiency.

[0056] See also Figure 1 A sealed chamber 20 is formed on the valve cover 50 of the engine. Optionally, the valve cover 50 has a valve body 51 and a valve cover 52 covering the valve body 51, with at least one gap between the valve body 51 and the valve cover 52, thereby forming the sealed chamber 20.

[0057] The sealed chamber 20 is connected to the intake pipe 10, meaning that fresh air in the intake pipe 10 can flow into the sealed chamber 20, or, after the oil-gas mixture flows into the sealed chamber 20, the oil-gas mixture can enter the intake pipe 10 and mix with fresh air.

[0058] The sealed chamber 20 is also in disconnectable communication with the engine crankcase 60. It should be noted that, in this embodiment, "disconnectable communication" means that under certain conditions, the sealed chamber 20 and the crankcase 60 are interconnected, allowing gas exchange; however, if these conditions are not met, the sealed chamber 20 and the crankcase 60 are not interconnected, and gas cannot flow from one chamber to the other. Optionally, the above conditions may relate to at least one of the following: gas flow direction, gas pressure, gas flow rate, gas temperature, and on / off control requirements (control commands).

[0059] In one example, when the gas pressure in the sealed chamber 20 is greater than the gas pressure in the crankcase 60, the sealed chamber 20 is connected to the crankcase 60, and fresh air in the sealed chamber 20 can enter the crankcase 60; when the gas pressure in the sealed chamber 20 is less than or equal to the gas pressure in the crankcase 60, the sealed chamber 20 is not connected to the crankcase 60.

[0060] In another example, when there is a need for air replenishment, a conduction control command can be issued to connect the sealed chamber 20 with the crankcase 60, thereby facilitating the entry of fresh air into the crankcase 60; when there is no need for air replenishment, a cut-off control command can be issued to disconnect the sealed chamber 20 from the crankcase 60, thereby preventing fresh air from entering the crankcase 60 and preventing the oil-air mixture in the crankcase 60 from flowing out to the sealed chamber 20.

[0061] A first gas passage 30 and a second gas passage 40 are formed on the cylinder 70 of the engine. The first gas passage 30 is located between the combustion chamber and the crankcase 60, allowing the crankcase 60 and the combustion chamber to be connected in a cut-off manner. When the crankcase 60, the first gas passage 30, and the combustion chamber are connected in sequence, the air-fuel mixture in the crankcase 60 can enter the combustion chamber through the first gas passage 30 and participate in combustion again. The second gas passage 40 is located between the sealed chamber 20 and the crankcase 60, allowing the sealed chamber 20 and the crankcase 60 to be connected in a cut-off manner. When the sealed chamber 20, the second gas passage 40, and the crankcase 60 are connected in sequence, fresh air in the sealed chamber 20 can enter the crankcase 60 through the second gas passage 40, thereby achieving air replenishment to the crankcase 60.

[0062] It should be noted that the condition of "the crankcase and combustion chamber can be disconnected" may be the same as or different from the condition of "the sealed chamber and crankcase can be disconnected".

[0063] In some embodiments of this application, the first gas passage 30 can be disconnected from the combustion chamber and the crankcase 60, which can be achieved by providing a first check valve 80 within the first gas passage 30. The first check valve 80 is configured to allow the air-fuel mixture in the crankcase 60 to flow into the combustion chamber, and to prevent the air-fuel mixture in the combustion chamber from flowing into the crankcase 60.

[0064] Optionally, the first one-way valve 80 may be a PCV (Positive Crankcase Ventilation) valve. The PCV valve can controllably guide the air-fuel mixture in the crankcase 60 into the combustion chamber, thereby preventing blow-by into the atmosphere and preventing the engine oil in the crankcase 60 from deteriorating.

[0065] For example, when the vehicle's engine is under high load, the PVC valve is closed, preventing the air-fuel mixture in the crankcase 60 from directly entering the combustion chamber. When the engine is under low load, the PVC valve is open, allowing the air-fuel mixture in the crankcase 60 to directly enter the combustion chamber. High load generally refers to the throttle being close to or fully open, requiring the engine to output maximum power to overcome significant external resistance or accelerate. Low load generally refers to the throttle opening being less than 25%, requiring a rich air-fuel mixture to enter the cylinder.

[0066] In some examples, the first gas passage 30 may be a ventilation pipe with a PCV valve installed between the intake line 10 and the crankcase 60.

[0067] In other examples, the first gas passage 30 may be a through hole provided on the cylinder head 71 of the cylinder 70, one end of which is connected to the cylinder head intake passage 711 and the other end is connected to the crankcase 60, and a PVC valve is installed in the through hole.

[0068] Optionally, an oil-gas separator 90 is further provided between the crankcase 60 and the first gas passage 30. This oil-gas separator 90 separates engine oil from the oil-gas mixture discharged from the crankcase 60, thereby ensuring that engine oil is not arbitrarily released to the outside of the engine. For example, the oil-gas separator 90 can be located at a vent position in the crankcase 60 for communication with the first gas passage 30, with its two ends connected to the other ends of the crankcase 60 and the first gas passage 30, respectively.

[0069] Optionally, the first check valve 80 may be located at one end of the first gas passage 30 near the oil-gas separator 90 for ease of installation and maintenance.

[0070] In some embodiments of this application, the second gas passage 40 can be disconnected from the sealed chamber 20 and the crankcase 60, which can be achieved by providing a second one-way valve 100 within the second gas passage 40. The second one-way valve 100 is configured to allow fresh air in the sealed chamber 20 to flow to the crankcase 60, and to prevent the flow of the oil-gas mixture in the crankcase 60 to the sealed chamber 20.

[0071] like Figure 1 As shown, the second gas passage 40 may include a first sub-passage 41 disposed on the cylinder head 71 of the cylinder 70, and a second sub-passage 42 disposed on the cylinder body 72 of the cylinder 70, wherein the first sub-passage 41 and the second sub-passage 42 respectively pass through the cylinder head 71 and the cylinder body 72, and after the cylinder head 71 and the cylinder body 72 are assembled, the first sub-passage 41 and the second sub-passage 42 are connected accordingly.

[0072] The second gas passage 40 is the gas injection passage used to inject gas into the crankcase 60. Compared with the external gas injection line in related technologies, this embodiment uses an internal gas injection passage, which is located on the cylinder head 71 and cylinder block 72 of the cylinder 70. On the one hand, this reduces the space required for engine layout and reduces the overall size of the engine; on the other hand, compared with the external pipeline, it reduces the number of components such as the gas injection line, quick connectors, fixing brackets and bolts, and there is no need to install connectors on the intake hose, thus reducing manufacturing and assembly costs; furthermore, the reliability of the internal pipeline is better than that of the external pipeline, which is conducive to meeting the regulatory requirements related to the ventilation and emission of pollutants from the crankcase 60 to a higher standard.

[0073] In the above embodiments, the second check valve 100 can be disposed within the first sub-channel 41 or within the second sub-channel 42. Optionally, the second check valve 100 is located at the end of the first sub-channel 41 away from the second sub-channel 42, or at the end of the second sub-channel 42 away from the first sub-channel 41, to facilitate assembly and maintenance.

[0074] In this embodiment, the valve cover 50 is generally mounted on the cylinder head 71 of the cylinder 70, thereby sealing the cavity 20 and correspondingly communicating with the first sub-channel 41.

[0075] Optionally, a first seal (not shown in the figure) is used to seal the connection between the sealing chamber 20 and the first sub-channel 41, and / or a second seal (not shown in the figure) is used to seal the connection between the first sub-channel 41 and the second sub-channel 42 to prevent the flowing gas from escaping from the connection. The first seal can be integrated into the valve cover 50 gasket, which is located between the valve cover 50 and the cylinder head 71 of the cylinder 70, for sealing the connection between the two. The second seal can be integrated into the cylinder 70 gasket, which is located between the cylinder head 71 and the cylinder block 72 of the cylinder 70, for sealing the connection between the two.

[0076] Optionally, the first seal and the second seal are selected from any one of rubber gaskets, metal-asbestos gaskets, metal-composite gaskets, and all-metal gaskets.

[0077] In some embodiments of this application, the sealed chamber 20 is disconnectably connected to the crankcase 60, which can be achieved by providing a third check valve 110 within the sealed chamber 20. The third check valve 110 is configured to allow the oil-air mixture in the crankcase 60 to flow into the sealed chamber 20, and to prevent fresh air in the sealed chamber 20 from flowing into the crankcase 60.

[0078] Optionally, the third check valve 110 may be a diaphragm valve.

[0079] Figure 2 This illustration shows a schematic diagram of a diaphragm valve in the closed state according to an embodiment of this application. Figure 3 A schematic diagram of the diaphragm valve in the open state is shown. Figure 2 and Figure 3As shown, a high-load exhaust port 54 is provided through the valve body 51 of the valve chamber cover 50, which connects the crankcase 60 and the sealing chamber 20. A top post 53 protrudes from the valve body 51 towards the valve cover 52. The diaphragm 111 of the diaphragm valve has a through hole, allowing it to be fitted onto the top post 53. Due to the gap between the valve cover 52 and the valve body 51, the diaphragm 111 can move up and down along the protruding direction of the top post 53. The solid portion of the diaphragm 111 completely covers all the high-load exhaust ports 54, enabling the diaphragm valve to open and close the high-load exhaust ports 54 according to the gas flow conditions.

[0080] In some embodiments of this application, the diaphragm valve is configured to: open when the engine is under high load to connect the sealed chamber 20 and the crankcase 60; and close when the engine is under low load to block the connection between the sealed chamber 20 and the crankcase 60.

[0081] When the engine is under heavy load, the gas pressure in the crankcase 60 is relatively high. The air-fuel mixture in the crankcase 60 will push up the diaphragm 111 in the diaphragm valve, thereby opening the diaphragm valve and allowing the air-fuel mixture to flow into the sealed chamber 20. When the engine is under light load, the gas pressure in the crankcase 60 is relatively low. The air-fuel mixture pressure in the crankcase 60 is insufficient to push up the diaphragm 111 in the diaphragm valve, so the diaphragm valve remains closed and the air-fuel mixture cannot flow into the sealed chamber 20.

[0082] Optionally, an oil-gas separator 90 is further provided between the crankcase 60 and the sealed chamber 20. Exemplarily, the oil-gas separator 90 may be located at a vent position in the crankcase 60 for communication with the sealed chamber 20, with its two ends connected to the crankcase 60 and a third check valve 110 located in the sealed chamber 20, respectively. Therefore, the third check valve 110 can restrict the gas flow direction between the oil-gas separator 90 and the sealed chamber 20, i.e., allowing gas to flow from the oil-gas separator 90 to the sealed chamber 20, and preventing gas from flowing from the sealed chamber 20 to the oil-gas separator 90.

[0083] Optionally, the oil-gas separator 90 and the oil-gas separator 90 disposed between the crankcase 60 and the first gas passage 30 may be the same oil-gas separator or two independent oil-gas separators.

[0084] Optionally, the oil-gas separation section 90 in the embodiments of this application can be an oil-gas separator or a labyrinthine oil-gas separation channel provided on the corresponding component.

[0085] The following is combined Figure 4-5 The working principle of the engine crankcase ventilation system provided in the embodiments of this application is described below:

[0086] like Figure 4 As shown, when the engine is operating under heavy load, the first one-way valve 80 is closed. At this time, the gas pressure in the intake manifold 10 is lower than the gas pressure in the crankcase 60. Under the combined action of the positive pressure in the crankcase 60 and the negative pressure in the intake manifold 10, the diaphragm 111 in the third one-way valve 110 moves upward (as shown). Figure 3 As shown in the diagram, the third one-way valve 110 is opened, and the oil-air mixture in the crankcase 60 passes through the oil-air separator 90 and enters the sealed chamber 20 through the high-load outlet 54, then enters the intake manifold 10, and then enters the cylinder head intake manifold 711 through the turbocharger 120 and throttle valve 130, subsequently entering the combustion chamber to participate in combustion. During this process, because the gas pressure in the crankcase 60 is greater than the gas pressure in the sealed chamber 20, the second one-way valve 100 remains closed.

[0087] like Figure 5 As shown, when the engine is operating under low load, the first one-way valve 80 opens, the gas pressure in the crankcase 60 is negative, and the diaphragm 111 in the third one-way valve 110 moves under the suction of the negative pressure (as shown). Figure 2 As shown in the diagram, the third one-way valve 110 is closed, and the high-load exhaust port 54 is blocked. Simultaneously, fresh air in the intake manifold 10 flows into the crankcase 60 through the sealed chamber 20 and the second gas passage 40 under the suction of negative pressure, thus replenishing the crankcase 60 with fresh air. After mixing with the air-fuel mixture in the crankcase 60, the fresh air passes sequentially through the oil-gas separator 90 and the first one-way valve 80 into the cylinder head intake manifold 711, and then enters the combustion chamber to participate in combustion.

[0088] This application also provides a vehicle whose engine has the aforementioned crankcase ventilation system.

[0089] Alternatively, the vehicle can be a gasoline-powered vehicle, a hybrid vehicle, or any other type of vehicle, as long as it has an engine.

[0090] The vehicle provided in this application embodiment adopts the above-mentioned crankcase ventilation system, in which the intake pipe 10, the sealed chamber 20, the second gas passage 40 and the crankcase 60 are connected in sequence, providing a passage for fresh air to enter the crankcase 60, and enabling the crankcase 60 to be replenished with air; the crankcase 60 is connected to the combustion chamber on the one hand through the first gas passage 30, and on the other hand through the sealed chamber 20 and the intake pipe 10, so the oil-air mixture in the crankcase 60 can be transported to the combustion chamber through the above two paths to participate in combustion again, reducing the adverse effects of the oil-air mixture on the crankcase 60.

[0091] Furthermore, since the sealed chamber 20 is located on the valve cover 50 of the engine, and the first gas passage 30 and the second gas passage 40 are located on the cylinder 70 of the engine (i.e., the pipelines are built-in), the occupation of external space for the engine is avoided, the overall size of the engine is reduced, the space requirement is reduced, the cost of external pipeline parts is saved, and the reliability is better.

[0092] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0093] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An engine crankcase ventilation system, characterized in that, The system includes an intake pipe (10), a sealed chamber (20), a first gas passage (30), and a second gas passage (40). The intake pipe (10) is connected to the combustion chamber of the engine; The sealed chamber (20) is disposed on the valve cover (50) of the engine and is connected to the intake pipe (10). The sealed chamber (20) is also disconnectably connected to the crankcase (60) of the engine. The first gas passage (30) and the second gas passage (40) are both disposed on the cylinder (70) of the engine, wherein the first gas passage (30) is used to disconnectably connect the combustion chamber and the crankcase (60), and the second gas passage (40) is used to disconnectably connect the sealed chamber (20) and the crankcase (60); A second one-way valve (100) is provided in the second gas passage (40). The second one-way valve (100) is used to allow gas to flow from the sealed chamber (20) to the crankcase (60) and to prevent gas from flowing from the crankcase (60) to the sealed chamber (20). The second gas passage (40) includes a first sub-passage (41) and a second sub-passage (42) that are connected to each other. The first sub-passage (41) passes through the cylinder head (71) of the cylinder (70) and communicates with the sealed chamber (20). The second sub-passage (42) passes through the cylinder body (72) of the cylinder (70) and communicates with the crankcase (60). The second check valve (100) is located in the first sub-channel (41) or in the second sub-channel (42).

2. The system according to claim 1, characterized in that, A first check valve (80) is provided in the first gas passage (30). The first check valve (80) is configured to allow gas to flow from the crankcase (60) to the combustion chamber and to prevent gas from flowing from the combustion chamber to the crankcase (60).

3. The system according to claim 2, characterized in that, The first gas passage (30) is disposed on the cylinder head (71) of the cylinder (70). One end of the first gas passage (30) is connected to the cylinder head intake passage (711), and the other end of the first gas passage (30) is connected to the oil-gas separator (90) of the engine. The oil-gas separator (90) is connected to the crankcase (60). The first check valve (80) is located at one end of the first gas passage (30) near the oil-gas separator (90).

4. The system according to claim 1, characterized in that, The second check valve (100) is located at one end of the first sub-channel (41) away from the second sub-channel (42), or at one end of the second sub-channel (42) away from the first sub-channel (41).

5. The system according to claim 1, characterized in that, The system includes at least one of a first seal and a second seal. The first seal is integrated on the valve cover gasket and is used to seal the connection between the sealing chamber (20) and the first sub-channel (41); The second seal is integrated into the cylinder head gasket and is used to seal the connection between the first sub-channel (41) and the second sub-channel (42).

6. The system according to claim 1, characterized in that, The sealed chamber (20) is connected to the crankcase (60) through the oil-gas separator (90); The system also includes a third check valve (110) configured to allow gas to flow from the oil-gas separator (90) to the sealed chamber (20) and to prevent gas from flowing from the sealed chamber (20) to the oil-gas separator (90).

7. The system according to claim 6, characterized in that, The third check valve (110) is a diaphragm valve, which is configured as follows: When the engine is under heavy load, it opens to connect the sealed chamber (20) and the oil-gas separator (90); and, When the engine is under low load, it is shut off to block the connection between the sealed chamber (20) and the oil-gas separator (90).

8. A vehicle, characterized in that, The vehicle includes the engine crankcase (60) ventilation system as described in any one of claims 1-7.

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