Crankcase ventilation systems and vehicles

Abstract

The present application discloses a crankcase ventilation system and a vehicle, belonging to the field of vehicle technology. The crankcase ventilation system includes a crankcase, a first ventilation line, a second ventilation line and an air supply line; the two ends of the first ventilation line are respectively connected to the crankcase and the intake manifold of the engine, and a first valve is arranged on the first ventilation line; the two ends of the second ventilation line are respectively connected to the crankcase and the intake line of the supercharger, and a second valve is arranged on the second ventilation line; the two ends of the air supply line are respectively connected to the crankcase, the intake line between the throttle and the supercharger, and a third valve is arranged on the air supply line. The present application reduces the influence of exhaust gas on the engine oil in the crankcase and increases the service life of the engine oil.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a crankcase ventilation system and a vehicle. Background Art

[0002] During the operation of the engine, a large amount of exhaust gas is generated in the crankcase. In order to prevent the exhaust gas in the crankcase from being discharged into the atmosphere to pollute the environment, and to prevent the exhaust gas in the crankcase from oxidizing or acidifying the engine oil in the crankcase, thereby reducing the service life of the engine oil, people have proposed a crankcase ventilation system, that is, to circulate the exhaust gas in the crankcase into the engine intake manifold, and then enter the engine cylinder head to participate in re-combustion. The current crankcase ventilation system includes a crankcase, a first branch and a second branch. The crankcase ventilation system and the engine intake pipe are interconnected to realize the exhaust gas circulation of the crankcase.

[0003] The engine's air intake line includes a supercharger, a throttle valve, and an intake manifold. The throttle valve's air intake is connected to the engine's supercharger's air outlet, the supercharger's air intake is connected to the outside air, and the throttle valve's air outlet is connected to the intake manifold. When the engine is in a low-load state, the supercharger does not work, and when the engine is in a high-load state, the supercharger works.

[0004] The two ends of the first branch are connected to the crankcase and the intake manifold respectively. When the engine is in a low-load state, the air pressure in the crankcase is a large positive pressure, and the air pressure in the part of the intake manifold connected to the first branch is a negative pressure. Therefore, under the action of the pressure difference, the exhaust gas in the crankcase can be circulated to the intake manifold through the first branch for subsequent re-combustion, but a part of the exhaust gas will still remain in the crankcase.

[0005] The two ends of the second branch are connected to the crankcase and the intake pipe between the throttle and the supercharger. When the engine is in a high load state, the supercharger starts to work, so that the air pressure at the intake pipe between the throttle and the supercharger (the part where the throttle and the supercharger are connected) is a relatively high positive pressure. At this time, in order to prevent the gas in the intake manifold from flowing into the crankcase, the first branch is closed. Since the air pressure in the crankcase is a relatively low positive pressure or even a negative pressure at this time, very little exhaust gas in the crankcase enters the throttle, resulting in the exhaust gas in the crankcase remaining in the crankcase.

[0006] The exhaust gas in the crankcase will oxidize or acidify the engine oil, reducing the service life of the engine oil. Summary of the invention

[0007] The embodiments of the present application provide a crankcase ventilation system and a vehicle, which can solve the technical problems existing in the related art. The technical solutions are as follows:

[0008] On the one hand, an embodiment of the present application provides a crankcase ventilation system, the crankcase ventilation system comprising a crankcase, a first ventilation line, a second ventilation line and an air supply line;

[0009] The two ends of the first ventilation line are respectively connected to the crankcase and the intake manifold of the engine. The first ventilation line is provided with a first valve, and the first valve is used to open the first ventilation line when the engine is in a low load state, and close the first ventilation line when the engine is in a high load state;

[0010] The two ends of the second ventilation pipeline are respectively connected to the crankcase and the intake pipeline of the supercharger, and a second valve is arranged on the second ventilation pipeline, and the second valve is used to limit the flow of gas flowing in the second ventilation pipeline when the engine is in a low load state, and to completely open the second ventilation pipeline when the engine is in a high load state;

[0011] The two ends of the air supply pipeline are respectively connected to the crankcase, the throttle and the intake pipeline between the supercharger, and a third valve is arranged on the air supply pipeline. The third valve is used to close the air supply pipeline when the engine is in a low load state and to open the air supply pipeline when the engine is in a high load state.

[0012] In one possible implementation, the crankcase is respectively connected to the first end of the first built-in channel of the cylinder head of the engine and the first end of the second built-in channel of the cylinder head, the second end of the first built-in channel of the cylinder head is connected to the first end of the third built-in channel of the valve chamber cover of the engine, the second end of the second built-in channel of the cylinder head is connected to the first end of the fourth built-in channel of the valve chamber cover, the second end of the third built-in channel of the valve chamber cover is connected to the first ventilation duct, and the second end of the fourth built-in channel of the valve chamber cover is connected to the second ventilation duct.

[0013] In one possible implementation, the crankcase ventilation system also includes a first oil-gas separation module, both ends of which are respectively connected to the crankcase and the first ventilation duct, for preventing the oil carried in the exhaust gas in the crankcase from entering the first ventilation duct.

[0014] In a possible implementation, the first valve includes a first plunger valve, and the first plunger valve is disposed on the first ventilation pipeline.

[0015] In a possible implementation, the second valve includes a first one-way valve and a flow-limiting hole;

[0016] The first one-way valve is arranged on the second ventilation pipeline, the flow direction of the first one-way valve is from the crankcase to the intake pipeline of the supercharger, and the position of the flow restriction hole corresponds to the position of the first one-way valve;

[0017] When the engine is in a low-load state, the first one-way valve is used to partially cut off the air flowing from the intake line of the supercharger into the second ventilation line, and the flow restriction hole is used to conduct the remaining air not cut off by the first one-way valve;

[0018] When the engine is in a high load state, the first one-way valve and the flow restriction hole are used to completely open the second ventilation line so that the exhaust gas in the crankcase flows toward the intake line of the supercharger.

[0019] In a possible implementation manner, a cross-sectional area of ​​the flow limiting hole is smaller than a preset value.

[0020] In one possible implementation, the crankcase ventilation system also includes a second oil-gas separation module, the two ends of which are respectively connected to the crankcase and the second ventilation duct, for preventing the oil carried in the exhaust gas in the crankcase from entering the second ventilation duct.

[0021] In a possible implementation, the third valve includes a second plunger valve, and the second plunger valve is disposed on the air supply pipeline.

[0022] In a possible implementation, the third valve further includes a second one-way valve;

[0023] The second one-way valve is located between the crankcase and the second plunger valve and is arranged on the air supply pipeline. The flow direction of the second one-way valve is from the air intake pipeline between the throttle valve and the supercharger to the crankcase.

[0024] On the other hand, an embodiment of the present application provides a vehicle, comprising a crankcase ventilation system as described in any one of the above items.

[0025] The technical solution provided by the embodiments of the present application includes at least the following beneficial effects:

[0026] An embodiment of the present application provides a crankcase ventilation system, which includes a crankcase, a first ventilation line, a second ventilation line, and an air supply line.

[0027] When the engine is in a low-load state, the air pressure in the crankcase is a relatively high positive pressure, and the air pressure at the position of the intake manifold connected to the first ventilation line is a negative pressure. At this time, the first valve is opened, and the first ventilation line is connected. Under the action of the pressure difference between the crankcase and the intake manifold, the exhaust gas in the crankcase can flow into the intake manifold through the first ventilation line. At the same time, as the exhaust gas in the crankcase is discharged, the air pressure in the crankcase decreases. At this time, a small amount of outside air can enter the crankcase through the second ventilation line to dilute the exhaust gas in the crankcase and squeeze part of the exhaust gas in the crankcase into the intake manifold, thereby reducing the impact of the exhaust gas on the engine oil in the crankcase and increasing the service life of the engine oil.

[0028] When the engine is in a high load state, the air pressure in the crankcase is a relatively low positive pressure or even a negative pressure. Since the supercharger starts to work, the air pressure at the intake pipe of the supercharger is relatively low, and the air pressure at the intake pipe between the throttle and the supercharger is a relatively high positive pressure. At this time, the second valve is opened, the second ventilation pipe is connected, the third valve is opened, the air supply pipe is connected, and the air at the air inlet of the throttle can enter the crankcase through the air supply pipe to dilute the exhaust gas in the crankcase, and squeeze a part of the exhaust gas into the second exhaust pipe, enter the intake pipe of the supercharger through the second exhaust pipe, and then enter the intake manifold through the supercharger and the throttle valve, thereby reducing the influence of the exhaust gas on the engine oil in the crankcase and increasing the service life of the engine oil.

[0029] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 is a structural schematic diagram of a crankcase ventilation system shown in an embodiment of the present application;

[0032] Figure 2 is a schematic diagram of the exhaust direction of a crankcase ventilation system when the engine is in a low-load state, shown in an embodiment of the present application;

[0033] Figure 3 is a schematic diagram of the exhaust direction of a crankcase ventilation system when an engine is in a high-load state, shown in an embodiment of the present application;

[0034] Figure 4It is a structural schematic diagram of a second valve shown in an embodiment of the present application.

[0035] Legend

[0036] 1. Crankcase; 2. First ventilation pipeline; 3. Second ventilation pipeline; 4. Air supply pipeline; 5. First oil-gas separation module; 6. Second oil-gas separation module;

[0037] 21, first valve; 31, second valve; 41, third valve;

[0038] 311, first one-way valve; 312, flow limiting hole; 411, second plunger valve; 412, second one-way valve;

[0039] 10. Intake manifold; 11. Supercharger; 12. Cylinder head; 13. Valve cover; 14. Throttle valve;

[0040] 121, first built-in channel; 122, second built-in channel; 131, third built-in channel; 132, fourth built-in channel. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0042] The present application embodiment provides a crankcase ventilation system, such as Figure 1 As shown, the crankcase ventilation system includes a crankcase 1 , a first ventilation line 2 , a second ventilation line 3 and an air supply line 4 .

[0043] Below, each device is introduced separately:

[0044] Crankcase 1

[0045] When the engine is in a low-load state, the air pressure in the crankcase 1 is a relatively high positive pressure. When the engine is in a high-load state, the air pressure in the crankcase 1 is a relatively low positive pressure or even a negative pressure.

[0046] First ventilation line 2

[0047] The two ends of the first ventilation line 2 are respectively connected to the crankcase 1 and the intake manifold 10 of the engine, and a first valve 21 is provided on the first ventilation line 2. The first valve 21 is used to conduct the first ventilation line 2 when the engine is in a low load state, and to close the first ventilation line 2 when the engine is in a high load state.

[0048] See also Figure 2When the engine is in a low-load state, the first valve 21 opens, so that the first ventilation line 2 is connected, the crankcase 1 is at a relatively high positive pressure, and the intake manifold 10 is at a negative pressure. At this time, under the action of the pressure difference between the crankcase 1 and the intake manifold 10, the exhaust gas in the crankcase 1 can be discharged into the intake manifold 10 through the first ventilation line 2 for subsequent reburning.

[0049] Moreover, at this time, the second valve 31 on the second ventilation line 3 is not closed, and the second valve 31 can allow a smaller amount of gas to flow. Therefore, as the exhaust gas in the crankcase 1 decreases, the air pressure in the crankcase 1 decreases, and a small amount of outside air can flow into the crankcase 1 through the second ventilation line 3 to dilute the exhaust gas remaining in the crankcase 1, thereby reducing the oxidation and acidification of the engine oil by the exhaust gas and increasing the service life of the engine oil.

[0050] When the engine is in a high load state, the first valve 21 is closed, so that the first ventilation line 2 is not conductive.

[0051] Second ventilation line 3

[0052] The two ends of the second ventilation line 3 are respectively connected to the crankcase 1 and the intake line of the supercharger 11. A second valve 31 is provided on the second ventilation line 3. The second valve 31 is used to limit the flow of gas flowing in the second ventilation line 3 when the engine is in a low load state, and to fully open the second ventilation line 3 when the engine is in a high load state.

[0053] When the engine is in a low-load state, the second valve 31 limits the flow of gas in the second ventilation line 3, that is, the second ventilation line 3 is not completely closed, and a small amount of gas is allowed to flow. At this time, outside air can enter the crankcase 1 through the second ventilation line 3, which has been introduced in the above content related to the first ventilation line 2 and will not be repeated here.

[0054] When the engine is in a high load state, the second valve 31 is opened, so that the second ventilation pipeline 3 is largely open. This situation will be described in conjunction with the flow of the air supply pipeline 4 in the following content.

[0055] Air supply line 4

[0056] The two ends of the air supply pipeline are respectively connected to the crankcase 1, the throttle 14 and the intake pipeline between the supercharger 11. A third valve 41 is provided on the air supply pipeline 4. The third valve 41 is used to close the air supply pipeline 4 when the engine is in a low load state, and to conduct the air supply pipeline 4 when the engine is in a high load state.

[0057] When the engine is in a low-load state, the third valve 41 is closed and the air supply pipeline 4 is not conducting.

[0058] See also Figure 3 When the engine is in a high load state, the third valve 41 is opened and the air supply pipe 4 is connected. At this time, the air pressure in the crankcase 1 is a relatively low positive pressure or even a negative pressure, and since the supercharger 11 starts to work, the air pressure at the air intake pipe of the supercharger 11 is relatively low, and the air pressure at the air intake pipe between the throttle 14 and the supercharger 11 is relatively high positive pressure. At this time, the air at the air intake pipe between the throttle 14 and the supercharger 11 can enter the crankcase 1 through the air supply pipe 4, dilute the exhaust gas in the crankcase 1, and squeeze a part of the exhaust gas into the second ventilation pipe 3, enter the air intake pipe of the supercharger 11 through the second ventilation pipe 3, and then enter the intake manifold 10 through the supercharger 11 and the throttle 14, thereby reducing the influence of the exhaust gas on the engine oil in the crankcase 1 and increasing the service life of the engine oil.

[0059] In summary, adopt this application, see Figure 2 When the engine is in a low-load state, the air pressure in the crankcase 1 is a relatively high positive pressure, and the air pressure at the position of the intake manifold 10 connected to the first ventilation pipe 2 is a negative pressure. At this time, the first valve 21 is opened, and the first ventilation pipe 2 is connected. Under the action of the pressure difference between the crankcase 1 and the intake manifold 10, the exhaust gas in the crankcase 1 can flow into the intake manifold 10 through the first ventilation pipe 2. At the same time, as the exhaust gas in the crankcase 1 is discharged, the air pressure in the crankcase 1 decreases. At this time, a small amount of external air can enter the crankcase 1 through the second ventilation pipe 3 to dilute the exhaust gas in the crankcase 1 and squeeze a part of the exhaust gas in the crankcase 1 into the intake manifold 10, thereby reducing the influence of the exhaust gas on the engine oil in the crankcase 1 and improving the service life of the engine oil.

[0060] When the engine is under high load, see Figure 3 , the air pressure in the crankcase 1 is a relatively low positive pressure or even a negative pressure, and because the supercharger 11 starts to work, the air pressure at the intake pipe of the supercharger 11 is relatively low, and the air pressure at the intake pipe between the throttle 14 and the supercharger 11 is a relatively high positive pressure. At this time, the second valve 31 is opened, the second ventilation pipe 3 is connected, the third valve 41 is opened, and the air in the intake pipe between the throttle 14 and the supercharger 11 can enter the crankcase 1 through the air supply pipe 4, dilute the exhaust gas in the crankcase 1, and squeeze a part of the exhaust gas into the second ventilation pipe 3, enter the intake pipe of the supercharger 11 through the second ventilation pipe 3, and then enter the intake manifold 10 through the supercharger 11 and the throttle 14, thereby reducing the influence of the exhaust gas on the engine oil in the crankcase 1 and improving the service life of the engine oil.

[0061] Next, the communication structure between the first ventilation pipeline 2, the second ventilation pipeline 3 and the crankcase 1 is introduced:

[0062] The engine includes a cylinder head 12 and a valve cover 13 . The cylinder head 12 has a first built-in passage 121 and a second built-in passage 122 . The valve cover 13 has a third built-in passage 131 and a fourth built-in passage 132 .

[0063] The connection structure between the first ventilation duct 2 and the crankcase 1 is: the crankcase 1 is connected to the first end of the first built-in channel 121 of the cylinder head 12 of the engine, the second end of the first built-in channel 121 of the cylinder head 12 is connected to the first end of the third built-in channel 131 of the valve chamber cover 13 of the engine, and the second end of the third built-in channel 131 is connected to the first ventilation duct 2, thereby realizing the connection between the crankcase 1 and the first ventilation duct 2.

[0064] The connecting structure between the second ventilation duct 3 and the crankcase 1 is: the crankcase 1 is connected to the first end of the second built-in channel 122 of the cylinder head 12 of the engine, the second end of the second built-in channel 122 of the cylinder head 12 is connected to the first end of the fourth built-in channel 132 of the valve chamber cover 13 of the engine, and the second end of the fourth built-in channel 132 of the valve chamber cover 13 is connected to the second ventilation duct 3, thereby realizing the connection between the crankcase 1 and the second ventilation duct 3.

[0065] Through the above-mentioned built-in channel of the engine, the connection between the crankcase 1 and the first ventilation pipeline 2 and the connection between the crankcase 1 and the second ventilation pipeline 3 are realized, which is simpler and more convenient.

[0066] Next, the first valve 21, the second valve 31 and the third valve 41 are introduced:

[0067] The first valve 21 is used to open the first ventilation line 2 when the engine is in a low load state, and close the first ventilation line 2 when the engine is in a high load state. The second valve 31 is used to limit the flow of gas flowing in the second ventilation line 3 when the engine is in a low load state, and fully open the second ventilation line 3 when the engine is in a high load state. The third valve 41 is used to close the air supply line 4 when the engine is in a low load state, and open the air supply line 4 when the engine is in a high load state.

[0068] In a possible implementation, the first valve 21 , the second valve 31 , and the third valve 41 may be electrically controlled valves, and the first valve 21 , the second valve 31 , and the third valve 41 are all electrically connected to a controller of the vehicle.

[0069] When the controller detects that the engine is in a low-load state, the first valve 21 may be controlled to open, the second valve 31 is still in a flow-limiting state, and the third valve 41 is controlled to close.

[0070] When the controller detects that the engine is in a high load state, the first valve 21 may be controlled to be closed, and the second valve 31 and the third valve 41 may be controlled to be opened.

[0071] In a possible implementation, the first valve 21, the second valve 31 and the third valve 41 are not electrically controlled valves, and their structures may be as follows:

[0072] The first valve 21 includes a first plunger valve, which is disposed on the first ventilation pipeline 2. In the embodiment of the present application, the first valve 21 may be a first plunger valve. The plunger valve is opened or closed according to the pressure difference between the inlet and the outlet.

[0073] In an embodiment of the present application, when the engine is in a low-load state, the air pressure in the crankcase 1 is higher and the air pressure in the intake manifold 10 is lower. At this time, the pressure difference between the crankcase 1 and the intake manifold 10 can cause the first plunger valve to be turned on, and then the first ventilation line 2 to be turned on.

[0074] When the engine is in a high-load state, the air pressure in the crankcase 1 is low, and the air pressure in the intake manifold 10 is high. At this time, the pressure difference between the crankcase 1 and the intake manifold 10 can cause the first plunger valve to close in the reverse direction.

[0075] The second valve 31 may include a first check valve 311 and a flow restriction hole 312 .

[0076] The first one-way valve 311 is arranged on the second ventilation pipeline 3. The flow direction of the first one-way valve 311 is from the crankcase 1 to the intake pipeline of the supercharger 11. The position of the flow restriction hole 312 corresponds to the position of the first one-way valve 311, that is: Figure 4 As shown, the first one-way valve 311 does not act completely on the flow cross section of the second ventilation pipeline 3 , but only acts on a part of the flow cross section thereof, and the other part of the flow cross section is the flow limiting hole 312 .

[0077] See also Figure 2 When the engine is in a low-load state, the first one-way valve 311 is used to partially cut off the air flowing from the intake pipe of the supercharger 11 to the second ventilation pipe 3, and the flow restriction hole 312 is used to conduct the remaining air that is not cut off by the first one-way valve 311. That is, when the engine is in a low-load state, the air pressure in the crankcase 1 is relatively high, and the air pressure at the intake pipe of the supercharger 11 is relatively low. As the exhaust gas in the crankcase 1 is discharged into the intake manifold 10, the air pressure in the crankcase 1 gradually decreases. At this time, the outside air can flow into the crankcase 1 through the flow restriction hole 312 in the second valve 31 to dilute the exhaust gas in the crankcase 1.

[0078] The cross-sectional area of ​​the flow limiting hole 312 is smaller than the preset value to limit the gas flow of the flow limiting hole 312. The preset value may be 1 / 12 of the cross-sectional area of ​​the internal passage of the second ventilation pipeline 3, etc. It may be set according to the requirements, and the embodiment of the present application does not limit this.

[0079] See also Figure 3 When the engine is in a high-load state, the first one-way valve 311 and the flow-restricting hole 312 are used to completely conduct the second ventilation pipeline 3 so that the exhaust gas in the crankcase 1 flows toward the intake pipeline of the supercharger 11. That is, when the engine is in a high-load state, the air pressure in the crankcase 1 is low, and the air pressure at the intake pipeline of the supercharger 11 is relatively high. However, due to the one-way conduction performance of the first one-way valve 311, the outside air can rarely enter the crankcase 1 through the second valve 31. However, due to the air supply pipeline 4 conveying gas into the crankcase 1, the air pressure in the crankcase 1 increases, which causes the exhaust gas in the crankcase 1 to flow into the intake pipeline of the supercharger 11 through the second one-way valve 511, and then enter the intake manifold 10 through the supercharger 11.

[0080] The third valve 41 includes a second plunger valve 411 , and the second plunger valve 411 is disposed on the gas supply pipeline 4 .

[0081] In the embodiment of the present application, when the engine is in a low-load state, the air pressure in the crankcase 1 is relatively high, and the air pressure at the intake pipe between the throttle 14 and the supercharger 11 is relatively low. At this time, the pressure difference generated between the crankcase 1, the throttle 14 and the intake pipe between the supercharger 11 can cause the second plunger valve 411 to close in the reverse direction, thereby making the air supply pipe 4 blocked.

[0082] See also Figure 3 When the engine is in a high-load state, the air pressure in the crankcase 1 is low, and the air pressure at the intake pipe between the throttle 14 and the supercharger 11 is high. At this time, the pressure difference between the crankcase 1, the throttle 14 and the intake pipe between the supercharger 11 can make the second plunger valve 411 conductive, and then make the air supply pipe 4 conductive.

[0083] The third valve 41 may further include a second one-way valve 412. The second one-way valve 412 is located between the crankcase 1 and the second plunger valve 411 and is arranged on the air supply pipeline 4, wherein the flow direction of the second one-way valve 412 is from the intake pipeline between the throttle 14 and the supercharger 11 to the crankcase 1.

[0084] In a possible implementation, the crankcase ventilation system may further include a first oil-gas separation module 5, the two ends of which are respectively connected to the crankcase 1 and the first ventilation duct 2, for preventing the oil carried in the exhaust gas in the crankcase 1 from entering the first ventilation duct 2.

[0085] In one possible implementation, the crankcase ventilation system may further include a second oil-gas separation module 6, which is respectively connected to the crankcase 1 and the second ventilation duct 3, and is used to prevent the oil carried in the exhaust gas in the crankcase 1 from entering the second ventilation duct 3.

[0086] An embodiment of the present application also provides a vehicle, which includes any one of the above-mentioned crankcase ventilation systems.

[0087] The technical solution provided by the embodiments of the present application includes at least the following beneficial effects:

[0088] An embodiment of the present application provides a crankcase ventilation system, which includes a crankcase 1, a first ventilation pipeline 2, a second ventilation pipeline 3 and an air supply pipeline 4.

[0089] When the engine is in a low-load state, the air pressure in the crankcase 1 is a relatively high positive pressure, and the air pressure at the position of the intake manifold 10 connected to the first ventilation line 2 is a negative pressure. At this time, the first valve 21 is opened, and the first ventilation line 2 is connected. Under the action of the pressure difference between the crankcase 1 and the intake manifold 10, the exhaust gas in the crankcase 1 can flow into the intake manifold 10 through the first ventilation line 2. At the same time, as the exhaust gas in the crankcase 1 is discharged, the air pressure in the crankcase 1 decreases. At this time, a small amount of outside air can enter the crankcase 1 through the second ventilation line 3 to dilute the exhaust gas in the crankcase 1 and squeeze a part of the exhaust gas in the crankcase 1 into the intake manifold 10, thereby reducing the influence of the exhaust gas on the engine oil in the crankcase 1 and increasing the service life of the engine oil.

[0090] When the engine is in a high load state, the air pressure in the crankcase 1 is a relatively low positive pressure or even a negative pressure. Since the supercharger 11 starts to work, the air pressure at the intake pipe of the supercharger 11 is relatively low, and the air pressure at the intake pipe between the throttle 14 and the supercharger 11 is relatively high positive pressure. At this time, the second valve 31 is opened, the second ventilation pipe 3 is connected, the third valve 41 is opened, and the air supply pipe 4 is connected. The air at the intake pipe between the throttle 14 and the supercharger 11 can enter the crankcase 1 through the air supply pipe 4, dilute the exhaust gas in the crankcase 1, and squeeze a part of the exhaust gas into the second ventilation pipe 3, enter the intake pipe of the supercharger 11 through the second ventilation pipe 3, and then enter the intake manifold 10 through the supercharger 11 and the throttle 14, thereby reducing the influence of the exhaust gas on the engine oil in the crankcase 1 and improving the service life of the engine oil.

[0091] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A crankcase ventilation system, characterized in that: The crankcase ventilation system comprises a crankcase (1), a first ventilation pipeline (2), a second ventilation pipeline (3) and an air supply pipeline (4); The two ends of the first ventilation pipeline (2) are respectively connected to the crankcase (1) and the intake manifold (10) of the engine; the first ventilation pipeline (2) is provided with a first valve (21); the first valve (21) is used to open the first ventilation pipeline (2) when the engine is in a low load state, and to close the first ventilation pipeline (2) when the engine is in a high load state; The two ends of the second ventilation pipeline (3) are respectively connected to the crankcase (1) and the intake pipeline of the supercharger (11) of the engine; the second ventilation pipeline (3) is provided with a second valve (31); the second valve (31) is used to limit the flow of gas flowing in the second ventilation pipeline (3) when the engine is in a low-load state, and to completely open the second ventilation pipeline (3) when the engine is in a high-load state; The two ends of the air supply pipeline (4) are respectively connected to the crankcase (1), the throttle valve (14) of the engine and the intake pipeline between the supercharger (11); a third valve (41) is provided on the air supply pipeline (4); the third valve (41) is used to close the air supply pipeline (4) when the engine is in a low load state, and to open the air supply pipeline (4) when the engine is in a high load state; Wherein, the second valve (31) comprises a first one-way valve (311) and a flow limiting hole (312); The first one-way valve (311) is arranged on the second ventilation pipeline (3), the flow direction of the first one-way valve (311) is from the crankcase (1) to the intake pipeline of the supercharger (11), and the position of the flow restriction hole (312) corresponds to the position of the first one-way valve (311); When the engine is in a low-load state, the first one-way valve (311) is used to partially cut off the air flowing from the intake pipeline of the supercharger (11) into the second ventilation pipeline (3), and the flow-limiting hole (312) is used to conduct the remaining air that is not cut off by the first one-way valve (311); When the engine is in a high-load state, the first one-way valve (311) and the flow-limiting hole (312) are used to completely open the second ventilation pipeline (3) so that the exhaust gas in the crankcase (1) flows toward the intake pipeline of the supercharger (11).

2. The crankcase ventilation system according to claim 1, characterized in that The crankcase (1) is respectively connected to a first end of a first built-in channel (121) of a cylinder head (12) of the engine and a first end of a second built-in channel (122) of the cylinder head (12); the second end of the first built-in channel (121) of the cylinder head (12) is connected to a first end of a third built-in channel (131) of a valve chamber cover (13) of the engine; the second end of the second built-in channel (122) of the cylinder head (12) is connected to a first end of a fourth built-in channel (132) of the valve chamber cover (13); the second end of the third built-in channel (131) of the valve chamber cover (13) is connected to the first ventilation pipeline (2); and the second end of the fourth built-in channel (132) of the valve chamber cover (13) is connected to the second ventilation pipeline (3).

3. The crankcase ventilation system according to claim 1, characterized in that: The crankcase ventilation system further comprises a first oil-gas separation module (5), the two ends of which are respectively connected to the crankcase (1) and the first ventilation pipeline (2), and are used to prevent the oil carried in the exhaust gas in the crankcase (1) from entering the first ventilation pipeline (2).

4. The crankcase ventilation system according to claim 1, characterized in that The first valve (21) comprises a first plunger valve, and the first plunger valve is arranged on the first ventilation pipeline (2).

5. The crankcase ventilation system according to claim 1, characterized in that The cross-sectional area of ​​the flow limiting hole (312) is smaller than a preset value.

6. The crankcase ventilation system according to claim 5, characterized in that The crankcase ventilation system further comprises a second oil-gas separation module (6), the two ends of which are respectively connected to the crankcase (1) and the second ventilation pipeline (3), and are used to prevent the oil carried in the exhaust gas in the crankcase (1) from entering the second ventilation pipeline (3).

7. The crankcase ventilation system according to claim 1, characterized in that The third valve (41) comprises a second plunger valve (411), and the second plunger valve (411) is arranged on the gas supply pipeline (4).

8. The crankcase ventilation system according to claim 7, characterized in that The third valve (41) further comprises a second one-way valve (412); The second one-way valve (412) is located between the crankcase (1) and the second plunger valve (411), and is arranged on the air supply pipeline (4); the flow direction of the second one-way valve (412) is from the air intake pipeline between the throttle valve (14) and the supercharger (11) toward the crankcase (1).

9. A vehicle, characterized in that: The vehicle comprises a crankcase ventilation system according to any one of claims 1-8.

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