Crankcase ventilation system and methanol engine

Abstract

The invention provides a crankcase ventilation system and a methanol engine. The crankcase ventilation system comprises an air supplementing chamber, an air blow-by chamber, an air inlet pipeline and a first pipeline. An air supply chamber and a blow-by chamber are formed in the crankcase; the gas inlet pipeline is communicated between external gas and the supercharger; the first pipeline is sequentially communicated with the supercharger, the gas supplementing chamber and the gas blow-by chamber, so that external gas forms supplemented gas to enter the gas supplementing chamber and the gas blow-by chamber; and a first one-way valve is arranged between the air supply chamber and the blow-by chamber, so that the supplied air can only flow to the blow-by chamber from the air supply chamber. The air supply chamber supplies air through exhaust of the pressurizing chamber, the supplied air is fresh air containing little water vapor, the blow-by air containing a large amount of water vapor in the blow-by chamber cannot enter the air supply chamber, the fresh air containing little water vapor always exists in the air supply chamber, and due to the fact that the water content of the air in the air supply chamber is low, even if the external temperature is very low, the air supply chamber can still supply air to the air supply chamber. And the fresh gas cannot reach the dew point temperature and cannot be condensed into water drops, so that parts in the gas supply chamber cannot be rusted, and engine oil cannot be emulsified.

Description

Technical Field

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

[0002] A methanol engine is an engine that uses methanol as fuel. The gas after the combustion of methanol contains water vapor accounting for up to 23%. The water vapor produced by the combustion of methanol relative to diesel or gasoline fuel is 76% more than that of gasoline or diesel, and the dew point temperature is about 63°C. In an ammonia fuel engine, the water vapor in the gas after the combustion of ammonia fuel accounts for up to 30%, which is 124% more than that of gasoline or diesel. In a hydrogen fuel engine, the water vapor in the gas after the combustion of hydrogen fuel accounts for up to 33%, and the dew point temperature is above 65°C.

[0003] Regarding methanol engines, if no measures are taken, the crankcase gas temperature or the wall temperature of the parts will condense into water after it is lower than the dew point temperature of 63°C. Market feedback and laboratory tests have confirmed that the inner wall of the cylinder head cover and the valve mechanism in the cylinder head cover of the methanol engine will produce oil emulsions due to condensed water. In serious cases, the oil emulsions will even block the oil-gas pre-separation mechanism channel, causing the crankcase pressure to increase and the engine to shut down for protection and fail to work; and the condensed water will also cause the valve mechanism in the cylinder head cover and other parts to rust and damage, causing oil pollution; in addition, since the crankcase blowby containing more water vapor will enter the intercooler through the supercharger, in cold winter areas, the gas channel in the intercooler will freeze, the air duct will be blocked, and even the intercooler will be frozen and cracked.

[0004] Therefore, how to solve the problem that water vapor in the crankcase condenses into water, causing rust and damage to parts such as the valve mechanism in the cylinder head cover and causing emulsification of the engine oil is a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0005] In view of this, the present application provides a crankcase ventilation system and a methanol engine to solve the problem that water vapor in the crankcase condenses into water, causing rust and damage to components such as the valve mechanism in the cylinder head cover and causing emulsification of the engine oil.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A crankcase ventilation system comprising:

[0008] A charge air chamber and a blowby air chamber are formed in the crankcase;

[0009] An air intake pipeline, connected between external gas and the supercharger;

[0010] A first pipeline is connected to the supercharger, the air-filling chamber, and the blow-by chamber in sequence, so that external gas forms air-filling and enters the air-filling chamber and the blow-by chamber;

[0011] Wherein, a first one-way valve is arranged between the air-supplementing chamber and the blow-by air chamber, so that the air-supplementing chamber can only flow from the air-supplementing chamber to the blow-by air chamber.

[0012] Optionally, a second pipeline is further included, and two ends of the second pipeline are respectively connected to the air replenishment chamber and the air intake pipeline.

[0013] Optionally, a second one-way valve is provided on the second pipeline, and the second one-way valve is opened under low-load conditions of the engine and closed under high-load conditions of the engine.

[0014] Optionally, a third pipeline is also included, which is connected to the supercharger, the intercooler, the throttle valve, the intake manifold, the combustion chamber, the blowby chamber, the separation device and the intake pipeline in sequence.

[0015] Optionally, the third pipeline between the separation device and the air intake pipeline is divided into a first part and a second part, and the second part is arranged between the first part and the separation device;

[0016] The separation device is in communication with the intake manifold via the second portion and a first branch, and the first branch is disposed between the intake manifold and the second portion.

[0017] Optionally, a third one-way valve is provided on the first branch, and the third one-way valve is opened under low-load conditions of the engine and closed under high-load conditions of the engine.

[0018] Optionally, a fourth one-way valve is provided on the first part, and the fourth one-way valve is closed under low-load conditions of the engine and opened under high-load conditions of the engine.

[0019] Optionally, it also includes an air filter arranged at the air inlet of the air intake pipe.

[0020] A methanol engine, comprising the crankcase ventilation system of any one of the above items;

[0021] The air replenishment chamber is composed of a cylinder head, an oil return sealing structure, a cylinder head cover, a cylinder head and a cylinder head cover gasket, a valve oil seal, a valve, a valve guide, a partition structure, and the first one-way valve;

[0022] The blow-by chamber is composed of a cylinder head, the oil return seal structure, a cylinder body, an oil pan, a lower surface of a piston, a gear chamber cavity, the partition structure, and the first one-way valve;

[0023] The partition structure includes a camshaft seat cover, a partition plate sealed between the camshaft seat cover and the cylinder head cover, and the first one-way valve is arranged in a one-way valve installation hole on the camshaft seat cover;

[0024] The oil return sealing structure is separated between the air replenishment chamber and the blow-by chamber so that the engine oil in the air replenishment chamber can return to the oil pan.

[0025] Optionally, the oil return sealing structure includes an S-shaped oil storage bend or a fifth one-way valve arranged in the oil channel.

[0026] In the crankcase ventilation system and methanol engine provided by the present application, the air replenishment chamber and the blow-by chamber are formed in the crankcase; wherein the air replenishment chamber is replenished with high-temperature and high-pressure gas discharged from the supercharger chamber, and the replenished gas is fresh gas with little water vapor, and the first pipeline between the air replenishment chamber and the blow-by chamber is provided with a first one-way valve, so that the blow-by gas in the blow-by chamber containing a large amount of water vapor will not enter the air replenishment chamber, and the air replenishment chamber is always fresh gas with little water vapor. Since the water content of the gas in the air replenishment chamber is small, even when the outside temperature is very low and far away from the heating source, the dew point temperature of the fresh gas is very low, and it will not condense into water droplets like the outside air, so that the parts in the air replenishment chamber will not rust and cause the engine oil to emulsify. Moreover, the air replenishment chamber is all fresh gas, and when the temperature is low, the temperature of the parts in the air replenishment chamber can be reduced, and the service life of the parts can be increased. In addition, the gas with less water vapor in the air replenishment chamber is transported to the blow-by chamber, which can reduce the dew point temperature of the blow-by gas in the blow-by chamber, so that the parts in the blow-by chamber will not rust and cause the engine oil to emulsify. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0028] Figure 1 It is a crankcase ventilation model in the prior art;

[0029] Figure 2 is the dew point temperature in the prior art;

[0030] Figure 3 A crankcase ventilation model under low load provided for an embodiment of the present application;

[0031] Figure 4 A crankcase ventilation model under high load provided by an embodiment of the present application;

[0032] Figure 5The dew point temperature provided in the embodiments of the present application;

[0033] Figure 6 A partial cross-sectional view of a methanol engine at a first angle provided in an embodiment of the present application;

[0034] Figure 7 A partial cross-sectional view of a methanol engine from a second angle provided in an embodiment of the present application;

[0035] Figure 8 A partial cross-sectional view of a methanol engine from a third angle provided in an embodiment of the present application;

[0036] Fig. 9 A schematic diagram of a cylinder head cover provided in an embodiment of the present application;

[0037] Fig.10 A schematic diagram of a camshaft seat cover provided in an embodiment of the present application;

[0038] Fig.11 A partial cross-sectional view of a methanol engine from a fourth angle provided in an embodiment of the present application;

[0039] Fig.12 A schematic diagram of a cylinder head and a cylinder head cover gasket provided in an embodiment of the present application;

[0040] Fig.13 A partial cross-sectional view of a methanol engine from a fifth angle provided in an embodiment of the present application;

[0041] Fig.14 Provided in an embodiment of the present application is a structural diagram of an S-shaped oil storage bend.

[0042] exist Figure 1-Figure 14 middle:

[0043] 1. The first pipeline;

[0044] 11. Supercharger; 12. Air supply chamber; 13. Blow-by chamber; 14. Air intake pipeline; 15. First one-way valve; 16. Air filter;

[0045] 2. Second pipeline;

[0046] 21. Second one-way valve;

[0047] 3. The third pipeline;

[0048] 31. Intercooler; 32. Throttle valve; 33. Intake manifold; 34. Combustion chamber; 35. Separation device; 351. Pre-separator; 352. Main separator; 36. First part; 361. Fourth non-return valve; 37. Second part;

[0049] 4. The first branch;

[0050] 41. The third one-way valve;

[0051] 501. Cylinder head cover; 502. Inner surface of cylinder head cover; 503. Valve oil seal; 504. Valve; 505. Valve guide; 506. Cylinder head and cylinder head cover gasket; 507. Piston; 508. Lower surface of piston; 509. Cylinder block; 510. Inner cavity of cylinder block; 511. Cylinder liner; 512. Combustion chamber blowby; 513. Piston ring; 514. Upper surface of cylinder head; 515. Partition structure; 516. Camshaft seat cover; 517. Partition plate; 518. Gear chamber cavity; 519. One-way valve mounting hole; 520. S-shaped oil storage bend. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] See Figure 1 and Figure 2 In the crankcase ventilation system of the methanol engine in the prior art, air passes through the air filter and then enters the supercharger 11 to become high-temperature and high-pressure gas. After being cooled by the intercooler, the temperature is reduced. One way enters the crankcase through the high-pressure air supply pipe, and the other way passes through the throttle and then enters the combustion chamber through the intake manifold. In the combustion chamber, it is mixed with methanol and burned. Most of the gas generated after combustion is discharged into the atmosphere through the exhaust system; however, a small part of the gas penetrates into the engine crankcase through the gap between the piston, the piston ring and the cylinder hole, and finally enters the intake manifold before the supercharger 11 after passing through the oil-gas pre-separation mechanism and the oil-gas fine separation mechanism. In the ventilation system, a high-pressure air supply pipe is used to take air from the back of the intercooler to supply air to the crankcase, hoping to reduce the dew point temperature of the gas in the crankcase. However, the gas pressure after the intercooler 31 varies greatly with the working conditions (usually with a range of several hundred kilopascals), and the amount of air supply in the crankcase is difficult to control. In addition, under low-load conditions, the pressure after the intercooler is small and the amount of air supply is small, resulting in the dew point temperature of the gas in the crankcase being almost unchanged; at this time, the crankcase gas temperature is low, and water vapor is more likely to condense into small water droplets, emulsifying the engine oil. In addition, the crankcase pressure and the amount of air supply are inversely proportional. In order to meet the crankcase pressure requirements, the prior art uses an air supply pipe with an aperture of about 1 mm, and controls the maximum air supply amount by the small hole diameter, so that the crankcase pressure meets the requirements while obtaining an air supply of about 20%; if the air supply amount is increased by increasing the aperture of the air supply pipe, the crankcase pressure will become positive pressure, exceeding the regulatory requirements. While ensuring the crankcase pressure, the amount of air replenishment will be limited and the crankcase gas dew point temperature can only be reduced by 3°C at most.

[0054] It should be noted that the oil-gas pre-separation mechanism is arranged on the cylinder head cover, and part of the gas (blow-by gas) after combustion in the combustion chamber flows through the piston in sequence: cylinder crankcase → channel between cylinder head and cylinder block → cylinder head cover on the upper part of the cylinder head → oil-gas pre-separation mechanism → pipeline → oil-gas fine separation mechanism → intake pipe before supercharger → supercharger → intercooler after supercharger → intake manifold → combustion chamber. The cylinder head cover is far away from the engine body, the outside of the cylinder head cover faces the wind and is in contact with the atmosphere, the temperature is very low, and the inside of the cylinder head cover is hot and humid blow-by gas with high water and oil content. The hot and humid blow-by gas condenses into droplets when it is cold, corrodes parts such as valve distribution and brake mechanism, produces emulsions, and even blocks the pre-separation channel.

[0055] The crankcase gas dew point temperature is about 60°C, see Figure 2 The dew point temperature is very high, especially when the wall temperature of the parts does not reach 60°C, the water vapor in the crankcase gas or the gas contacting the wall will condense into small water droplets, emulsifying the engine oil and causing the parts in the cylinder head cover to rust; if the crankcase gas temperature or the wall temperature of the parts is lower than the dew point temperature, the faster the water condenses and the more serious the emulsification will be.

[0056] When the engine is running at low speed and low load: the combustion chamber pressure is small, the blowby volume is small; the gas pressure after the supercharger is small, the air supply pipe aperture is small, and the air supply volume is very small; at this time, the throttle opening is very small, and the intake manifold is close to atmospheric pressure; only the pumping function of the oil-gas separation mechanism is relied on to generate negative pressure, pump the crankcase gas into the intake manifold, and keep the crankcase at negative pressure. However, in cold areas, when the engine runs at low load for a long time, it is difficult to heat the inner wall of the curved pipe, the separator, the cylinder head cover, etc. and the crankcase gas inside to 60°C. The crankcase blowby containing more water vapor enters the intercooler through the supercharger. The water vapor will condense into water when passing through the intercooler. After the engine is stopped, it will gather at the bottom of the ventilation pipe in the intercooler, and then freeze to block the ventilation pipe, causing the engine to fail to start, the intercooler to rupture, and other faults.

[0057] When the engine is running at high speed and high load: the combustion chamber pressure is high and the blowby gas volume is large; the gas pressure after the supercharger is high. In order to maintain the crankcase pressure, a small-diameter air supply pipe is used with an air supply volume of about 20L / min; the throttle opening is large, and the negative pressure of the intake manifold is about -5KPa~-3KPa. The crankcase gas is mainly sucked into the intake manifold by the negative pressure in the intake manifold, and the crankcase is kept at a negative pressure between -5KPa and 0KPa.

[0058] Therefore, the system has problems such as oil emulsification, rust on internal parts of the cylinder head cover, and water vapor freezing in the intercooler blocking the pipes and causing them to rupture.

[0059] like Figure 3-Figure 7 As shown, an embodiment of the present application provides a crankcase ventilation system.

[0060] First, the crankcase ventilation system includes an air supply chamber 12, a blow-by chamber 13, an intake pipe 14 and a first pipe 1; wherein the air supply chamber 12 and the blow-by chamber 13 are formed in the crankcase; the intake pipe 14 is connected between the external gas and the supercharger 11; the first pipe 1 is connected to the supercharger 11, the air supply chamber 12, and the blow-by chamber 13 in sequence, so that the external gas forms an air supply and enters the air supply chamber 12 and the blow-by chamber 13; wherein a first one-way valve 15 is arranged between the air supply chamber 12 and the blow-by chamber 13, so that the air supply can only flow from the air supply chamber 12 to the blow-by chamber 13, and prevent the gas in the blow-by chamber 13 from diffusing to the air supply chamber 12. The air supply chamber 12 and the blow-by chamber 13 are independent chambers, and the air supply chamber 12 is a low temperature chamber and the blow-by chamber 13 is a high temperature chamber. The first one-way valve 15 between the air replenishment chamber 12 and the blowby chamber 13 can not only isolate the two, preventing the gas with high water content in the blowby chamber 13 from flowing to the air replenishment chamber 12, thereby increasing the water content in the air replenishment chamber 12; it can also play the role of air replenishment distribution to the air replenishment chamber 12, and can accurately blow air to a specific direction of the blowby chamber 13. It should be noted that the gas mentioned in this article is air, but it is not limited to this. The specific type of the gas is as long as the gas is in the surrounding environment of the crankcase and can meet the use requirements. In addition, compared with the prior art of taking air from the back of the intercooler, the present application takes air from the back of the supercharger 11 and before the intercooler 31, reducing the water vapor content passing through the intercooler 31, and can reduce the risk of the intercooler 31 pipeline being blocked and ruptured due to condensed water freezing.

[0061] It can be seen that in the crankcase ventilation system provided by the present application, the air replenishment chamber 12 and the blow-by chamber 13 are formed in the crankcase; wherein the air replenishment chamber 12 is replenished with high-temperature and high-pressure gas discharged from the supercharger chamber, and the replenished gas is fresh gas with little water vapor, and the first pipeline 1 between the air replenishment chamber 12 and the blow-by chamber 13 is provided with a first non-return valve 15, which can prevent the blow-by gas in the blow-by chamber 13 containing a large amount of water vapor from entering the air replenishment chamber 12, and the air replenishment chamber 12 is always fresh gas with little water vapor. Since the water content of the gas in the air replenishment chamber 12 is small, even when the outside temperature is very low and far away from the heating source, the dew point temperature of the fresh gas is also very low, almost the same as the dew point temperature of the outside air, and will not condense into water droplets, thereby preventing the parts in the air replenishment chamber 12 from rusting and causing the engine oil to emulsify. In addition, the air replenishment chamber 12 is full of fresh gas, and when the temperature is low, the temperature of the parts in the air replenishment chamber 12 can be reduced, thereby increasing the service life of the parts. In addition, the gas with less water vapor in the air replenishment chamber 12 is transported to the blowby chamber 13 to dilute the water vapor concentration in the blowby gas in the blowby chamber 13, which can reduce the dew point temperature of the blowby gas in the blowby chamber 13, thereby preventing the parts in the blowby chamber 13 from rusting and causing the engine oil to emulsify.

[0062] In the specific implementation, it also includes a second pipeline 2, and the two ends of the second pipeline 2 are connected to the air replenishment chamber 12 and the air intake pipeline 14 respectively. The air replenishment chamber 12 is replenished with air through the air intake pipeline 14, and the replenished gas is fresh gas with little water vapor. Under low temperature conditions, the temperature of the parts in the air replenishment chamber 12 can be reduced, and the service life of the parts can be increased. In addition, the gas with less water vapor in the air replenishment chamber 12 is transported to the blowby chamber 13, diluting the water vapor concentration in the blowby gas in the blowby chamber 13, which can reduce the dew point temperature of the blowby gas in the blowby chamber 13, thereby preventing the parts in the blowby chamber 13 from rusting and causing the engine oil to emulsify. And compared with the situation where the air replenishment chamber 12 is replenished with air only from the supercharger 11, the air replenishment of the air replenishment chamber 12 by the intake pipe can firstly ensure the intake volume, and secondly, there is one more choice for the air replenishment method of the air replenishment chamber 12, so that the ventilation system has the flexibility to switch under different working conditions, and the air replenishment volume is easier to control.

[0063] In specific implementation, a second one-way valve 21 is provided on the second pipeline 2, and the second one-way valve 21 is opened under low-load conditions of the engine, and is closed under high-load conditions of the engine. The second one-way valve 21 can prevent the gas in the air replenishment chamber 12 from flowing back to the intake pipeline 14. The opening pressure of the second one-way valve 21 needs to ensure that the air replenishment chamber 12 can be replenished in time, and the air replenishment in the air replenishment chamber 12 can be fully replenished in coordination with the air replenishment in the first pipeline 1. At the same time, the reverse leakage of the second one-way valve 21 should be within a reasonable range.

[0064] In a specific implementation, it also includes a third pipeline 3, which is connected to the supercharger 11, the intercooler 31, the throttle 32, the intake manifold 33, the combustion chamber 34, the blowby chamber 13, the separation device 35 and the intake pipeline 14 in sequence. In the engine, the gas flow in the crankcase is better controlled, and the engine is ensured to operate effectively under various working conditions. Among them, the supercharger 11 (such as a turbocharger 11 or a mechanical supercharger 11) is used to increase the intake pressure, thereby increasing the power output of the engine; the intercooler 31 cools the high-temperature compressed air coming out of the supercharger 11 to increase the air density and thus improve the combustion efficiency; the throttle 32 controls the amount of air entering the engine combustion chamber 34 to ensure the mixing ratio and combustion performance of the gas in the combustion chamber 34; the intake manifold 33 guides the gas output of the throttle 32 and distributes the gas evenly into each cylinder of the combustion chamber 34; the fuel in the combustion chamber 34 is mixed with the gas in the intake manifold 33 and burns together; the combustion process The chemical energy is converted into heat energy, and then converted into mechanical energy through the piston and connecting rod mechanism, driving the crankshaft to rotate, thereby generating the power output of the engine. A large amount of gas is generated during the combustion process, part of which is discharged into the atmosphere, and part of which enters the blow-by chamber 13 as blow-by gas; the separation device 35 separates the unburned fuel and lubricating oil vapor contained in the blow-by chamber 13, removes oil mist or oil droplets (helps to reduce carbon deposits and emission pollutants in the combustion chamber 34), and then the outflowing gas enters the intake manifold and participates in the circulation of the third pipeline 3 again or enters the intake manifold 33 to continue to participate in the work of the combustion chamber 34. This pipeline can ensure that the gas is effectively utilized and reduce emissions at the same time.

[0065] In specific implementation, the third pipeline 3 between the separation device 35 and the intake pipeline 14 is divided into a first part 36 and a second part 37, and the second part 37 is arranged between the first part 36 and the separation device 35; the separation device 35 is connected with the intake manifold 33 through the second part 37 and the first branch 4, and the first branch 4 is arranged between the intake manifold 33 and the second part 37. The first part 36 and the first branch 4 are branches of the second part 37, that is, the exhaust gas of the separation device 35 can be divided into two paths after passing through the second part 37, one path enters the intake manifold and continues to participate in the circulation of the third pipeline 3, and the other path enters the intake manifold 33. When the intake manifold 33 needs more intake air, the air volume can be supplemented, which can ensure the effective use of gas and reduce emissions.

[0066] In specific implementation, a third one-way valve 41 is provided on the first branch 4, and the third one-way valve 41 is opened under low-load conditions of the engine, and is closed under high-load conditions of the engine. When the engine is under low-load conditions, the gas pressure of the second part 37 is greater than the opening pressure of the third one-way valve 41, the third one-way valve 41 is opened, the first branch 4 is connected, and the gas can be replenished into the intake manifold 33, and the third one-way valve 41 is provided to effectively prevent the gas in the intake manifold 33 from flowing back. It should be noted that the third one-way valve 41 is a PCV valve (Positive Crankcase Ventilation Valve), which adjusts the opening degree of the valve by controlling the spring and the external pressure difference to control the gas flow from the blowby chamber 13 in the crankcase to the intake manifold 33. When the engine is running, the pressure of the blowby chamber 13 will prompt the PCV valve to open, allowing the gas to flow to the intake manifold 33.

[0067] In a specific implementation, a fourth one-way valve 361 is provided on the first part 36. The fourth one-way valve 361 is closed under low-load conditions of the engine and opened under high-load conditions of the engine. When the engine is under high-load conditions, the gas pressure of the second part 37 is greater than the opening pressure of the fourth one-way valve 361, the fourth one-way valve 361 is opened, the first part 36 is turned on, and the gas can enter the intake pipe 14. Moreover, the fourth one-way valve 361 can effectively prevent the gas in the intake pipe 14 from flowing back.

[0068] In specific implementation, the separation device 35 includes a pre-separator 351 and a main separator 352, and the pre-separator 351 is arranged between the main separator 352 and the blow-by chamber 13. The pre-separator 351 and the main separator 352 sequentially separate the exhaust gas (oil mist mixture) discharged from the blow-by chamber 13 from oil and gas, so that the separated gas enters the intake manifold 33 again through the first branch 4, or enters the intake pipe 14 through the first part 36.

[0069] In addition, regarding the opening and closing of the first one-way valve 15, the gas pressure in the air replenishment chamber 12 is greater than the opening pressure of the first one-way valve 15, the first one-way valve 15 is opened, the air replenishment can enter the blowby chamber 13, and the backflow of the blowby gas can be effectively prevented by the setting of the fourth one-way valve 361. The structural design of the first one-way valve 15 can be specifically designed by those skilled in the art according to actual needs, so as to realize the control of the one-way flow of the gas.

[0070] In a specific implementation, an air filter 16 is also included which is connected to the air inlet of the air intake line 14. The air filter 16 can filter the gas entering the air intake line 14 to prevent dust particles in the gas from entering the crankcase ventilation system, thereby causing problems such as wear and blockage of parts in the crankcase ventilation system.

[0071] In specific implementation, the first pipeline 1 between the supercharger 11 and the air supply chamber 12 is a high-pressure air supply pipeline. The diameter of the high-pressure air supply pipeline determines the intake volume. The intake volume not only needs to meet the crankcase pressure maintained at -5KPa-0KPa, but also needs to meet the requirement of reducing the dew point temperature of the gas in the blowby chamber 13 under both high load and low load.

[0072] In specific implementation, by providing a large-flux air supply pipe, a second one-way valve 21, a fourth one-way valve 361, a PCV valve, and a first branch 4 connected to the intake manifold 33 via the PCV valve, and increasing the diameter of the high-pressure air supply pipe and other measures, especially by inhaling air through the intake manifold 33, the ventilation system increases the high-flux air supply while increasing the amount of high-pressure air supply, which can reduce the gas dew point temperature of the blowby chamber 13 and prevent condensation of water vapor in the blowby gas and emulsification of the engine oil.

[0073] The crankcase ventilation system provided in the present application can ensure the crankcase pressure load regulatory requirements while replenishing air in the blowby chamber 13 through the air replenishment chamber 12, thereby reducing the dew point temperature of the blowby gas in the blowby chamber 13 and preventing the gas in the pipeline from emulsifying and freezing.

[0074] Based on the above crankcase ventilation system, the present application embodiment also provides a methanol engine, please refer to Figure 6-Figure 14 The methanol engine includes the above crankcase ventilation system; the air supply chamber 12 is composed of a cylinder head (upper surface), an oil return sealing structure, a cylinder head cover 501 (inner surface), a cylinder head and a cylinder head cover gasket 506, a valve oil seal 503, a valve 504, a valve guide 505, a partition structure 515, and a first check valve 15. The air supply chamber 12 is an independent and closed space; the blowby chamber 13 is composed of a cylinder head (lower surface), an oil return sealing structure, a cylinder body 509 (inner cavity), an oil pan ( The methanol engine is composed of an inner cavity, a piston lower surface 508, a gear chamber cavity 518, a partition structure 515, and a first one-way valve 15; the partition structure 515 includes a camshaft seat cover 516, a partition plate 517 sealed between the camshaft seat cover 516 and the cylinder head cover 501, and the first one-way valve 15 is arranged in a one-way valve mounting hole 519 on the camshaft seat cover 516; the return oil sealing structure is separated between the air replenishment chamber 12 and the blowby chamber 13, so that the oil in the air replenishment chamber 12 can return to the oil pan. Since the methanol engine has the above-mentioned crankcase ventilation system, the beneficial effects brought by the crankcase ventilation system to the methanol engine can be found in the above content, which will not be repeated here. In order to help understand the present application, the inner surface 502 of the cylinder head cover, the piston 507, the cylinder body cavity 510, the cylinder liner 511, the combustion chamber blowby 512, the piston ring 513, and the cylinder head upper surface 514 are shown in the figure.

[0075] In a specific implementation, the oil return sealing structure includes an S-shaped oil storage bend 520 or a fifth one-way valve disposed in the oil passage, see Fig.13 , Fig.14The oil return sealing structure is an S-shaped oil storage bend 520. It should be noted that the S-shaped oil storage bend 520 is filled with engine oil in the first bending position close to the air replenishment chamber 12. The engine oil isolates the air replenishment chamber 12 from the blowby chamber 13. One end of the S-shaped oil storage bend 520 is connected to the air replenishment chamber 12, and the other end is connected to the blowby chamber 13. The bending point of the first bending position of the S-shaped oil storage bend 520 closer to the air replenishment chamber 12 is taken as the reference line. When the pressure of the air replenishment chamber 12 is greater than the pressure of the blowby chamber 13, the vertical length between the liquid level position of the engine oil and the reference line is h, ρgh>△p; when the pressure of the air replenishment chamber 12 is less than the pressure of the blowby chamber 13, the vertical length between the liquid level position of the engine oil and the reference line is H, satisfying ρgH>△p. Under this design condition, the excess engine oil in the air replenishment chamber 12 can return to the oil pan smoothly. At the same time, the engine oil is always stored to achieve sealing; wherein △p is the pressure difference between the air replenishment chamber 12 and the blowby chamber 13.

[0076] In specific implementation, the separation device 35 is integrated on the cylinder body, and its intake and outlet passages are both arranged on the cylinder body, and a heating water channel is arranged; the intake and outlet passages of the main separator 352 are both arranged on the cylinder body, and the outlet passage passes through the PCV valve and enters the cylinder head air passage and then enters the intake manifold 33, and is connected to the intake manifold before the supercharger 11 through the fourth one-way valve 361.

[0077] In specific implementation, when the engine is at low speed and low load, the working process of the crankcase ventilation system is as follows: the throttle valve 32 is opened slightly, the intake manifold 33 is negatively charged between -80kPa and 0kPa, and the blowby gas in the blowby chamber 13 is sucked into the intake manifold 33 after passing through the pre-separator 351, the main separator 352 and the PCV valve arranged on the cylinder body, and then enters the combustion chamber 34 to participate in combustion, and is finally discharged into the atmosphere. At this time, the blowby chamber 13 is under negative pressure, and the air replenishment chamber 12 is under negative pressure. The fresh gas in the intake manifold is sucked into the air replenishment chamber 12 through the second one-way valve 21; at the same time, the high-pressure and high-temperature fresh gas before the intercooler 31 after the supercharger 11 is pressed into the air replenishment chamber 12, and the fresh gas from the two places passes through the air replenishment chamber 12 and enters the blowby chamber 13. The entry of the set amount of fresh gas reduces the dew point temperature of the gas in the blowby chamber 13 by about 25°C. For details, see Figure 5The blow-by chamber 13 is close to the cylinder head combustion chamber 34 and the cylinder liner of the cylinder block, as well as the engine water jacket, which makes the gas temperature in the blow-by chamber 13 far exceed the dew point temperature, forming no conditions for condensation into small water droplets, so that the parts in the blow-by chamber 13 will not rust and the engine oil will not emulsify. In addition, since the throttle valve 32 has a small opening, the pressure in the intake manifold is close to the atmospheric pressure, the negative pressure in the intake manifold 33 is very large, the PCV valve is opened, and the fourth one-way valve 361 is closed, and the fresh gas enters the blow-by chamber 12 from the large-flux air supply pipeline and then enters the blow-by chamber 13; in addition, since the boost pressure of the supercharger 11 is small, the fresh gas entering the air supply chamber 12 through the air supply pipeline after the pressure end of the supercharger 11 is relatively small, about 10%. It should be noted that the crankcase ventilation system maintains the crankcase pressure between -5KPa and 0KPa through the negative pressure of the intake manifold 33, the negative pressure before the pressure end of the supercharger 11, the PCV pressure regulating valve and the large-flow air supply, and the positive pressure air supply after the pressure end of the supercharger 11.

[0078] When the engine is at high speed and high load, the working process of the crankcase ventilation system is: the throttle 32 is opened widely, the pressure after the pressure end of the supercharger 11 is positive, the intake manifold 33 is positive, and the PCV valve is in a closed state; the pressure before the pressure end of the supercharger 11 is negative, the intake manifold is negative, which is less than the crankcase pressure, and the second one-way valve 21 is closed; the blowby gas in the blowby chamber 13 is first sucked into the intake manifold through the pre-separator 351, the fine separator and the fourth one-way valve 361, and then enters the combustion chamber 34 through the third pipeline 3 to participate in combustion, and is finally discharged into the atmosphere. The high-pressure and high-temperature fresh gas before the intercooler 31 after the supercharger 11 is pressed into the air supply chamber 12. After passing through the air supply chamber 12, the fresh gas enters the blow-by chamber 13, diluting the water content of the blow-by gas in the blow-by chamber 13, so that the water content of the gas in the blow-by chamber 13 becomes smaller. Since the engine temperature is high in this working condition, the wall temperature around the blow-by gas is much higher than the dew point temperature of the blow-by gas, and the conditions for forming small water droplets cannot be met, so the parts in the blow-by chamber 13 will not rust and the engine oil will not emulsify. In addition, the supercharger 11 has a large boost pressure, the intake manifold 33 is positively pressurized, and the fresh gas is only supplemented through the high-pressure air supply pipeline; the pressure of the air supply chamber 12 and the blow-by chamber 13 is maintained between -5KPa and 0KPa by the negative pressure of the intake manifold.

[0079] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0080] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0081] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0082] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0083] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0084] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A crankcase ventilation system, characterized in that: include: A supplementary air chamber (12) and a blow-by air chamber (13) are formed in the crankcase; An air intake pipeline (14) connected between external gas and the supercharger (11); The first pipeline (1) is connected to the supercharger (11), the air replenishment chamber (12), and the blow-by chamber (13) in sequence, so that external gas forms air replenishment and enters the air replenishment chamber (12) and the blow-by chamber (13); A first one-way valve (15) is provided between the air supply chamber (12) and the blow-by chamber (13), so that the air supply can only flow from the air supply chamber (12) to the blow-by chamber (13).

2. The crankcase ventilation system according to claim 1, characterized in that It also comprises a second pipeline (2), the two ends of which are respectively connected to the air replenishment chamber (12) and the air intake pipeline (14).

3. The crankcase ventilation system according to claim 2, characterized in that: A second one-way valve (21) is arranged on the second pipeline (2), and the second one-way valve (21) is opened under low-load conditions of the engine and closed under high-load conditions of the engine.

4. The crankcase ventilation system according to claim 1, characterized in that The invention also comprises a third pipeline (3), wherein the third pipeline (3) is connected in sequence to the supercharger (11), the intercooler (31), the throttle valve (32), the intake manifold (33), the combustion chamber (34), the blow-by chamber (13), the separation device (35) and the intake pipeline (14).

5. The crankcase ventilation system according to claim 4, characterized in that The third pipeline (3) between the separation device (35) and the intake pipeline (14) is divided into a first part (36) and a second part (37), and the second part (37) is arranged between the first part (36) and the separation device (35); The separation device (35) is connected to the intake manifold (33) via the second portion (37) and a first branch (4), and the first branch (4) is arranged between the intake manifold (33) and the second portion (37).

6. The crankcase ventilation system according to claim 5, characterized in that A third one-way valve (41) is provided on the first branch (4), and the third one-way valve (41) is opened under low-load conditions of the engine and closed under high-load conditions of the engine.

7. The crankcase ventilation system according to claim 5, characterized in that The first part (36) is provided with a fourth one-way valve (361), and the fourth one-way valve (361) is closed under a low-load condition of the engine and opened under a high-load condition of the engine.

8. The crankcase ventilation system according to claim 1, characterized in that It also includes an air filter (16) arranged at the air inlet of the air inlet pipeline (14).

9. A methanol engine, characterized in that: A crankcase ventilation system comprising any one of claims 1 to 8; The air replenishing chamber (12) is composed of a cylinder head, an oil return sealing structure, a cylinder head cover (501), a cylinder head and a cylinder head cover gasket (506), a valve oil seal (503), a valve (504), a valve guide (505), a partition structure (515), and the first one-way valve (15); The blow-by chamber (13) is composed of a cylinder head, the oil return seal structure, a cylinder body (509), an oil pan, a piston lower surface (508), a gear chamber cavity (518), the partition structure (515), and the first one-way valve (15); The partition structure (515) comprises a camshaft seat cover (516), a partition plate (517) sealed between the camshaft seat cover (516) and the cylinder head cover (501), and the first one-way valve (15) is arranged in a one-way valve installation hole (519) on the camshaft seat cover (516); The oil return sealing structure is separated between the air replenishment chamber (12) and the blow-by chamber (13), so that the engine oil in the air replenishment chamber (12) can return to the oil pan.

10. The methanol engine according to claim 9, characterized in that: The oil return sealing structure comprises an S-shaped oil storage bend (520) or a fifth one-way valve arranged in the oil passage.

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