Crankcase negative pressure control system, crankcase negative pressure control method, and automobile

Abstract

This application provides a crankcase negative pressure control system, a crankcase negative pressure control method, and an automobile. The crankcase negative pressure control system includes a low-load operating condition circuit and a high-load operating condition circuit. An air compensation unit is equipped with a differential pressure controller, which increases the resistance to air being introduced into the crankcase, thus keeping the crankcase under negative pressure under low-load conditions. The auxiliary ventilation unit is connected at both ends to a first crankcase ducting unit and a supercharger unit, respectively. The air compensation unit is connected at both ends to a second crankcase ducting unit and a supercharger unit, respectively. The auxiliary ventilation unit and the air compensation unit work together to keep the crankcase under negative pressure under high-load conditions. When the supercharger speed is higher than its rated value, the low-load oil-gas separator and the high-load oil-gas separator can work simultaneously, drawing out a large amount of fuel vapor and water vapor from the crankcase, increasing the circulating air volume, thereby keeping the crankcase under negative pressure at all times.

Description

Technical Field

[0001] This application relates to the field of automotive technology, and in particular to a crankcase negative pressure control system, a crankcase negative pressure control method, and automobiles. Background Technology

[0002] Currently, the Qutong system design is mainly divided into two paths: the high-load condition path and the low-load condition path.

[0003] The gas flow path in the low-load operating condition is as follows: the air-fuel mixture passes through the crankcase → low-load oil-gas separator (the low-load oil-gas separator is integrated in the cylinder head cover) → PCV valve → intake manifold → combustion in the combustion chamber; fresh air passes through the air filter → cylinder head cover → crankcase; through the above process, pressure balance and air-fuel mixture replacement are achieved in the crankcase, reducing oil failure and improving oil life.

[0004] In the high-load operating condition, the gas flow path is as follows: the air-fuel mixture passes through the crankcase → high-load oil-gas separator (the high-load oil-gas separator is integrated inside the cylinder head cover) → after the air filter → turbocharger (for turbocharged models, not for naturally aspirated models) → intercooler → inside the intake manifold → combustion in the combustion chamber; there is no fresh air supply under this condition.

[0005] The purpose of the crankcase ventilation system is to extract and separate the air-fuel mixture inside the crankcase and allow it to re-enter combustion, thus forming a system circulation. The air-fuel mixture inside the crankcase mainly originates from piston leakage. When the amount of air re-entering combustion is less than the piston leakage and the amount of fresh air, it can easily lead to positive pressure (≤1 kPa) inside the crankcase, which will not meet the national standard requirement for negative pressure.

[0006] Under the aforementioned low-load conditions, the crankcase pressure is mainly regulated by the negative pressure source in the intake manifold and the flow capacity of the PCV valve. Under high-load conditions, the crankcase pressure is regulated by the negative pressure source after the air filter and before the booster. However, this method can only control the crankcase pressure within ≤+1kPa, which is still somewhat different from a complete negative pressure (≤0kPa), and therefore may result in emissions not meeting standards.

[0007] Therefore, there is an urgent need for crankcase negative pressure control systems, crankcase negative pressure control methods, and automobiles to address the technical problems existing in the current technology to a certain extent. Summary of the Invention

[0008] The purpose of this application is to provide a crankcase negative pressure control system, a crankcase negative pressure control method, and an automobile, which to a certain extent solves the technical problem of non-compliance with emission standards caused by positive pressure in the existing crankcase.

[0009] This application provides a crankcase negative pressure control system, including a low-load operating condition circuit and a high-load operating condition circuit;

[0010] The low-load operating condition circuit includes a first crankcase blow-by unit, a first separation blow-by unit, and an air compensation unit; one end of the first separation blow-by unit is connected to the first crankcase blow-by unit and the other end is connected to the engine through the intake manifold; one end of the air compensation unit is connected to the crankcase through a pipe passage and the other end is connected to the air filter.

[0011] The air compensation unit is equipped with a differential pressure controller, which can increase the resistance to air being introduced into the crankcase and reduce the air flow rate, so that the crankcase is in a negative pressure state under low load conditions.

[0012] The high-load operating circuit includes a first crankcase swivel unit, a second crankcase swivel unit, an auxiliary ventilation unit, the air compensation unit, and a supercharger unit connected to the engine; the two ends of the auxiliary ventilation unit are respectively connected to the first crankcase swivel unit and the supercharger unit; the two ends of the air compensation unit are respectively connected to the second crankcase swivel unit and the supercharger unit.

[0013] The auxiliary ventilation unit works in conjunction with the air compensation unit to keep the crankcase under negative pressure under high load conditions.

[0014] In the above technical solution, the differential pressure controller further includes a housing, a partition plate, and a baffle plate;

[0015] The partition plate is disposed on the housing and divides the housing into a compensation channel and a flow guiding channel;

[0016] The housing has an air inlet at one end near the air filter that communicates with the compensation channel; and an air outlet at one end away from the air filter that communicates with the flow guide channel.

[0017] The baffles are staggered in the compensation channel, so that the air in the compensation channel flows in a bent manner from the air inlet end to the air outlet end, thereby increasing the resistance to the air being introduced into the crankcase and reducing the air flow rate.

[0018] A first one-way umbrella valve is provided on the partition plate near the air inlet, and a second one-way umbrella valve is provided on the partition plate near the air outlet.

[0019] In the above technical solution, the first part of the baffle is disposed on the side wall of the housing at a first preset angle, the second part of the baffle is disposed on the partition plate at the first preset angle, and the first part of the baffle and the second part of the baffle are arranged alternately so that the air in the compensation channel flows in a bent manner from the air inlet end to the air outlet end.

[0020] Alternatively, the baffles in the first part are arranged in an alternating pattern at a first preset angle near the air inlet, and the baffles in the second part are arranged in an alternating pattern at a second preset angle near the air outlet.

[0021] In the above technical solution, the supercharging unit further includes a supercharger and an intake manifold;

[0022] One end of the turbocharger is connected to the intake manifold, and the other end is connected to the auxiliary ventilation unit and the air compensation unit respectively.

[0023] Under high load conditions, when the speed of the turbocharger is higher than the rated value, the auxiliary ventilation unit and the air compensation unit work simultaneously; when the speed of the turbocharger is lower than the rated value, the air compensation unit works alone.

[0024] In the above technical solution, the first crankcase extension unit further includes a crankcase, a cylinder head, and a low-load oil-gas separator;

[0025] The crankcase, the cylinder head, and the low-load oil-gas separator are connected in sequence.

[0026] In the above technical solution, the first separation post-connection unit further includes a PCV valve and a first separation pipeline;

[0027] The low-load oil-gas separator is connected to the intake manifold through the first separation pipeline;

[0028] The PCV valve is located at one end of the first separation pipeline near the low-load oil-gas separator.

[0029] In the above technical solution, the second crankcase chuck unit further includes a high-load oil-gas separator;

[0030] The two ends of the high-load oil-gas separator are respectively connected to the cylinder head and the air compensation unit.

[0031] In the above technical solution, the auxiliary ventilation unit further includes an auxiliary ventilation pipeline;

[0032] One end of the auxiliary ventilation pipeline is connected to the low-load oil-gas separator, and the other end is connected to the booster.

[0033] A one-way flow control valve is installed on the auxiliary ventilation pipeline.

[0034] This application also provides a crankcase negative pressure control method, based on the above-mentioned crankcase negative pressure control system, comprising the following steps:

[0035] Under low-load operating conditions, the crankcase has a second pressure, the low-load oil-gas separator has a fourth pressure higher than the second pressure, the intake manifold has a third pressure between the second pressure and the fourth pressure, and the air filter has a first pressure.

[0036] The intake manifold and the PCV valve can draw out fuel vapor and water vapor from the crankcase and introduce them into the engine through the intake manifold; the differential pressure controller adjusts the gas flow rate in the air compensation unit so that the second pressure is less than the first pressure, so that the crankcase is in a negative pressure state.

[0037] Under high-load operating conditions, the crankcase has the second pressure, the high-load oil-gas separator has a fifth pressure higher than the second pressure, the air filter has the first pressure, and the intake manifold has a third pressure between the second pressure and the fifth pressure.

[0038] When the speed of the turbocharger is less than the rated value, the fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, the air filter, the turbocharger, and the intake manifold;

[0039] When the turbocharger's speed is higher than the rated value, the fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, the air filter, the turbocharger, and the intake manifold; the low-load oil-gas separator draws out the fuel vapor and water vapor in the crankcase and sequentially introduces them into the engine through the one-way flow control valve, the air filter, the turbocharger, and the intake manifold.

[0040] This application also provides an automobile including the aforementioned crankcase negative pressure control system.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] This application provides a crankcase negative pressure control system, including a low-load operating condition circuit and a high-load operating condition circuit;

[0043] The low-load operating condition circuit includes a first crankcase blow-by unit, a first separation blow-by unit, and an air compensation unit; one end of the first separation blow-by unit is connected to the first crankcase blow-by unit and the other end is connected to the engine through the intake manifold; one end of the air compensation unit is connected to the crankcase through a pipe passage and the other end is connected to the air filter.

[0044] The air compensation unit is equipped with a differential pressure controller, which can increase the resistance to air being introduced into the crankcase and reduce the air flow rate, so that the crankcase is in a negative pressure state under low load conditions.

[0045] The high-load operating circuit includes a first crankcase swivel unit, a second crankcase swivel unit, an auxiliary ventilation unit, the air compensation unit, and a supercharger unit connected to the engine; the two ends of the auxiliary ventilation unit are respectively connected to the first crankcase swivel unit and the supercharger unit; the two ends of the air compensation unit are respectively connected to the second crankcase swivel unit and the supercharger unit.

[0046] The auxiliary ventilation unit works in conjunction with the air compensation unit to keep the crankcase under negative pressure under high load conditions.

[0047] In summary, a differential pressure controller is installed on the air compensation unit. Through the special structure of the differential pressure controller, the flow cross-sectional area of ​​the compensation channel is changed, which increases the resistance to air being introduced into the crankcase and thus reduces the air flow rate, so that the crankcase is in a negative pressure state under low load conditions, thereby ensuring that the crankcase is always in a negative pressure state under low load conditions.

[0048] In addition, when the turbocharger speed is higher than the rated value, the low-load oil-gas separator and the high-load oil-gas separator can work simultaneously, which can draw out a large amount of fuel vapor and water vapor in the crankcase, increase the circulating air volume, and thus keep the crankcase in a negative pressure state.

[0049] This application also provides a crankcase negative pressure control method, based on the above-mentioned crankcase negative pressure control system, comprising the following steps:

[0050] Under low-load operating conditions, the crankcase has a second pressure, the low-load oil-gas separator has a fourth pressure higher than the second pressure, the intake manifold has a third pressure between the second pressure and the fourth pressure, and the air filter has a first pressure.

[0051] The intake manifold and the PCV valve can draw out fuel vapor and water vapor from the crankcase and introduce them into the engine through the intake manifold; the differential pressure controller adjusts the gas flow rate in the air compensation unit so that the second pressure is less than the first pressure, so that the crankcase is in a negative pressure state.

[0052] Under high-load operating conditions, the crankcase has the second pressure, the high-load oil-gas separator has a fifth pressure higher than the second pressure, the air filter has the first pressure, and the intake manifold has a third pressure between the second pressure and the fifth pressure.

[0053] When the speed of the turbocharger is less than the rated value, the fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, the air filter, the turbocharger, and the intake manifold;

[0054] When the turbocharger's speed is higher than the rated value, the fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, the air filter, the turbocharger, and the intake manifold; the low-load oil-gas separator draws out the fuel vapor and water vapor in the crankcase and sequentially introduces them into the engine through the one-way flow control valve, the air filter, the turbocharger, and the intake manifold.

[0055] In summary, a differential pressure controller is installed on the air compensation unit. Through the special structure of the differential pressure controller, the flow cross-sectional area of ​​the compensation channel is changed, which increases the resistance to air being introduced into the crankcase and thus reduces the air flow rate, so that the crankcase is in a negative pressure state under low load conditions, thereby ensuring that the crankcase is always in a negative pressure state under low load conditions.

[0056] In addition, when the turbocharger speed is higher than the rated value, the low-load oil-gas separator and the high-load oil-gas separator can work simultaneously, which can draw out a large amount of fuel vapor and water vapor in the crankcase, increase the circulating air volume, and thus keep the crankcase in a negative pressure state.

[0057] This application also provides an automobile that includes the aforementioned crankcase negative pressure control system, and thus has all the beneficial effects of the aforementioned crankcase negative pressure control system, which will not be specifically described here. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0059] Figure 1 A structural block diagram of the crankcase negative pressure control system provided in this application under low load conditions;

[0060] Figure 2 A structural block diagram of the crankcase negative pressure control system provided in this application under high load conditions;

[0061] Figure 3 This is a schematic diagram of the differential pressure controller in the crankcase negative pressure control system provided in this application.

[0062] Reference numerals in the attached diagram: 3-First crankcase blow-by unit; 4-First separation blow-by unit; 5-Air compensation unit; 6-Pipe passage; 7-Differential pressure controller; 8-Crankcase; 9-Second crankcase blow-by unit; 10-Boost unit; 11-Intake manifold; 12-Housing housing; 13-Divider plate; 14-Baffle; 15-Compensation channel; 16-Guide channel; 17-Air filter; 18-Intake port; 19-Outtake port; 20-First one-way umbrella valve; 21-Second one-way umbrella valve; 22-Booster; 23-Auxiliary ventilation unit; 24-Cylinder head; 25-Low-load oil-gas separator; 26-PCV valve; 27-First separation pipeline; 28-High-load oil-gas separator; 29-Auxiliary ventilation pipeline; 30-One-way flow control valve. Detailed Implementation

[0063] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0064] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0065] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0066] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0067] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0068] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0069] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0070] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0071] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0072] Example 1

[0073] This application provides a crankcase negative pressure control system, including a low-load operating condition circuit and a high-load operating condition circuit. The low-load operating condition circuit corresponds to the engine's low-speed operation. When the engine is running at low speed, the amount of combustible mixture leaking during the compression stroke and combustion products leaking during the power stroke is relatively small and is introduced into the crankcase 8 through the piston rings and cylinders. The high-load operating condition circuit corresponds to the engine's high-speed operation. When the engine is running at high speed, the amount of combustible mixture leaking during the compression stroke and combustion products leaking during the power stroke is relatively large and is introduced into the crankcase 8 through the piston rings and cylinders.

[0074] Regardless of whether the engine is running at low or high speed, the combustible mixture and combustion products leaking into the crankcase 8 will cause the engine oil in the crankcase 8 to deteriorate. Therefore, it is necessary to decompose and reuse the combustible mixture and combustion products leaking into the crankcase 8. The following is a detailed explanation with reference to the attached drawings.

[0075] Combination Figure 1 As shown, the low-load operating circuit includes a first crankcase blow-by unit 3, a first separation blow-by unit 4, and an air compensation unit 5; wherein one end of the first separation blow-by unit 4 is connected to the first crankcase blow-by unit 3 and the other end is connected to the engine through the intake manifold 11.

[0076] Specifically, in combination Figure 1 As shown, the first crankcase blow-by unit 3 includes a crankcase 8, a cylinder head 24, and a low-load oil-gas separator 25; the crankcase 8, the cylinder head 24, and the low-load oil-gas separator 25 are connected in sequence; under normal circumstances, the low-load oil-gas separator 25 is located in the cylinder head 24.

[0077] Specifically, in combination Figure 1 As shown, the first separation post-separation unit 4 includes a PCV valve 26 and a first separation pipeline 27; the low-load oil-gas separator 25 is connected to the intake manifold 11 through the first separation pipeline 27; the PCV valve 26 is located at one end of the first separation pipeline 27 near the low-load oil-gas separator 25.

[0078] Furthermore, the crankcase 8 has a second pressure P2, the low-load oil-gas separator 25 has a fourth pressure P4, and the intake manifold 11 has a third pressure P3. In actual use, the third pressure P3 (negative pressure) in the intake manifold 11 and the PCV valve 26 (flow control element) draw gas out of the crankcase 8. The second pressure P2 in the crankcase 8 mainly originates from the leakage of the engine piston rings. Under low-load conditions, the third pressure P3 is relatively negative, and a pressure difference exists between the second pressure P2 and the third pressure P3, allowing air to flow through. The second pressure P2 will form a negative pressure under the action of the third pressure P3. To ensure a constant gas volume in the crankcase 8, an air compensation unit 5 is also installed under these conditions to compensate for the gas in the crankcase 8.

[0079] Specifically, one end of the air compensation unit 5 is connected to the crankcase 8 via a pipe passage 6, and the other end is connected to the air filter 17. This means that air is filtered by the air filter 17 and then guided into the crankcase 8, ensuring that the total gas volume in the crankcase 8 remains constant. When air flows into the crankcase 8, since the first air pressure P1 is atmospheric pressure, the second pressure P2 in the crankcase 8 will approach atmospheric pressure, which would not meet the negative pressure requirement for the crankcase 8 in the national standard. Based on this, this application provides a differential pressure controller 7 on the air compensation unit 5. The differential pressure controller 7 can increase the resistance to air being introduced into the crankcase 8 and reduce the air flow rate, so that the crankcase 8 is in a negative pressure state under low load conditions.

[0080] Furthermore, combined Figure 3 As shown, the differential pressure controller 7 includes a housing 12, a partition plate 13, and a baffle plate 14; wherein, the partition plate 13 is disposed on the housing 12, and the partition plate 13 extends along the extension direction of the housing 12 and divides the housing 12 into a compensation channel 15 and a guide channel 16; the end of the housing 12 near the air filter 17 has an air inlet 18 that communicates with the compensation channel 15; the end of the housing 12 away from the air filter 17 has an air outlet 19 that communicates with the guide channel 16; that is, the air inlet 18 is connected to the air filter 17, and the air outlet 19 is connected to the crankcase 8 through the pipe passage 6.

[0081] The compensation channel 15 is provided with staggered baffles 14, which causes the air in the compensation channel 15 to flow in a bent manner from the air inlet 18 end to the air outlet 19 end, so as to increase the resistance of the air being introduced into the crankcase 8 and reduce the air flow rate. A first one-way umbrella valve 20 is provided on the partition plate 13 near the air inlet 18, and a second one-way umbrella valve 21 is provided on the partition plate 13 near the air outlet 19.

[0082] In one preferred embodiment, taking six baffles 14 as an example, three baffles 14 are perpendicular to the inner wall of the housing 12, and these three baffles 14 are arranged at intervals and extend toward the partition plate 13; the remaining three baffles 14 are perpendicular to the partition plate 13, and these three baffles 14 are arranged at intervals and extend toward the inner wall of the housing 12; in addition, the three baffles 14 on the inner wall of the housing 12 and the three baffles 14 on the partition plate 13 are arranged alternately, so that the air in the compensation channel 15 flows in a bent (serpentine) manner from the air inlet 18 end to the air outlet 19 end;

[0083] Another preferred embodiment, still taking six baffles 14 as an example, three baffles 14 are inclined at a 30° angle to the inner wall of the housing 12 (the baffles 14 and the inner wall of the housing 12 are at a 30° angle), and the three baffles 14 are spaced apart and extend towards the partition plate 13; the remaining three baffles 14 are inclined at a 30° angle to the partition plate, and the three baffles 14 are spaced apart and extend towards the inner wall of the housing 12; in addition, the three baffles 14 on the inner wall of the housing 12 and the three baffles 14 on the partition plate 13 are staggered, so that the air in the compensation channel 15 flows in a zigzag (serpentine) manner from the air inlet 18 end to the air outlet 19 end;

[0084] In another preferred embodiment, taking a baffle 14 having 7 units as an example, combined with... Figure 3 As shown, four baffles 14 are disposed on the inner sidewall of the housing 12, and the remaining three baffles 14 are disposed on the partition plate 13. Of the four baffles on the inner sidewall of the housing 12, two baffles 14 are perpendicular to the inner sidewall of the housing 12, and the other two are disposed at a 30° angle to the inner sidewall of the housing 12; of the three baffles 14 on the partition plate 13, two baffles 14 are perpendicular to the partition plate 13, and the remaining two are disposed at a 30° angle to the partition plate 13; in addition, the four baffles on the inner sidewall of the housing 12 and the three baffles on the partition plate 13 are arranged alternately, so that the air in the compensation channel 15 flows in a zigzag (serpentine) manner from the air inlet 18 end to the air outlet 19 end.

[0085] In summary, a differential pressure controller 7 is provided on the air compensation unit 5. Through the special structure of the differential pressure controller 7, the flow cross-sectional area of ​​the compensation channel 15 is changed, which increases the resistance of air being introduced into the crankcase 8, thereby reducing the air flow rate, so that the crankcase 8 is in a negative pressure state under low load conditions, thus ensuring that the crankcase 8 is always in a negative pressure state under low load conditions.

[0086] Combination Figure 2 As shown, the high-load operating condition circuit includes a first crankcase blow-by unit 8, a second crankcase blow-by unit 9, an auxiliary ventilation unit 23, an air compensation unit 5, and a supercharger unit 10 connected to the engine; wherein, the two ends of the auxiliary ventilation unit 23 are respectively connected to the first crankcase blow-by unit 3 and the supercharger unit 10; the two ends of the air compensation unit 5 are respectively connected to the second crankcase blow-by unit 9 and the supercharger unit 10; the auxiliary ventilation unit 23 and the air compensation unit 5 work together to keep the crankcase 8 in a negative pressure state under high-load conditions.

[0087] Specifically, in combination Figure 2 As shown, the booster unit 10 includes a booster 22 and an intake manifold 11; one end of the booster 22 is connected to the intake manifold 11, and the other end is connected to the auxiliary ventilation unit 23 and the air compensation unit 5 respectively.

[0088] Furthermore, combined Figure 2 As shown, the second crankcase transmission unit 9 includes a high-load oil-gas separator 28; the two ends of the high-load oil-gas separator 28 are connected to the cylinder head 24 and the air compensation unit 5, respectively.

[0089] Furthermore, combined Figure 2 As shown, the auxiliary ventilation unit 23 includes an auxiliary ventilation pipeline 29; one end of the auxiliary ventilation pipeline 29 is connected to the low-load oil-gas separator 25, and the other end is connected to the booster 22; a one-way flow control valve 30 is provided on the auxiliary ventilation pipeline 29.

[0090] In actual use, under high load conditions, when the speed of the turbocharger 22 is less than the rated value (the rated value is 1600 rpm as an example), the air compensation unit 5 works alone. Specifically, the crankcase 8 has a second pressure P2, the high-load oil-gas separator 28 has a fifth pressure P5, the air filter 17 has a first pressure P1, and the intake manifold 11 has a third pressure P3. At this time, the gas flow path is: crankcase 8 → high-load oil-gas separator 28 → outlet 19 → guide channel 16 → intake port 18 → air filter → turbocharger 22 → intake manifold 11 → engine.

[0091] When the turbocharger 22 rotates at a speed higher than its rated value, i.e., above 1600 rpm, the auxiliary ventilation unit 23 and the air compensation unit 5 operate simultaneously. Specifically, the crankcase 8 has a second pressure P2, the high-load oil-gas separator 28 has a fifth pressure P5, the air filter 17 has a first pressure P1, and the intake manifold 11 has a third pressure P3. At this time, the gas flow path through the air compensation unit 5 is: crankcase 8 → high-load oil-gas separator 28 → outlet 19 → guide channel 16 → intake port 18 → air filter → turbocharger 22 → intake manifold 11 → engine. At this time, the gas flow path through the auxiliary ventilation unit 23 is: crankcase 8 → low-load oil-gas separator 25 → one-way flow control valve 30 → air filter → turbocharger 22 → intake manifold 11 → engine.

[0092] It is worth noting that the opening and closing of the one-way flow control valve 30 is determined by the pressure in the intake manifold 11: when the system booster 22 is engaged, the pressure in the intake manifold 11 increases, and the one-way flow control valve 30 closes; otherwise, it opens.

[0093] In summary, when the speed of the turbocharger 22 is higher than the rated value, the low-load oil-gas separator 25 and the high-load oil-gas separator 28 can work simultaneously, which can draw out a large amount of fuel vapor and water vapor in the crankcase 8, increase the circulating air volume, and thus keep the crankcase 8 in a negative pressure state.

[0094] Example 2

[0095] This application provides a crankcase negative pressure control method, based on the above-mentioned crankcase negative pressure control system, including the following steps:

[0096] Under low-load operating conditions, the crankcase has a second pressure P2, the low-load oil-gas separator has a fourth pressure P4 higher than the second pressure P2, the intake manifold has a third pressure P3 between the second pressure P2 and the fourth pressure P4, and the air filter has a first pressure P1. The intake manifold and PCV valve can draw out fuel vapor and water vapor from the crankcase and introduce them into the engine through the intake manifold. The differential pressure controller adjusts the gas flow rate in the air compensation unit so that the second pressure P2 is less than the first pressure P1, thus keeping the crankcase under negative pressure. In other words, a differential pressure controller is installed on the air compensation unit. Through the aforementioned special structure of this differential pressure controller, it is equivalent to changing the flow cross-sectional area of ​​the compensation channel, which increases the resistance to air entering the crankcase, thereby reducing the air flow rate, so that the crankcase is under negative pressure under low-load conditions, thus ensuring that the crankcase is always under negative pressure under low-load conditions.

[0097] Under high-load operating conditions, the crankcase has a second pressure P2, the high-load oil-gas separator has a fifth pressure P5 higher than the second pressure P2, the air filter has a first pressure P1, and the intake manifold has a third pressure P2 between the second pressure P2 and the fifth pressure P5. When the turbocharger speed is lower than the rated value, fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, air filter, turbocharger, and intake manifold.

[0098] When the turbocharger's speed exceeds its rated value, fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, air filter, turbocharger, and intake manifold. The low-load oil-gas separator draws out the fuel vapor and water vapor from the crankcase and sequentially introduces them into the engine through the one-way flow control valve, air filter, turbocharger, and intake manifold. In other words, when the turbocharger's speed exceeds its rated value, the low-load and high-load oil-gas separators can operate simultaneously, drawing out a large amount of fuel vapor and water vapor from the crankcase, increasing the circulating air volume, and thus keeping the crankcase under negative pressure at all times.

[0099] Example 3

[0100] This application also provides an automobile that includes the aforementioned crankcase negative pressure control system, and thus has all the beneficial effects of the aforementioned crankcase negative pressure control system, which will not be specifically described here.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A crankcase negative pressure control system, characterized in that, This includes circuits for low-load operation and circuits for high-load operation; The low-load operating condition circuit includes a first crankcase blow-by unit, a first separation blow-by unit, and an air compensation unit; one end of the first separation blow-by unit is connected to the first crankcase blow-by unit and the other end is connected to the engine through the intake manifold; one end of the air compensation unit is connected to the crankcase through a pipe passage and the other end is connected to the air filter. The air compensation unit is equipped with a differential pressure controller, which can increase the resistance to air being introduced into the crankcase and reduce the air flow rate, so that the crankcase is in a negative pressure state under low load conditions. The high-load operating circuit includes a first crankcase blow-by unit, a second crankcase blow-by unit, an auxiliary ventilation unit, the air compensation unit, and a supercharger unit connected to the engine; the two ends of the auxiliary ventilation unit are respectively connected to the first crankcase blow-by unit and the supercharger unit; the two ends of the air compensation unit are respectively connected to the second crankcase blow-by unit and the supercharger unit. The auxiliary ventilation unit works in conjunction with the air compensation unit to keep the crankcase under negative pressure under high load conditions. The differential pressure controller includes a housing, a partition plate, and a baffle plate; The partition plate is disposed on the housing and divides the housing into a compensation channel and a flow guiding channel; The housing has an air inlet at one end near the air filter that communicates with the compensation channel; and an air outlet at one end away from the air filter that communicates with the flow guide channel. The baffles are staggered in the compensation channel, so that the air in the compensation channel flows in a bent manner from the air inlet end to the air outlet end, thereby increasing the resistance to the air being introduced into the crankcase and reducing the air flow rate. A first one-way umbrella valve is provided on the partition plate near the air inlet, and a second one-way umbrella valve is provided on the partition plate near the air outlet. The first part of the baffle is set on the side wall of the housing at a first preset angle, and the second part of the baffle is set on the partition plate at the first preset angle. The first part of the baffle and the second part of the baffle are arranged alternately so that the air in the compensation channel flows in a bent manner from the air inlet end to the air outlet end. Alternatively, the baffles in the first part are arranged in an alternating pattern at a first preset angle near the air inlet, and the baffles in the second part are arranged in an alternating pattern at a second preset angle near the air outlet. The supercharging unit includes a supercharger and an intake manifold; One end of the turbocharger is connected to the intake manifold, and the other end is connected to the auxiliary ventilation unit and the air compensation unit respectively. Under high load conditions, when the speed of the turbocharger is higher than the rated value, the auxiliary ventilation unit and the air compensation unit work simultaneously; when the speed of the turbocharger is lower than the rated value, the air compensation unit works alone. The first crankcase blow-by unit includes a crankcase, a cylinder head, and a low-load oil-gas separator; The crankcase, the cylinder head, and the low-load oil-gas separator are connected in sequence. The first separation and subsequent connection unit includes a PCV valve and a first separation pipeline; The low-load oil-gas separator is connected to the intake manifold through the first separation pipeline; The PCV valve is located at one end of the first separation pipeline near the low-load oil-gas separator. The second crankcase chuck unit includes a high-load oil-gas separator; The two ends of the high-load oil-gas separator are respectively connected to the cylinder head and the air compensation unit; The auxiliary ventilation unit includes auxiliary ventilation piping; One end of the auxiliary ventilation pipeline is connected to the low-load oil-gas separator, and the other end is connected to the booster. A one-way flow control valve is installed on the auxiliary ventilation pipeline.

2. A crankcase negative pressure control method, based on the crankcase negative pressure control system described in claim 1, characterized in that, Includes the following steps: Under low-load operating conditions, the crankcase has a second pressure, the low-load oil-gas separator has a fourth pressure higher than the second pressure, the intake manifold has a third pressure between the second pressure and the fourth pressure, and the air filter has a first pressure. The intake manifold and the PCV valve can draw out fuel vapor and water vapor from the crankcase and introduce them into the engine through the intake manifold; the differential pressure controller adjusts the gas flow rate in the air compensation unit so that the second pressure is less than the first pressure, so that the crankcase is in a negative pressure state. Under high-load operating conditions, the crankcase has the second pressure, the high-load oil-gas separator has a fifth pressure higher than the second pressure, the air filter has the first pressure, and the intake manifold has a third pressure between the second pressure and the fifth pressure. When the speed of the turbocharger is less than the rated value, the fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, the air filter, the turbocharger, and the intake manifold; When the turbocharger's speed is higher than the rated value, the fuel vapor and water vapor in the crankcase are sequentially introduced into the engine through the high-load oil-gas separator, the air filter, the turbocharger, and the intake manifold; the low-load oil-gas separator draws out the fuel vapor and water vapor in the crankcase and sequentially introduces them into the engine through the one-way flow control valve, the air filter, the turbocharger, and the intake manifold.

3. A car, characterized in that, Includes the crankcase negative pressure control system as described in claim 1.

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