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

Abstract

The invention provides a crankcase negative pressure control system, a crankcase negative pressure control method and an automobile. The crankcase negative pressure control system comprises a low-load working condition loop and a high-load working condition loop. A pressure difference controller is arranged on the air compensation unit, and the pressure difference controller can increase the resistance of air guided into the crankcase, so that the crankcase is in a negative pressure state under the low-load working condition; the two ends of the auxiliary ventilation unit communicate with the first crankcase unit and the pressurization unit correspondingly. The two ends of the air compensation unit communicate with the second crankcase unit and the pressurization unit correspondingly. The auxiliary ventilation unit and the air compensation unit work cooperatively so that the crankcase can be in a negative pressure state under the high-load working condition. When the rotating speed of the supercharger is higher than the calibration value, the low-load oil-gas separator and the high-load oil-gas separator can work at the same time, a large amount of fuel steam and steam in the crankcase can be sucked out, the circulating gas amount is increased, and therefore the crankcase is in the negative pressure state all the time.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a crankcase negative pressure control system, a crankcase negative pressure control method and an automobile. Background Art

[0002] At present, the design of Qutong system is mainly divided into two routes: high-load working condition route and low-load working condition route.

[0003] Among them, the gas flow path in the low-load working condition is: the crankcase mixture passes through the crankcase → low-load oil-gas separator (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; the above process realizes the pressure balance and mixture replacement in the crankcase, reduces oil failure and increases oil service life.

[0004] Among them, the gas flow path in the high-load working condition is: the crankcase mixture passes through the crankcase → high-load oil-gas separator (high-load oil-gas separator is integrated in the cylinder head cover) → after the air filter → supercharger (supercharged model, naturally aspirated model has no) → intercooler → intake manifold → combustion in the combustion chamber; there is no fresh air replenishment under this working condition.

[0005] The purpose of the crankcase ventilation system is to extract and separate the mixture inside the crankcase and re-combust it, thus forming a system cycle. The mixture inside the crankcase mainly comes from the piston leakage. When the intake volume that re-combusts is less than the piston leakage and the fresh air volume, it is easy to cause a positive pressure in the crankcase (≤1kPa), which will not meet the national standard negative pressure requirements.

[0006] Under the above-mentioned 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 boost; however, this method can control the crankcase pressure within ≤+1kPa, which is still a certain distance from the complete negative pressure (≤0kPa), so it may cause emissions not to meet standards.

[0007] Therefore, there is an urgent need for a crankcase negative pressure control system, a crankcase negative pressure control method and an automobile, which can solve the technical problems existing in the prior art to a certain extent. Summary of the invention

[0008] The purpose of the present application is to provide a crankcase negative pressure control system, a crankcase negative pressure control method and a vehicle, which to a certain extent solve the technical problem of substandard emissions caused by the positive pressure in the existing crankcase.

[0009] The present 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 circuit includes a first crankcase blowby unit, a first separation blowby unit and an air compensation unit; one end of the first separation blowby unit is connected to the first crankcase blowby 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 provided with a pressure difference controller, which can increase the resistance of air introduced into the crankcase and reduce the flow rate of air introduction, so that the crankcase is in a negative pressure state under low load conditions;

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

[0013] The auxiliary ventilation unit cooperates with the air compensation unit to place the crankcase in a negative pressure state under high load conditions.

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

[0015] The partition plate is disposed on the shell and divides the shell into a compensation channel and a guide channel;

[0016] An end of the housing close to the air filter has an air inlet connected to the compensation channel; an end of the housing away from the air filter has an air outlet connected to the guide channel;

[0017] The baffles are staggered in the compensation channel, so that the air in the compensation channel flows in a curved manner from the air inlet end to the air outlet end, so as to increase the resistance of the air introduced into the crankcase and reduce the flow rate of the air introduced;

[0018] A first one-way umbrella valve is disposed at a position of the partition plate close to the air inlet, and a second one-way umbrella valve is disposed at a position of the partition plate close to the air outlet.

[0019] In the above technical solution, further, the baffles of the first part are arranged on the side wall of the shell at a first preset angle, the baffles of the second part are arranged on the partition plate at the first preset angle, and the baffles of the first part and the baffles of the second part 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 of the first part are arranged in a staggered manner at a first preset angle near the air inlet side, and the baffles of the second part are arranged in a staggered manner at a second preset angle near the air outlet side.

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

[0022] One end of the supercharger is in communication with the intake manifold, and the other end is in communication with the auxiliary ventilation unit and the air compensation unit respectively;

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

[0024] In the above technical solution, further, the first crankcase blowby unit 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, further, the first separation backflow unit includes a PCV valve and a first separation pipeline;

[0027] The low-load oil-gas separator is in communication with the intake manifold via the first separation pipeline;

[0028] The PCV valve is arranged at one end of the first separation line close to the low-load oil-gas separator.

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

[0030] Both ends of the high-load oil-gas separator are communicated with the cylinder head and the air compensation unit respectively.

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

[0032] One end of the auxiliary ventilation pipeline is in communication with the low-load oil-gas separator, and the other end is in communication with the supercharger;

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

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

[0035] When under low-load motion 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 absorb the fuel vapor and water vapor in the crankcase and introduce them into the engine through the intake manifold; the pressure difference 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 sports 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 supercharger is less than a calibrated 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 supercharger, and the intake manifold;

[0039] When the speed of the supercharger is higher than a calibrated 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 supercharger, and the intake manifold; the low-load oil-gas separator absorbs 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 supercharger, and the intake manifold.

[0040] The present application also provides an automobile, comprising the above-mentioned crankcase negative pressure control system.

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

[0042] The present 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 circuit includes a first crankcase blowby unit, a first separation blowby unit and an air compensation unit; one end of the first separation blowby unit is connected to the first crankcase blowby 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 provided with a pressure difference controller, which can increase the resistance of air introduced into the crankcase and reduce the flow rate of air introduction, so that the crankcase is in a negative pressure state under low load conditions;

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

[0046] The auxiliary ventilation unit cooperates with the air compensation unit to place the crankcase in a negative pressure state under high load conditions.

[0047] In summary, a pressure difference controller is provided on the air compensation unit. Through the above-mentioned special structure of the pressure difference controller, it is equivalent to changing the flow cross-sectional area of ​​the compensation channel, which increases the resistance of air introduced into the crankcase, thereby reducing the flow rate of air introduction, so that the crankcase under low load conditions is in a negative pressure state, thereby making the crankcase under low load conditions always in a negative pressure state.

[0048] In addition, when the speed of the supercharger is higher than the calibrated value, the low-load oil-gas separator and the high-load oil-gas separator can work at the same time, which can absorb a large amount of fuel vapor and water vapor in the crankcase, increase the circulating gas volume, and thus keep the crankcase in a negative pressure state at all times.

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

[0050] When under low-load motion 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 absorb the fuel vapor and water vapor in the crankcase and introduce them into the engine through the intake manifold; the pressure difference 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 sports 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 supercharger is less than a calibrated 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 supercharger, and the intake manifold;

[0054] When the speed of the supercharger is higher than a calibrated 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 supercharger, and the intake manifold; the low-load oil-gas separator absorbs 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 supercharger, and the intake manifold.

[0055] In summary, a pressure difference controller is provided on the air compensation unit. Through the above-mentioned special structure of the pressure difference controller, it is equivalent to changing the flow cross-sectional area of ​​the compensation channel, which increases the resistance of air introduced into the crankcase, thereby reducing the flow rate of air introduction, so that the crankcase under low load conditions is in a negative pressure state, thereby making the crankcase under low load conditions always in a negative pressure state.

[0056] In addition, when the speed of the supercharger is higher than the calibrated value, the low-load oil-gas separator and the high-load oil-gas separator can work at the same time, which can absorb a large amount of fuel vapor and water vapor in the crankcase, increase the circulating gas volume, and thus keep the crankcase in a negative pressure state at all times.

[0057] The present application also provides an automobile, including the above-mentioned crankcase negative pressure control system, and therefore has all the beneficial effects of the above-mentioned crankcase negative pressure control system, which will not be elaborated in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[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 structure of the pressure difference controller in the crankcase negative pressure control system provided in this application.

[0062] Figure markings: 3-first crankcase blowby unit; 4-first separation post-blowby unit; 5-air compensation unit; 6-pipe passage; 7-pressure difference controller; 8-crankcase; 9-second crankcase blowby unit; 10-boost unit; 11-intake manifold; 12-housing; 13-partition plate; 14-baffle; 15-compensation channel; 16-guide channel; 17-air filter; 18-inlet; 19-outlet; 20-first one-way umbrella valve; 21-second one-way umbrella valve; 22-supercharger; 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 DESCRIPTION

[0063] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve 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 interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

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

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

[0067] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0068] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the 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 relational terms used herein will be interpreted accordingly.

[0069] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0070] Variations in the shapes shown in the 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 drawings but include variations in shapes that occur during manufacturing.

[0071] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0072] Embodiment 1

[0073] The present 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 low-speed operation state of the engine. When the engine is running at a low speed, the amount of combustible mixture leaked in the compression stroke and the combustion products leaked in the power stroke introduced into the crankcase 8 through the piston ring and the cylinder is small. The high-load operating condition circuit corresponds to the high-speed operation state of the engine. When the engine is running at a high speed, the amount of combustible mixture leaked in the compression stroke and the combustion products leaked in the power stroke introduced into the crankcase 8 through the piston ring and the cylinder is large.

[0074] Regardless of whether the engine is running at a low speed or a 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, the combustible mixture and combustion products leaking into the crankcase 8 need to be decomposed and reused, which is explained in detail below with reference to the accompanying drawings.

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

[0076] Specifically, combined Figure 1 As shown, the first crankcase blowby 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; generally, the low-load oil-gas separator 25 is arranged on the cylinder head 24.

[0077] Specifically, combined Figure 1 As shown, the first separation backflow 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 arranged at one end of the first separation pipeline 27 close to 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 gas in the crankcase 8 is sucked out by the third pressure P3 (negative pressure) in the intake manifold 11 and the PCV valve 26 (flow control element). The second pressure P2 in the crankcase 8 mainly comes from the leakage of the engine piston ring. Under low-load conditions, the third pressure P3 has a large negative pressure. There is a pressure difference between the second pressure P2 and the third pressure P3, and the second pressure P2 will form a negative pressure under the action of the third pressure P3. In order to ensure that the amount of gas in the crankcase 8 remains unchanged, an air compensation unit 5 is also provided under this condition, and the air compensation unit 5 is used to compensate the gas in the crankcase 8.

[0079] Specifically, one end of the air compensation unit 5 is connected to the crankcase 8 through the pipe passage 6 and the other end is connected to the air filter 17, that is, the air is filtered by the air filter 17 and then directed to the crankcase 8 to ensure that the total amount of gas in the crankcase 8 remains unchanged. When the air is directed to the crankcase 8, since the first pressure P1 of the air is atmospheric pressure, the second pressure P2 in the crankcase 8 will be close to atmospheric pressure, which will not meet the negative pressure requirements of the crankcase 8 in the national standard. Based on this, the present application is provided with a pressure difference controller 7 on the air compensation unit 5, which can increase the resistance of the air introduced into the crankcase 8 and reduce the flow rate of the air introduced, so that the crankcase 8 is in a negative pressure state under low load conditions.

[0080] Furthermore, combined with Figure 3 As shown, the pressure difference controller 7 includes a shell 12, a partition plate 13 and a baffle 14; wherein the partition plate 13 is arranged on the shell 12, and the partition plate 13 extends along the extension direction of the shell 12 and divides the shell 12 into a compensation channel 15 and a guide channel 16; the end of the shell 12 close to the air filter 17 has an air inlet 18 connected to the compensation channel 15; the end of the shell 12 away from the air filter 17 has an air outlet 19 connected to 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] Among them, baffles 14 are staggered in the compensation channel 15, so that the air in the compensation channel 15 flows in a curved manner from the air inlet 18 end to the air outlet 19 end, so as to increase the resistance of air introduced into the crankcase 8 and reduce the flow rate of air introduction; a first one-way umbrella valve 20 is provided at the position of the partition plate 13 near the air inlet 18, and a second one-way umbrella valve 21 is provided at the position of the partition plate 13 near the air outlet 19.

[0082] In a preferred embodiment, taking the case where there are 6 baffles 14, 3 baffles 14 are perpendicular to the inner wall of the shell 12, and the 3 baffles 14 are arranged at intervals and extend toward the partition plate 13; the remaining 3 baffles 14 are perpendicular to the partition plate 13, and the 3 baffles 14 are arranged at intervals and extend toward the inner wall of the shell 12; in addition, the 3 baffles 14 on the inner wall of the shell 12 and the 3 baffles 14 on the partition plate 13 are arranged alternately, so that the air in the compensation channel 15 flows from the air inlet 18 end to the air outlet 19 end in a bent (snake-shaped) manner;

[0083] Another preferred embodiment still takes the example of six baffles 14, wherein three baffles 14 are arranged at an angle of 30° on the inner wall of the shell 12 (the angle between the baffle 14 and the inner wall of the shell 12 is 30°), and the three baffles 14 are arranged at intervals and extend toward the partition plate 13; the remaining three baffles 14 are arranged at an angle of 30° on the partition plate, and the three baffles 14 are arranged at intervals and extend toward the inner wall of the shell 12; in addition, the three baffles 14 on the inner wall of the shell 12 and the three baffles 14 on the partition plate 13 are arranged alternately, so that the air in the compensation channel 15 flows from the air inlet 18 end to the air outlet 19 end in a bent (snake-shaped) manner;

[0084] In another preferred embodiment, taking the baffle 14 having 7 as an example, combined with Figure 3 As shown, 4 baffles 14 are arranged on the inner side wall of the shell 12, and the remaining 3 baffles 14 are arranged on the partition plate 13. Among the 4 baffles 14 on the inner side wall of the shell 12, 2 baffles 14 are perpendicular to the inner side wall of the shell 12, and the other 2 are inclined at an angle of 30° to the inner side wall of the shell 12; among the 3 baffles 14 on the partition plate 13, 2 baffles 14 are perpendicular to the partition plate 13, and the remaining 2 are inclined at an angle of 30° to the partition plate 13; in addition, the 4 baffles 14 on the inner side wall of the shell 12 and the 3 baffles 14 on the partition plate 13 are arranged alternately, so that the air in the compensation channel 15 flows from the air inlet 18 end to the air outlet 19 end in a bent (snake-shaped) manner.

[0085] In summary, a pressure difference controller 7 is provided on the air compensation unit 5. Through the above-mentioned special structure of the pressure difference controller 7, it is equivalent to changing the flow cross-sectional area of ​​the compensation channel 15, which increases the resistance of air introduced into the crankcase 8, thereby reducing the flow rate of air introduction, so that the crankcase 8 under low load conditions is in a negative pressure state, thereby making the crankcase 8 under low load conditions always in a negative pressure state.

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

[0087] Specifically, combined Figure 2 As shown, the supercharging unit 10 includes a supercharger 22 and an intake manifold 11 ; one end of the supercharger 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 with Figure 2 As shown, the second crankcase blowby unit 9 includes a high-load oil-gas separator 28; both 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 with 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 supercharger 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 supercharger 22 is less than the calibrated value (the calibrated value is 1600 revolutions per minute 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→air outlet 19→guide channel 16→air inlet 18→air filter→supercharger 22→intake manifold 11→engine.

[0091] When the speed of the supercharger 22 is higher than the calibrated value, that is, higher than 1600 revolutions per minute, the auxiliary ventilation unit 23 and the air compensation unit 5 work simultaneously. Specifically, the crankcase 8 has the second pressure P2, the high-load oil-gas separator 28 has the fifth pressure P5, the air filter 17 has the first pressure P1, and the intake manifold 11 has the 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 → air outlet 19 → guide channel 16 → air inlet 18 → air filter → supercharger 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 → supercharger 22 → intake manifold 11 → engine.

[0092] It is worth noting that the on / off of the one-way flow control valve 30 needs to be determined by the pressure of the intake manifold 11: when the system supercharger 22 intervenes and the pressure in the intake manifold 11 increases, the one-way flow control valve 30 is closed, otherwise it is opened.

[0093] In summary, when the speed of the supercharger 22 is higher than the calibrated value, the low-load oil-gas separator 25 and the high-load oil-gas separator 28 can work simultaneously, and can absorb a large amount of fuel vapor and water vapor in the crankcase 8, thereby increasing the circulating gas volume, so that the crankcase 8 is always in a negative pressure state.

[0094] Embodiment 2

[0095] The present application provides a crankcase negative pressure control method, based on the above crankcase negative pressure control system, comprising the following steps:

[0096] When under low-load motion 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 the PCV valve can absorb the fuel vapor and water vapor in the crankcase and introduce them into the engine through the intake manifold; the pressure difference controller adjusts the gas flow rate in the air compensation unit so that the second pressure P2 is less than the first pressure P1, so that the crankcase is in a negative pressure state. That is, a pressure difference controller is provided on the air compensation unit, and the above-mentioned special structure of the pressure difference controller is equivalent to changing the flow cross-sectional area of ​​the compensation channel, which increases the resistance of air introduction to the crankcase, thereby reducing the flow rate of air introduction, so that the crankcase under low-load conditions is in a negative pressure state, so that the crankcase under low-load conditions is always in a negative pressure state.

[0097] Under high-load motion 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 speed of the supercharger is less than the calibrated value, the fuel vapor and water vapor in the crankcase are introduced into the engine through the high-load oil-gas separator, the air filter, the supercharger, and the intake manifold in sequence;

[0098] When the speed of the supercharger is higher than the calibration value, the fuel vapor and water vapor in the crankcase are introduced into the engine through the high-load oil-gas separator, air filter, supercharger, and intake manifold in sequence; the low-load oil-gas separator absorbs the fuel vapor and water vapor in the crankcase and introduces them into the engine through the one-way flow control valve, air filter, supercharger, and intake manifold in sequence. That is, when the speed of the supercharger is higher than the calibration value, the low-load oil-gas separator and the high-load oil-gas separator can work at the same time, and can absorb a large amount of fuel vapor and water vapor in the crankcase, increasing the circulating gas volume, so that the crankcase is always in a negative pressure state.

[0099] Embodiment 3

[0100] The present application also provides an automobile, including the above-mentioned crankcase negative pressure control system, and therefore has all the beneficial effects of the above-mentioned crankcase negative pressure control system, which will not be elaborated in detail here.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A crankcase negative pressure control system, characterized in that: Including low load condition circuit and high load condition circuit; The low-load operating circuit includes a first crankcase blowby unit, a first separation blowby unit and an air compensation unit; one end of the first separation blowby unit is connected to the first crankcase blowby 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 provided with a pressure difference controller, which can increase the resistance of air introduced into the crankcase and reduce the flow rate of air introduction, so that the crankcase is in a negative pressure state under low load conditions; The high-load operating circuit includes the first crankcase blowby unit, the second crankcase blowby unit, the auxiliary ventilation unit, the air compensation unit, and a supercharging unit connected to the engine; two ends of the auxiliary ventilation unit are respectively connected to the first crankcase blowby unit and the supercharging unit; two ends of the air compensation unit are respectively connected to the second crankcase blowby unit and the supercharging unit; The auxiliary ventilation unit cooperates with the air compensation unit to place the crankcase in a negative pressure state under high load conditions.

2. The crankcase negative pressure control system according to claim 1, characterized in that: The differential pressure controller comprises a shell, a partition plate and a baffle; The partition plate is disposed on the shell and divides the shell into a compensation channel and a guide channel; An end of the housing close to the air filter has an air inlet connected to the compensation channel; an end of the housing away from the air filter has an air outlet connected to the guide channel; The baffles are staggered in the compensation channel, so that the air in the compensation channel flows in a curved manner from the air inlet end to the air outlet end, so as to increase the resistance of the air introduced into the crankcase and reduce the flow rate of the air introduced; A first one-way umbrella valve is disposed at a position of the partition plate close to the air inlet, and a second one-way umbrella valve is disposed at a position of the partition plate close to the air outlet.

3. The crankcase negative pressure control system according to claim 2, characterized in that: The baffles of the first part are arranged on the side wall of the shell at a first preset angle, and the baffles of the second part are arranged on the partition plate at the first preset angle, and the baffles of the first part and the baffles of the second part 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 of the first part are arranged in a staggered manner at a first preset angle near the air inlet side, and the baffles of the second part are arranged in a staggered manner at a second preset angle near the air outlet side.

4. The crankcase negative pressure control system according to claim 3, characterized in that: The supercharging unit includes a supercharger and an intake manifold; One end of the supercharger is in communication with the intake manifold, and the other end is in communication with the auxiliary ventilation unit and the air compensation unit respectively; Under high load conditions, when the speed of the supercharger is higher than a calibrated value, the auxiliary ventilation unit and the air compensation unit work simultaneously; when the speed of the supercharger is lower than the calibrated value, the air compensation unit works alone.

5. The crankcase negative pressure control system according to claim 4, characterized in that: The first crankcase blowby 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.

6. The crankcase negative pressure control system according to claim 5, characterized in that: The first separation backflow unit includes a PCV valve and a first separation pipeline; The low-load oil-gas separator is in communication with the intake manifold via the first separation pipeline; The PCV valve is arranged at one end of the first separation line close to the low-load oil-gas separator.

7. The crankcase negative pressure control system according to claim 6, characterized in that: The second crankcase blowby unit includes a high-load oil-gas separator; Both ends of the high-load oil-gas separator are communicated with the cylinder head and the air compensation unit respectively.

8. The crankcase negative pressure control system according to claim 7, characterized in that: The auxiliary ventilation unit includes an auxiliary ventilation circuit; One end of the auxiliary ventilation pipeline is in communication with the low-load oil-gas separator, and the other end is in communication with the supercharger; A one-way flow control valve is arranged on the auxiliary ventilation pipeline.

9. A crankcase negative pressure control method, based on the crankcase negative pressure control system described in claim 8, characterized in that: The steps include: When under low-load motion 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 absorb the fuel vapor and water vapor in the crankcase and introduce them into the engine through the intake manifold; the pressure difference 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 sports 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 supercharger is less than a calibrated 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 supercharger, and the intake manifold; When the speed of the supercharger is higher than a calibrated 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 supercharger, and the intake manifold; the low-load oil-gas separator absorbs 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 supercharger, and the intake manifold.

10. An automobile, characterized in that: A crankcase negative pressure control system comprising any one of claims 1-8.

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