JP2013217262A - Blow-by gas treatment device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow-by gas treatment device of an internal combustion engine in order to introduce blow-by gas into an intake passage of the internal combustion engine loaded with a supercharger and treat the blow-by gas.SOLUTION: A blow-by gas treatment device is provided with: a first PCV passage 41 which is a passage communicating an ejector 50 installed in a circulation passage 45 circulating sucked air from a downstream to an upstream of a supercharger 24, with an inside of a crankcase 14, and opened and closed by a second PCV valve 42; and a second PCV passage 55 which is a passage communicating a downstream of a throttle valve 32 located the downstream of the supercharger 24, with the inside of the crankcase 14, and a flow passage area of which is adjusted by a first PCV valve 56. Furthermore, the blow-by gas treatment device closes the second PCV valve 42 prior to engine stop, and opens the first PCV valve 56, and performs engine stop pretreatment of closing the throttle valve 32.

Description

  The present invention relates to a blow-by gas processing apparatus for an internal combustion engine for introducing and processing blow-by gas into an intake passage of the internal combustion engine equipped with a supercharger.

  As an apparatus mounted on an internal combustion engine, a blow-by gas processing apparatus that introduces and processes gas leaked into a crankcase from a gap between an inner wall of a cylinder and a piston ring, that is, blow-by gas, is known. According to such a blow-by gas processing device, the blow-by gas stays in the crankcase by introducing the blow-by gas into the intake passage using the negative pressure generated in the intake passage and burning it in the combustion chamber. Corrosion and oil deterioration of the crankcase can be suppressed.

  Here, in an internal combustion engine equipped with a supercharger, since the degree of negative pressure generated in the intake passage is low, the processing capacity of such blow-by gas tends to decrease. Therefore, for example, in the one described in Patent Document 1, an ejector is provided in a circulation passage that circulates from the downstream to the upstream of the supercharger (strictly, the compressor), and the ejector is provided from the crankcase through the PCV passage. The blow-by gas introduced into is introduced into the intake passage through the circulation passage. The ejector forcibly causes intake air to flow through the circulation passage by utilizing the difference in pressure inside the intake passage between the upstream and downstream when the turbocharger is supercharged. This is a kind of jet pump that sucks blow-by gas into the ejector. By using such an ejector, the blow-by gas of the crankcase can be introduced into the intake passage even under a situation where the negative pressure in the intake passage is reduced due to the supercharging action of the supercharger. .

JP2011-236825A JP 2003-214131 A

  By the way, when the outside air temperature is extremely low, since low-temperature intake air flows through the circulation passage and the ejector, moisture contained in the blow-by gas may freeze in the circulation passage and the ejector. If such freezing occurs, the flow path through which the blow-by gas passes in the circulation passage and the ejector may be narrowed or blocked, and the blow-by gas may not be properly processed. Furthermore, when ice generated by such freezing when the supercharger is supercharged flows into the intake passage from the circulation passage or ejector, the ice that has flowed in collides with the compressor impeller of the supercharger, thereby causing the operation of the supercharger. There is also a risk of failure.

  Therefore, for example, in Patent Document 2, a heat transfer member such as a metal bracket is provided on a PCV pipe partially made of metal, and the heat transfer member is brought into contact with the cylinder head. . Thereby, the heat generated in the internal combustion engine with the operation of the internal combustion engine can be transmitted to the PCV piping to suppress freezing of moisture in the PCV piping. If the heat transfer member described in Patent Document 2 is provided in the circulation passage or the ejector, freezing in the circulation passage or the ejector can be suppressed during engine operation. However, even if the heat transfer member is employed in this way, sufficient heat from the internal combustion engine cannot be obtained while the engine is stopped, so that problems such as freezing of the circulation passage and ejector can still occur.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to circulate intake air to an ejector provided in a circulation passage by a differential pressure upstream and downstream of a supercharger and use the suction action of the ejector. In the blow-by gas processing apparatus for an internal combustion engine in which blow-by gas is introduced into the intake passage for processing, the circulation passage and ejector are prevented from freezing when the engine is stopped.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, there is provided a circulation passage for circulating the intake air from the downstream side to the upstream side of the supercharger in the intake passage, an ejector provided in the circulation passage, and an ejector that communicates with the inside of the crankcase. 1, a PCV passage, an outside air introduction passage through which the upstream of the supercharger in the intake passage and the crankcase communicate with each other, and a throttle located downstream of the supercharger In a blow-by gas processing apparatus for an internal combustion engine, comprising: a second PCV passage that communicates the downstream of the valve and the inside of the crankcase; and a first PCV valve that adjusts a flow area of the second PCV passage. A second PCV valve for opening and closing the first PCV passage is provided, the second PCV valve is closed before the engine is stopped, and the first PCV valve is closed. The Bed is an open state, and the gist thereof to perform the engine stop pretreatment to closed the throttle valve.

  Immediately before the engine is stopped, the engine speed is reduced as compared with normal engine operation, so the supercharging effect obtained by the supercharger is reduced. For this reason, if blow-by gas is introduced into the ejector from the crankcase by the blow-by gas processing device immediately before the engine is stopped, the blow-by gas introduced into the ejector is not introduced into the combustion chamber, and the turbocharger is introduced into the intake passage. It may stay in the vicinity, circulation path, or ejector. And the problem that the water | moisture content of the blowby gas which stayed in this way freezes, and the problem that the ice produced by freezing collides with the compressor impeller of a supercharger will arise.

  Therefore, in the above configuration, the blow-by gas is not introduced from the crankcase to the ejector through the first PCV passage by closing the second PCV valve before the engine stops. Yes. As a result, it is possible to scavenge the blow-by gas remaining in the circulation passage or the ejector by the air flowing through the circulation passage while restricting the introduction of a new blow-by gas into the circulation passage or the ejector. Therefore, according to the above configuration, freezing of the moisture of the blow-by gas after the engine stop as described above can be suppressed, and malfunction of the supercharger due to this can also be suppressed.

  Here, when the second PCV valve is closed as described above and blow-by gas is not introduced into the ejector, the amount of blow-by gas in the crankcase exceeds the allowable amount of the crankcase, and the excess There is a possibility that the blow-by gas will flow back through the outside air introduction passage.

  Therefore, in the above configuration, the blow-by gas is introduced from the inside of the crankcase to the intake passage through the second PCV passage by opening the first PCV valve before the engine stops. ing. As a result, the blow-by gas is prevented from flowing back into the outside air introduction passage while coping with freezing in the circulation passage and the ejector such as closing the second PCV valve immediately before the engine is stopped. be able to.

  Further, in the above configuration, the throttle valve is closed before the engine stops. As a result, the internal pressure of the intake passage on the upstream side of the throttle valve increases, so the amount of intake air supplied from the intake passage to the ejector increases, and the amount of blow-by gas introduced from the ejector to the intake passage increases by that amount. Will increase. Therefore, according to the above configuration, the blow-by gas retained in the circulation passage or the ejector can be introduced into the intake passage at an earlier stage. On the other hand, when the throttle valve is closed, the negative pressure generated downstream of the throttle valve increases, and the flow rate of blow-by gas introduced into the intake passage through the second PCV passage increases. Such a backflow of blow-by gas in the outside air introduction passage can be suitably suppressed.

  According to a second aspect of the present invention, in the blow-by gas processing apparatus for an internal combustion engine according to the first aspect, an exhaust bypass passage communicating the upstream and downstream of the supercharger in the exhaust passage, and opening and closing the exhaust bypass passage The exhaust gas bypass valve is further provided, and the exhaust bypass valve is closed when the engine stop pre-processing is performed before the engine is stopped.

  When the exhaust bypass valve in the exhaust bypass passage is opened, the exhaust flows around the supercharger, and the amount of exhaust supplied to the supercharger is reduced by the amount of the bypass. Therefore, the supercharging effect obtained by the supercharger is reduced.

  Therefore, according to the above configuration, before the engine stops, the exhaust bypass valve is closed in conjunction with the execution of the engine stop pretreatment, thereby reducing the amount of exhaust to be supercharged by the supercharger. Can do more. Therefore, the scavenging of the blow-by gas staying in the circulation passage or the ejector can be performed more quickly.

  According to a third aspect of the present invention, there is provided the blow-by gas processing apparatus for an internal combustion engine according to the first or second aspect, wherein an intake bypass passage communicating the upstream and downstream of the supercharger in the intake passage, and the intake bypass passage And an intake bypass valve that opens and closes the engine. The gist of the present invention is to close the intake bypass valve together with the execution of the engine stop pre-processing before the engine is stopped.

  When the intake bypass valve of the intake bypass passage is opened, the amount of intake air flowing through the circulation passage is reduced by the amount that flows into the intake bypass passage, and the suction effect of the blow-by gas obtained by the ejector is also reduced.

  Therefore, according to the above configuration, before the engine stops, the intake bypass valve is closed in conjunction with the execution of the engine stop process, thereby increasing the amount of intake air flowing through the circulation passage. Can do. Therefore, the scavenging of the blow-by gas staying in the circulation passage or the ejector can be performed more quickly.

  The “open valve” in the configuration described in claim 1 includes not only the fully opened state but also a substantially fully opened state in which the opening is slightly smaller than the fully opened state. In addition, the “valve closing” in the configuration described in claims 1 to 3 includes not only the fully closed state but also a substantially fully closed state in which the opening degree is slightly larger than the fully closed state.

The block diagram which shows schematic structure of one Embodiment which actualized this invention. The flowchart which shows the engine stop pre-processing of this embodiment. Sectional drawing which shows the flow of blow-by gas, intake air, and exhaust gas when the engine stop pretreatment of this embodiment is performed.

Hereinafter, an embodiment embodying a blow-by gas processing apparatus according to the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, a cylinder head 12 is attached to an upper portion of a cylinder block 11 of the internal combustion engine 10, and a head cover 13 is attached to the upper portion of the cylinder head 12. A crankcase 14 is formed at the lower part of the cylinder block 11, and an oil pan 15 is attached to the lower part of the crankcase 14. The oil pan 15 stores oil for engine lubrication. A piston 17 is accommodated in a cylinder 16 formed inside the cylinder block 11 so as to be able to reciprocate.

  In the intake passage 21 of the internal combustion engine 10, in order from the upstream in the intake flow direction (hereinafter simply referred to as “upstream”), an air cleaner 30 that filters intake air, an exhaust-driven supercharger 24 (strictly a compressor 25), and intake air An intercooler 31, a throttle valve 32, and a surge tank 34 are provided for cooling through heat exchange with the outside air. The opening degree of the throttle valve 32 is adjusted by a throttle motor 33. Then, through the control of the throttle valve 32, the flow passage area of the intake passage 21 of the internal combustion engine 10 is adjusted, and the amount of air taken into each cylinder of the internal combustion engine 10 through the intake passage 21 is adjusted.

  The supercharger 24 includes a compressor 25 provided in the intake passage 21 and a turbine 28 provided in the exhaust passage 22. The compressor 25 includes a compressor impeller 26 inside, and the turbine 28 includes a turbine wheel 29 inside. The compressor impeller 26 and the turbine wheel 29 are coupled via a shaft 27 so as to be integrally rotatable. In such a supercharger 24, when exhaust is blown onto the turbine wheel 29, the turbine wheel 29 and the compressor impeller 26 rotate together, whereby the intake air flowing through the intake passage 21 is pumped and forced into the combustion chamber of the internal combustion engine 10. Will be sent. That is, the intake air is supercharged.

  Fuel injected from a fuel injection valve (not shown) is supplied to each combustion chamber of each cylinder of the internal combustion engine 10. In addition, a communication passage 23 is formed inside the internal combustion engine 10 so as to communicate the inside of the head cover 13 and the crankcase 14. Further, in the internal combustion engine 10, unburned gas or combustion gas leaked from the combustion chamber into the crankcase 14 through the clearance between the inner wall of the cylinder 16 and the piston 17, that is, blow-by gas, is introduced into the intake air. A blow-by gas processing device is provided for burning and processing.

  The blow-by gas processing device communicates with the crankcase 14 and circulates the first PCV passage 41 into which blow-by gas is introduced from the inside of the crankcase 14 and the intake passage 21 for circulating the intake air from the downstream side to the upstream side of the compressor 25. A passage 45 (46, 47) and an ejector 50 provided in the circulation passage 45 are provided.

  One end of the first PCV passage 41 is connected to the head cover 13. An oil separator 40 for separating blowby gas and oil mist is disposed inside the head cover 13, and the first PCV passage 41 is connected to the head cover 13 via the oil separator 40. Further, the first PCV passage 41 is provided with a second PCV valve 42 that opens and closes the first PCV passage 41. In the present embodiment, the second PCV valve 42 is disposed on the upstream side of the first PCV passage 41 and at a position close to the oil separator 40.

  The circulation passage 45 includes an inflow passage 46 that connects the ejector 50 and the upstream of the intercooler 31 in the intake passage 21, and a discharge passage 47 that connects the ejector 50 and the upstream of the compressor 25 in the intake passage 21. These passages 46 and 47 connect the downstream and upstream of the compressor 25 in the intake passage 21 via an ejector 50. The ejector 50 is a kind of jet pump, and an inflow passage 46 and a discharge passage 47 are opened therein.

  When the supercharger 24 is supercharged, the inside of the intake passage 21 downstream of the supercharger 24 becomes high pressure, and a pressure difference is generated in the intake passage 21 between the upstream and downstream of the supercharger 24. Become. When the intake air in the intake passage 21 is introduced into the inflow passage 46 during such supercharging, the intake air is introduced into the ejector 50 from the inflow passage 46. The intake air thus introduced into the ejector 50 flows into the discharge passage 47 and is then introduced into the intake passage 21 upstream of the supercharger 24. When the intake air flows through the passages 46 and 47 through the ejector 50 in this way, a negative pressure is generated in the internal space of the ejector 50 at that time. The blow-by gas is sucked into the ejector 50 from the first PCV passage 41 by the negative pressure generated, and is further discharged from the ejector 50 into the discharge passage 47 together with the intake air. As described above, by using the ejector 50, the blow-by gas in the crankcase 14 is supplied to the intake passage 21 even under a situation where the negative pressure in the intake passage 21 is reduced due to the supercharging action of the supercharger 24. Can be introduced. Incidentally, the amount of blow-by gas introduced into the ejector 50 from the first PCV passage 41 increases as the amount of intake air flowing into the discharge passage 47 from the inflow passage 46 increases. For example, when the supercharging pressure is high and the differential pressure between the internal pressure upstream and the downstream internal pressure of the supercharger 24 is large in the intake passage 21, the pressure increases.

  Further, the blow-by gas processing device connects the upstream of the compressor 25 and the head cover 13 in the intake passage 21 and introduces the outside air into the crankcase 14, the downstream of the throttle valve 32, and the crankcase 14. And a second PCV passage 55 communicating with the inside. The outside air introduction passage 52 communicates with the inside of the crankcase 14 through the inside of the head cover 13 and the communication passage 23, and introduces outside air into the inside of the crankcase 14. The second PCV passage 55 has one end connected to the head cover 13 via the oil separator 40 and the other end connected to the surge tank 34 in the same manner as the first PCV passage 41. Further, a first PCV valve 56 is provided at one end of the second PCV passage 55, and the blow-by flowing through the second PCV passage 55 is adjusted by adjusting the opening degree of the first PCV valve 56. Gas is metered.

  The intake passage 21 is provided with an intake bypass passage 35 that communicates the upstream and downstream of the supercharger 24 (strictly, the compressor 25). The intake bypass passage 35 is opened and closed. An air bypass valve 36 corresponding to the intake bypass valve is provided. Here, there is a situation where the pressure of the intake air in the intake passage 21 suddenly increases, such as when the throttle valve 32 is suddenly closed. Under such circumstances, the intake air compressed by the compressor 25 is returned to the intake passage 21 upstream of the compressor 25 through the intake bypass passage 35 by opening the air bypass valve 36. .

  The exhaust passage 22 is provided with an exhaust bypass passage 37 that communicates the upstream and downstream of the supercharger 24 (strictly, the turbine 28), and the exhaust bypass passage 37 is opened and closed. A wastegate valve 38 corresponding to the exhaust bypass valve is provided. When the opening degree of the waste gate valve 38 is controlled, the flow rate of the exhaust gas passing through the exhaust bypass passage 37 is changed, so that the amount of exhaust gas flowing into the turbine wheel 29 is changed, and the rotational speed of the supercharger 24 is changed. Will be adjusted. The supercharging pressure of the internal combustion engine 10 is changed by adjusting the rotational speed of the supercharger 24.

  Various controls of the internal combustion engine 10 including such a blow-by gas processing device are executed by the control unit 60. The control unit 60 inputs / outputs signals to / from a CPU that executes various arithmetic processes, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores CPU calculation results, and the like. It has input / output ports and so on.

  Various sensors and switches including the following are connected to the input port of the control unit 60. That is, an ignition switch 64 for starting and stopping the internal combustion engine 10, a vehicle speed sensor 65 for detecting the vehicle speed, and a shift position sensor 67 for outputting a signal corresponding to the position of the shift lever 66 operated by the driver are connected. Yes.

  And the control part 60 grasps | ascertains an engine operation state based on the detection signal input from the said various sensors and switches, According to the grasped engine operation state, adjustment control of intake air amount, fuel injection amount, etc. Operation control of the internal combustion engine 10 is executed.

  By the way, when the outside air temperature is extremely low, low-temperature intake air flows through the circulation passage 45 and the ejector 50, so that the water contained in the blow-by gas is frozen, and as described above, the circulation passage 45 and the ejector. At 50, the flow path through which the blow-by gas passes may be narrowed or blocked, causing a problem that the blow-by gas is not properly processed. Further, when the ice generated by the freezing flows into the intake passage 21 from the circulation passage 45 or the ejector 50, the inflowed ice collides with the compressor impeller 26 of the supercharger 24. There is also a possibility that a problem such as malfunction occurs.

  Therefore, in the present embodiment, the engine stop pre-processing is executed in which the control unit 60 controls the second PCV valve 42, the first PCV valve 56, the throttle valve 32, the air bypass valve 36, and the waste gate valve 38. I have to. Hereinafter, the processing procedure of the engine stop pre-processing will be described with reference to FIG. The series of processes shown in FIG. 2 is repeatedly executed by the control unit 60 at predetermined intervals during engine operation.

  As shown in FIG. 2, in this series of processing, it is first determined whether or not it is immediately before the internal combustion engine 10 stops (step S110). Here, as to whether or not it is immediately before the internal combustion engine 10 stops, either of the following “condition A” is satisfied, or “condition B” and “condition C” are both satisfied. Is satisfied, the internal combustion engine 10 is determined to be immediately before stopping.

"Condition A": It is determined that the driver has performed the ignition off operation based on the detection signal input from the ignition switch 64.
“Condition B”: The vehicle speed detected by the vehicle speed sensor 65 is “0”.

“Condition C”: Based on the detection signal input from the shift position sensor 67, it is determined that the position of the shift lever 66 is in the parking position.
When it is determined that the internal combustion engine 10 is immediately before stopping (step S110: YES), depending on the amount of blow-by gas remaining in the circulation passage 45 or the ejector 50 when the internal combustion engine 10 stops as it is, as described above. May cause freezing. Therefore, before the internal combustion engine 10 is stopped, the second PCV valve 42 is fully closed, the first PCV valve 56 is fully opened, and the throttle valve 32 is fully closed (step S120). ). By performing the process of step S120, the blow-by gas is not introduced into the first PCV passage 41, while the blow-by gas is introduced into the second PCV passage 55.

  Subsequently, both the air bypass valve 36 and the waste gate valve 38 are fully closed (step S130). By performing the process of step S130, intake air does not pass through the intake bypass passage 35, and exhaust does not pass through the exhaust bypass passage 37. Thus, by performing the processing of step S120 and step S130, the flow mode of the blow-by gas, the intake air, and the exhaust gas in each passage is controlled, and this processing ends.

On the other hand, if it is determined that it is not immediately before the internal combustion engine 10 stops, the present process is terminated.
Next, the operation of this embodiment will be described with reference to FIG.

  Prior to the internal combustion engine 10 being stopped (step S110: YES in FIG. 2), the second PCV valve 42 is fully closed and the first PCV valve 56 is fully opened by the engine stop pretreatment, and The throttle valve 32 is fully closed (step S120).

  In this way, the second PCV valve 42 is fully closed, so that blow-by gas is not introduced from the crankcase 14 to the ejector 50 via the first PCV passage 41. As a result, the blow-by gas staying in the circulation passage 45 and the ejector 50 can be scavenged while restricting the introduction of a new blow-by gas into the circulation passage 45 and the ejector 50.

  Further, when the second PCV valve 42 is fully closed as described above and blow-by gas is not introduced into the ejector 50, the amount of blow-by gas in the crank case 14 exceeds the allowable amount of the crank case 14, The excess blow-by gas may flow back through the outside air introduction passage 52.

  Therefore, before the internal combustion engine 10 is stopped, the first PCV valve 56 is fully opened. As a result, the blow-by gas can be directly introduced from the crankcase 14 to the intake passage 21 without going through the circulation passage 45 or the ejector 50 immediately before the internal combustion engine 10 stops.

  Before the engine stops, the throttle valve 32 is fully closed. By performing the process of bringing the throttle valve 32 into the fully closed state together with the process of bringing the second PCV valve 42 into the fully closed state, the following action can be obtained. That is, when the throttle valve 32 is fully closed, the internal pressure of the intake passage 21 on the upstream side of the throttle valve 32 increases. For this reason, the amount of intake air supplied from the intake passage 21 to the ejector 50 increases, and the amount of blow-by gas introduced from the ejector 50 into the intake passage 21 increases by the increased amount. Further, by performing the process of fully closing the throttle valve 32 together with the process of fully opening the first PCV valve 56, the following action can be obtained. That is, when the throttle valve 32 is fully closed, the negative pressure generated downstream of the throttle valve 32 increases, and the flow rate of blow-by gas introduced into the intake passage 21 through the second PCV passage 55 increases. Become.

Further, together with the execution of the process of step S120 in FIG. 2, the air bypass valve 36 and the wastegate valve 38 are fully closed (step S130).
Here, if the waste gate valve 38 is fully opened, the exhaust gas flows through the turbine 28 by passing through the exhaust gas bypass passage 37. Since the amount of exhaust gas used for supercharging of the supercharger 24 is reduced by the amount detoured in this way, the supercharging effect obtained by the supercharger 24 is reduced.

  Therefore, before the internal combustion engine 10 is stopped, the waist PC is combined with the process of setting the second PCV valve 42 in the fully closed state and the process of setting the throttle valve 32 in the fully closed state. The gate valve 38 is fully closed. Thereby, since the amount of exhaust gas used for supercharging of the supercharger 24 can be increased, the blow-by gas staying in the circulation passage 45 and the ejector 50 can be scavenged more quickly.

  In addition, if the air bypass valve 36 is fully opened, intake air flows into the intake bypass passage 35. Thus, since the amount of intake air flowing through the circulation passage 45 is reduced by the amount that flows into the intake bypass passage 35, the suction effect of the blow-by gas obtained by the ejector 50 is reduced.

  Therefore, before the internal combustion engine 10 is stopped, the process of making the second PCV valve 42 fully closed and the process of making the throttle valve 32 fully closed are performed. The bypass valve 36 is fully closed. Thereby, since the amount of intake air flowing through the circulation passage 45 can be increased, the blow-by gas staying in the circulation passage 45 and the ejector 50 can be scavenged more quickly.

  If the second PCV valve 42 is arranged in the middle of the first PCV passage 41, the first PCV passage 41 has a passage upstream of the second PCV valve 42 to some extent. Become. When the engine stop pretreatment is executed, the second PCV valve 42 is fully closed, so that the blow-by gas stays in the first PCV passage 41 upstream of the second PCV valve 42. There is a fear. In consideration of these points, in the present embodiment, the second PCV valve 42 is disposed on the upstream side of the first PCV passage 41 and at a position close to the oil separator 40. Thereby, it is possible to prevent the blow-by gas from staying in the first PCV passage 41 with the execution of the engine stop pretreatment.

According to the embodiment described above, the following effects can be obtained.
(1) Blow-by gas is introduced from the crankcase 14 to the ejector 50 through the first PCV passage 41 by fully closing the second PCV valve 42 before the internal combustion engine 10 stops. I try not to. As a result, the blow-by gas staying in the circulation passage 45 or the ejector 50 can be scavenged by the air flowing through the circulation passage 45 while restricting the introduction of a new blow-by gas into the circulation passage 45 or the ejector 50. Therefore, freezing of moisture in the blow-by gas after the engine is stopped can be suppressed, and malfunctions of the supercharger 24 caused by this can also be suppressed.

  Further, before the internal combustion engine 10 is stopped, the first PCV valve 56 is fully opened to introduce blow-by gas from the crankcase 14 to the intake passage 21 through the second PCV passage 55. I am doing so. As a result, immediately before the internal combustion engine 10 stops, the blow-by gas enters the outside air introduction passage 52 while taking measures against freezing in the circulation passage 45 and the ejector 50 such that the second PCV valve 42 is fully closed. Backflow can be suppressed.

  Before the internal combustion engine 10 stops, the throttle valve 32 is closed. As a result, the internal pressure of the intake passage 21 on the upstream side of the throttle valve 32 increases, so the amount of intake air supplied from the intake passage 21 to the ejector 50 increases, and the increased amount from the ejector 50 to the intake passage 21 is increased. This will increase the amount of blow-by gas introduced. Therefore, the blowby gas staying in the circulation passage 45 and the ejector 50 can be introduced into the intake passage 21 at an earlier stage. On the other hand, when the throttle valve 32 is fully closed, the negative pressure generated downstream of the throttle valve 32 increases, and the flow rate of blow-by gas introduced into the intake passage 21 through the second PCV passage 55 increases. Therefore, the reverse flow of blow-by gas in the outside air introduction passage 52 as described above can be suitably suppressed.

  (2) Prior to the stop of the internal combustion engine 10, the waste gate valve 38 is fully closed together with the execution of the processing related to the second PCV valve 42, the first PCV valve 56, and the throttle valve 32. By doing so, the amount of exhaust gas used for supercharging of the supercharger 24 can be increased. Therefore, the scavenging of the blow-by gas accumulated in the circulation passage 45 and the ejector 50 can be performed more rapidly.

  (3) Prior to the internal combustion engine 10 being stopped, the air bypass valve 36 is fully closed together with the execution of the processing relating to the second PCV valve 42, the first PCV valve 56, and the throttle valve 32. By doing so, the amount of intake air flowing through the circulation passage 45 can be increased. Therefore, the scavenging of the blow-by gas accumulated in the circulation passage 45 and the ejector 50 can be performed more rapidly.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
Although the outside air introduction passage 52 is connected to the head cover 13, the connection portion of the outside air introduction passage 52 is not limited to this, and is connected so that the upstream of the supercharger 24 in the intake passage 21 communicates with the crankcase 14. For example, it may be configured to be connected to the crankcase 14.

  The intake bypass passage 35 and the circulation passage 45 are provided so as to be connected upstream of the intercooler 31 in the intake passage 21. The connection location of the intake bypass passage 35 and the circulation passage 45 is not limited to this. For example, the intake bypass passage 35 and the circulation passage 45 may be connected downstream of the intercooler 31 and connected to the upstream of the throttle valve 32. Such a connection mode may be adopted in either one of the intake bypass passage 35 and the circulation passage 45 or both.

  In the upstream of the supercharger 24, the intake bypass passage 35 is connected to the intake passage 21 on the upstream side of the circulation passage 45, while on the downstream of the supercharger 24, the circulation passage 45 is connected. Also, the intake bypass passage 35 is connected to the intake passage 21 on the downstream side. The connection locations of the intake bypass passage 35 and the circulation passage 45 in the upstream and downstream of the supercharger 24 are not limited to this. For example, the circulation passage 45 is connected to the intake passage 21 upstream of the intake bypass passage 35 upstream of the supercharger 24, while the intake bypass passage is downstream of the supercharger 24. Alternatively, the circulation passage 45 may be connected to the intake passage 21 on the further downstream side than the 35. Further, the intake bypass passage 35 is connected to the intake passage 21 upstream of the circulation passage 45 upstream of the supercharger 24, while the intake bypass passage is downstream of the supercharger 24. Alternatively, the circulation passage 45 may be connected to the intake passage 21 on the further downstream side than the 35. Further, the upstream side of the supercharger 24 is configured such that the circulation passage 45 is connected to the intake passage 21 upstream of the intake bypass passage 35, while the circulation passage 45 is downstream of the supercharger 24. Alternatively, the intake bypass passage 35 may be connected to the intake passage 21 on the downstream side.

  The second PCV valve 42 is arranged on the upstream side of the first PCV passage 41 and at a position close to the oil separator 40. Alternatively, the second PCV valve 42 may be disposed in the middle of the first PCV passage 41. Depending on such a form, when the engine stop pre-processing is executed as described above, the second PCV valve 42 is fully closed, so that the first PCV passage 41 upstream of the second PCV valve 42 is obtained. There is a risk that blow-by gas may stay in the tank. Considering these points, when the present embodiment is adopted as the location where the second PCV valve 42 is disposed, the connection location with the oil separator 40 is more gravity than the location where the second PCV valve 42 is disposed. It is desirable to provide the first PCV passage 41 so as to be located on the lower side in the direction. By providing the first PCV passage 41 in such a form, even if blowby gas stays in the upstream portion of the second PCV valve 42 in the first PCV passage 41, the staying blowby gas is stored in the crankcase 14. Can be returned.

  In step S110 of FIG. 2, the internal combustion engine 10 is stopped when either “condition A” is satisfied or “condition B” or “condition C” is satisfied. I was trying to judge that it was just before. It is also possible to determine that the internal combustion engine 10 is just before the stop with a combination of establishment / non-establishment of “condition A”, “condition B”, and “condition C”. For example, a condition for making such a determination may be that any one of “condition A”, “condition B”, and “condition C” is satisfied, and “condition A” and “condition B” are both satisfied. Or that “condition C” is satisfied may be satisfied. Furthermore, either “condition A” and “condition C” may be satisfied, or “condition B” may be satisfied, or “condition A” or “condition B”. In addition, all of the “condition C” may be satisfied.

  In step S110 in FIG. 2, parameters other than parameters such as the ignition off operation, vehicle speed, and shift position may be employed as parameters for determining whether or not the internal combustion engine 10 is just before stopping. For example, the engine speed and the fuel injection amount may be adopted as parameters, and it may be determined that the internal combustion engine 10 is about to stop when these are less than a predetermined value. In addition to the determination related to the parameters in this form, whether or not the internal combustion engine 10 is just before being stopped is determined by performing the determination related to the parameters such as the ignition off operation, the vehicle speed, and the shift position described in the above embodiment. You may make it judge.

  In step S130 of FIG. 2, the air bypass valve 36 is in the fully closed state, but instead, it may be in a substantially fully closed state in which the opening is slightly larger than in the fully closed state. Even in such a form, the effect that the blow-by gas staying in the circulation passage 45 and the ejector 50 can be scavenged more quickly can be obtained.

  In step S130 in FIG. 2, the waste gate valve 38 is in the fully closed state, but instead, it may be in a substantially fully closed state in which the opening is slightly larger than the fully closed state. Even in such a form, the effect that the blow-by gas staying in the circulation passage 45 and the ejector 50 can be scavenged more quickly can be obtained.

  In step S130 in FIG. 2, only the process related to the air bypass valve 36 may be performed. According to such a form, the effects (1) and (3) obtained by the above embodiment can be achieved.

  In step S130 in FIG. 2, only the processing related to the wastegate valve 38 may be performed. According to such a form, the effects (1) and (2) obtained by the above embodiment can be achieved.

-The process of step S130 of FIG. 2 may be omitted. According to such a form, the effect (1) obtained by the said embodiment can be show | played.
In step S120 in FIG. 2, the second PCV valve 42 is in a fully closed state. Instead, the second PCV valve 42 is almost fully closed in a state where the opening is slightly larger than the fully closed state. You may make it the state of this. Even in such a form, the blow-by gas staying in the circulation passage 45 or the ejector 50 can be scavenged by the air flowing through the circulation passage 45 while restricting the introduction of a new blow-by gas into the circulation passage 45 or the ejector 50. Such an effect can be obtained.

  In step S120 of FIG. 2, the first PCV valve 56 is in a fully open state. Instead, the first PCV valve 56 is in a substantially fully open state in which the opening is slightly smaller than the fully open state. You may make it do. Even in such a form, it is possible to obtain an effect that the blow-by gas can be prevented from flowing back into the outside air introduction passage 52 immediately before the internal combustion engine 10 is stopped.

  In step S120 of FIG. 2, the throttle valve 32 is in a fully closed state, but instead, the throttle valve 32 is in a substantially fully closed state in which the opening is slightly larger than the fully closed state. May be. Even in such a form, the effect that the blow-by gas staying in the circulation passage 45 and the ejector 50 can be introduced into the intake passage 21 earlier, and the back flow of the blow-by gas in the outside air introduction passage 52 are suitably suppressed. The effect that it becomes possible to do is acquired.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Cylinder block, 12 ... Cylinder head, 13 ... Head cover, 14 ... Crankcase, 15 ... Oil pan, 16 ... Cylinder, 17 ... Piston, 21 ... Intake passage, 22 ... Exhaust passage, 23 ... Station Passage, 24 ... turbocharger, 25 ... compressor, 26 ... compressor impeller, 27 ... shaft, 28 ... turbine, 29 ... turbine wheel, 30 ... air cleaner, 31 ... intercooler, 32 ... throttle valve, 33 ... throttle motor, 34 DESCRIPTION OF SYMBOLS ... Surge tank, 35 ... Intake bypass passage, 36 ... Air bypass valve, 37 ... Exhaust bypass passage, 38 ... Wastegate valve, 40 ... Oil separator, 41 ... First PCV passage, 42 ... Second PCV valve, 45 ... circulation passage, 46 ... inflow passage, 47 ... discharge passage, 50 ... ejector 52 ... air introduction passage 55: second PCV passage 56 ... first PCV valve, 60 ... controller, 64 ... ignition switch, 65 ... vehicle speed sensor, 66: shift lever 67: shift position sensor.

Claims (3)

A circulation passage for circulating the intake air from downstream to upstream of the supercharger in the intake passage; an ejector provided in the circulation passage; a first PCV passage communicating the ejector and the inside of the crankcase; and the intake passage An outside air introduction passage through which the upstream of the supercharger communicates with the crankcase and introduces outside air into the crankcase; a downstream of a throttle valve located downstream of the supercharger; and an interior of the crankcase A blow-by gas processing apparatus for an internal combustion engine having a second PCV passage communicating with the first PCV valve and a first PCV valve for adjusting a flow area of the second PCV passage,
A second PCV valve for opening and closing the first PCV passage;
Prior to the engine being stopped, engine stop pre-processing is performed in which the second PCV valve is closed, the first PCV valve is opened, and the throttle valve is closed. A blow-by gas processing apparatus for an internal combustion engine. The blow-by gas processing apparatus for an internal combustion engine according to claim 1,
An exhaust bypass passage communicating the upstream and downstream of the supercharger in the exhaust passage, and an exhaust bypass valve opening and closing the exhaust bypass passage;
The blow-by gas processing apparatus for an internal combustion engine, wherein the exhaust bypass valve is closed in conjunction with the execution of the pre-engine stop process before the engine is stopped. The blow-by gas processing apparatus for an internal combustion engine according to claim 1 or 2,
An intake bypass passage that communicates the upstream and downstream of the turbocharger in the intake passage, and an intake bypass valve that opens and closes the intake bypass passage;
The blow-by gas processing apparatus for an internal combustion engine, wherein the intake bypass valve is closed in conjunction with the execution of the pre-engine stop process before the engine is stopped.