JP6005592B2 - Blow-by gas reduction device for supercharged engine - Google Patents

Description

  The present invention relates to a blow-by gas reduction device for a supercharged engine, which is provided in a supercharged engine having a supercharger in an intake passage and reduces blowby gas generated in the engine to the engine through the intake passage.

  Conventionally, as this type of technology, Patent Document 1 discloses that a negative pressure is generated in a first blow-by gas reduction passage connected to a surge tank and a bypass passage connecting the upstream side and the downstream side of the turbocharger. A blow-by gas reduction device having an ejector (jet pump) and a second blow-by gas reduction passage connected to the ejector is disclosed.

JP 2009-299645 A

  Here, in the blow-by gas reduction device disclosed in Patent Document 1, the negative pressure generated in the intake passage on the downstream side of the throttle valve acts on the first blow-by gas reduction passage, so that the blow-by gas is introduced into the first blow-by gas reduction passage. Flows. Moreover, blow-by gas flows through the second blow-by gas reduction passage by the negative pressure generated in the ejector acting on the second blow-by gas reduction passage. As described above, in the blow-by gas reduction device of Patent Document 1, the flow rate of the blow-by gas flowing through each blow-by gas reduction passage depends on the magnitude of the negative pressure downstream of each blow-by gas reduction passage. Therefore, depending on the operating range of the engine, there is a possibility that the reduction flow rate of blow-by gas to the engine may not be appropriate, for example, the reduction flow rate of blow-by gas to the engine becomes excessive.

  Accordingly, the present invention has been made to solve the above-described problems, and is provided with a blow-by gas reduction device for a supercharged engine capable of appropriately adjusting the reduction flow rate of blow-by gas to the engine according to the engine operating range. It is an issue to provide.

One aspect of the present invention made to solve the above-described problems is a blow-by of an engine with a supercharger that is provided in an engine having a supercharger in an intake passage and that reduces blow-by gas generated in the engine to the engine. In the gas reduction device, a first blow-by gas reduction portion having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine, and an upstream side of the supercharger in the intake passage A bypass passage connected to the downstream side, an ejector for generating a negative pressure in the bypass passage, and a second blowby gas reduction passage communicating with the ejector and the crankcase And at least one of the first blow-by gas reduction unit and the second blow-by gas reduction unit The reduction rate of the blow-by gas have a, and a control unit for controlling in accordance with the operating region of the engine by the second blow-by gas returning section includes blocking the communicating of the bypass passage or the second blow-by gas returning passage The control unit controls opening and closing of the second switching valve according to the operating range of the engine, and the control unit is configured such that the operating range of the engine is close to a supercharging range. When the engine speed is higher than a predetermined speed, the second switching valve is closed .

According to this aspect, the control unit controls the reduction flow rate of the blowby gas through the blowby gas reduction passage according to the engine operating range, so the blowby gas reduction flow rate to the engine is appropriately adjusted according to the engine operating range. it can. Further, the communication between the bypass passage or the second blow-by gas reduction passage and the cutoff thereof can be switched according to the operating range of the engine. Therefore, the reduction flow rate of blow-by gas to the engine is more appropriately adjusted according to the operating range of the engine. Further, the blow-by gas is not reduced from the crankcase to the intake passage via the second blow-by gas reduction passage. Therefore, the reduction flow rate of blow-by gas to the engine is suppressed. Therefore, when the engine operating range is close to the supercharging range and the engine speed is higher than the predetermined speed, the reduction flow rate of the blow-by gas to the engine does not become excessive. Therefore, according to this aspect, it is possible to prevent an increase in the amount of engine oil taken away from the engine.

  In the above aspect, the first blow-by gas reduction unit includes a first switching valve that switches between communication and blocking of the first blow-by gas reduction passage, and the control unit performs the operation according to the operating range of the engine. It is preferable to control the opening and closing of the first switching valve.

  According to this aspect, it is possible to switch between communication and blocking of the first blow-by gas reduction passage according to the operating range of the engine. Therefore, the reduction flow rate of blow-by gas to the engine is more appropriately adjusted according to the operating range of the engine.

  In the above aspect, it is preferable that the control unit closes the first switching valve when the operating range of the engine is in a supercharging range and immediately after deceleration.

  According to this aspect, blow-by gas is not reduced from the crankcase to the intake passage via the first blow-by gas reduction passage. Therefore, the reduction flow rate of blow-by gas to the engine is suppressed. Therefore, when the engine operating region is in the supercharging region and immediately after deceleration, the exhaust gas remaining in the engine is difficult to return to the engine together with the blow-by gas, and the ratio of the exhaust gas in the engine combustion chamber becomes excessive. Don't be. Therefore, according to this aspect, it is possible to prevent the occurrence of engine misfire.

Another aspect of the present invention made to solve the above problems is an engine with a supercharger that is provided in an engine having a supercharger in an intake passage and that reduces blow-by gas generated in the engine to the engine. In the blow-by gas reduction device, a first blow-by gas reduction portion having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine, and upstream of the supercharger in the intake passage A second blow-by gas comprising a bypass passage connected to the side and the downstream side, an ejector for generating a negative pressure in the bypass passage, and a second blow-by gas reduction passage communicating with the ejector and the crankcase At least one of a reducing unit and the first blow-by gas reducing unit or the second blow-by gas reducing unit A control unit that controls the reduction flow rate of the blowby gas according to the operating range of the engine, and the control unit performs control to reduce the reduction flow rate of the blowby gas to the engine immediately after deceleration, An amount and a time for restricting the reduction flow rate of the blow-by gas are determined according to a residual ratio of exhaust gas in the crankcase.

According to this aspect, the control unit controls the reduction flow rate of the blowby gas through the blowby gas reduction passage according to the engine operating range, so the blowby gas reduction flow rate to the engine is appropriately adjusted according to the engine operating range. it can. Further, immediately after the vehicle decelerates, the proportion of exhaust gas in the combustion chamber can be suppressed, so that it is possible to prevent engine misfire.

Another aspect of the present invention made to solve the above problems is an engine with a supercharger that is provided in an engine having a supercharger in an intake passage and that reduces blow-by gas generated in the engine to the engine. In the blow-by gas reduction device, a first blow-by gas reduction portion having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine, and upstream of the supercharger in the intake passage A second blow-by gas comprising a bypass passage connected to the side and the downstream side, an ejector for generating a negative pressure in the bypass passage, and a second blow-by gas reduction passage communicating with the ejector and the crankcase At least one of a reducing unit and the first blow-by gas reducing unit or the second blow-by gas reducing unit A control unit for controlling the flow rate of the blow-by gas reduced according to the operating range of the engine, wherein the first blow-by gas reduction unit switches between communication and blocking of the first blow-by gas reduction passage. 1 switching valve, the control unit controls the opening and closing of the first switching valve according to the operating range of the engine, the second blowby gas reduction unit is the bypass passage or the second blowby gas reduction passage A second switching valve that switches between communication and shut-off, and the control unit controls opening and closing of the second switching valve according to an operating range of the engine, and the first switching valve and the second switching valve are It is characterized by being integrated .

According to this aspect, the control unit controls the reduction flow rate of the blowby gas through the blowby gas reduction passage according to the engine operating range, so the blowby gas reduction flow rate to the engine is appropriately adjusted according to the engine operating range. it can. Further, the communication between the first blow-by gas reduction passage and the shut-off can be switched according to the operating range of the engine. Therefore, the reduction flow rate of blow-by gas to the engine is more appropriately adjusted according to the operating range of the engine. Further, communication between the flow path of the blow-by gas in the first blow-by gas reduction section and the second blow-by gas reduction section can be switched between and blocked according to the operating range of the engine. Therefore, the reduction flow rate of blow-by gas to the engine is more appropriately adjusted according to the operating range of the engine. In addition, since the first switching valve and the second switching valve are integrated, the number of parts is reduced. Therefore, according to this aspect, cost can be reduced.

Another aspect of the present invention made to solve the above problems is an engine with a supercharger that is provided in an engine having a supercharger in an intake passage and that reduces blow-by gas generated in the engine to the engine. In the blow-by gas reduction device, a first blow-by gas reduction portion having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine, and upstream of the supercharger in the intake passage A second blow-by gas comprising a bypass passage connected to the side and the downstream side, an ejector for generating a negative pressure in the bypass passage, and a second blow-by gas reduction passage communicating with the ejector and the crankcase At least one of a reducing unit and the first blow-by gas reducing unit or the second blow-by gas reducing unit And a control unit for controlling in accordance with the operation range of the reduction rate the engine of the blow-by gas by a communication path provided between the surge tank and the bypass passage, controlling the flow rate of said communicating passage And a flow rate control valve .

According to this aspect, the control unit controls the reduction flow rate of the blowby gas through the blowby gas reduction passage according to the engine operating range, so the blowby gas reduction flow rate to the engine is appropriately adjusted according to the engine operating range. it can. Moreover, the flow rate of the flow path of the blow-by gas in the second blow-by gas reduction unit can be controlled according to the engine operating range. Therefore, the reduction flow rate of blow-by gas to the engine is more appropriately adjusted according to the operating range of the engine.

  In the above aspect, it is preferable that the flow control valve is opened when the operating range of the engine is close to a supercharging range and the engine speed is higher than a predetermined speed.

  According to this aspect, since the flow rate of the air flowing into the ejector is suppressed, the reduction flow rate of the blowby gas in the second blowby gas reduction passage is suppressed. Therefore, the reduction flow rate of blow-by gas to the engine is suppressed. Therefore, when the engine operating range is close to the supercharging range and the engine speed is higher than the predetermined speed, the reduction flow rate of the blow-by gas to the engine does not become excessive. Therefore, according to this aspect, it is possible to prevent an increase in the amount of engine oil taken away from the engine.

  According to the blow-by gas reduction device for a supercharged engine of the present invention, the reduction flow rate of blow-by gas to the engine can be appropriately adjusted according to the operating range of the engine.

1 is a schematic configuration diagram illustrating an engine system including a blow-by gas reduction device according to Embodiment 1. FIG. It is sectional drawing which shows schematic structure of a variable PCV valve | bulb. It is sectional drawing which shows schematic structure of an ejector. It is a figure which shows a response | compatibility with the operating condition area | region in Example 1, and opening and closing of VSV. It is a flowchart which shows the control program which ECU runs. It is a figure which shows an example of the map of PCV opening degree. It is a figure which shows an example of the map of the residual exhaust gas rate counter value in a crankcase. FIG. 6 is a relationship diagram between an accumulated crankcase exhaust gas amount and a PCV opening correction coefficient. It is a figure which shows VSV of Example 2, and shows the state which the compressor and ejector of a supercharger connect. It is a figure which shows the VSV of Example 2, and shows the state which a crankcase and a surge tank communicate. FIG. 5 is a diagram illustrating a VSV of a second embodiment, in which a compressor and an ejector of a supercharger communicate with each other and a crankcase and a surge tank communicate with each other. It is a schematic block diagram which shows the engine system containing the blowby gas reducing apparatus of Example 3. It is a figure which shows that a flow control valve is a valve opening state. It is a figure which shows that a flow control valve is a valve closing state. It is a figure which shows that a flow control valve is a valve closing state. It is a figure which shows a response | compatibility with the operating condition area | region in Example 3, and opening and closing of VSV. FIG. 10 is a schematic configuration diagram illustrating an engine system including a blow-by gas reduction device according to a modification of the third embodiment. It is a graph which shows the characteristic of the reduction | restoration flow rate of blow-by gas.

  Embodiments of an engine system including a blow-by gas reduction device according to the present invention will be described below with reference to the drawings.

<Example 1>
[Engine system configuration]
FIG. 1 is a schematic configuration diagram showing an engine system including a blow-by gas reduction device for a supercharged engine in this embodiment. This engine system includes a reciprocating engine 1. An intake passage 3 is connected to the intake port 2 of the engine 1, and an exhaust passage 5 is connected to the exhaust port 4. An air cleaner 6 is provided at the inlet of the intake passage 3. A supercharger 7 for boosting the intake air in the intake passage 3 is provided between the exhaust passage 5 and the intake passage 3 downstream of the air cleaner 6.

  The supercharger 7 includes a compressor 8 disposed in the intake passage 3, a turbine 9 disposed in the exhaust passage 5, and a rotating shaft 10 that connects the compressor 8 and the turbine 9 so as to be integrally rotatable. The supercharger 7 rotates the turbine 9 with the exhaust gas flowing through the exhaust passage 5 and integrally rotates the compressor 8 via the rotary shaft 10, thereby boosting the intake air in the intake passage 3, that is, performing supercharging. It has become.

  An exhaust bypass passage 11 that bypasses the turbine 9 is provided in the exhaust passage 5 adjacent to the supercharger 7. A waste gate valve 12 is provided in the exhaust bypass passage 11. The opening degree of the wastegate valve 12 is adjusted by a diaphragm actuator 13. By adjusting the exhaust gas flowing through the exhaust bypass passage 11 by the wastegate valve 12, the flow rate of the exhaust gas supplied to the turbine 9 is adjusted, and the rotational speeds of the turbine 9 and the compressor 8 are adjusted. The supercharging pressure is adjusted.

  In the intake passage 3, an intercooler 14 is provided between the compressor 8 of the supercharger 7 and the engine 1. The intercooler 14 is for cooling the intake air whose pressure has been increased by the compressor 8 to an appropriate temperature. A surge tank 3 a is provided in the intake passage 3 between the intercooler 14 and the engine 1. A throttle valve 15 is provided on the upstream side of the surge tank 3a. The engine 1 also includes a head cover 16, a crankcase 17, a combustion chamber 18, and the like.

  The ECU 19 includes a microcomputer (microcomputer) that performs electronic control of each part of the engine system. As is well known, this microcomputer includes a central processing unit (CPU), a read / write memory (RAM), a read only memory (ROM), and the like, and performs processing of signals input to the ECU 19 and the like.

  The ECU 19 is connected to various sensors, switches, and the like, and receives, for example, the engine speed ne, the engine load kl, the opening of the variable PCV valve 32 (PCV opening tp), and the like as input data. ing. The ECU 19 also serves as a “control unit” in the present invention. As will be described in detail later, the ECU 19 controls the reduction flow rate of blow-by gas in at least one of the first blow-by gas reduction unit 20 and the second blow-by gas reduction unit 22 according to the operating range of the engine 1. .

  As shown in FIG. 1, the blow-by gas reduction apparatus of the present embodiment includes a first blow-by gas reduction unit 20 and a second blow-by gas reduction unit 22. The first blow-by gas reduction unit 20 includes a first blow-by gas reduction passage 30, a variable PCV valve 32, a VSV 34, and the like. The second blow-by gas reduction unit 22 includes an intake bypass passage 40, an ejector 42, a second blow-by gas reduction passage 44, a VSV 46, and the like.

  The first blow-by gas reduction passage 30 communicates with the surge tank 3 a and the crankcase 17. Specifically, the inlet of the first blow-by gas reduction passage 30 is connected to the head cover 16 of the engine 1. Here, the first blow-by gas reduction passage 30 is a passage for returning blow-by gas leaked from the combustion chamber 18 of the engine 1 into the crankcase 17 to the combustion chamber 18 again via the intake passage 3. It is. The outlet of the first blow-by gas reduction passage 30 is connected to the surge tank 3 a of the intake passage 3. Further, a variable PCV valve 32 as shown in FIG. 2 is provided at the inlet of the first blow-by gas reduction passage 30 in the head cover 16.

  As shown in FIG. 2, the variable PCV valve 32 includes a body 50, a valve body 52, a spring 54, a step motor 56, and the like. The body 50 includes a suction port 50a, a valve chamber 50b, a discharge port 50c, a seat (valve seat) 50d, and the like. The valve body 52 and the spring 54 are disposed in the valve chamber 50 b of the body 50. Then, when the step motor 56 is driven, the valve body 52 moves in the axial direction against the urging force of the spring 54 and contacts and separates from the seat 50d, whereby the valve body 52 is opened and closed. The blow-by gas enters from the suction port 50a, passes through the valve chamber 50b, and is discharged from the discharge port 50c. The discharge amount of blow-by gas is adjusted by the opening / closing operation of the valve body 52 by driving the step motor 56.

  The VSV 34 is a switching valve that is provided in the first blow-by gas reduction passage 30 and switches between communication and blocking of the first blow-by gas reduction passage 30. As will be described in detail later, the ECU 19 controls the opening and closing of the VSV 34 according to the operating range of the engine 1. The VSV 34 is an example of the “first switching valve” in the present invention.

  The intake bypass passage 40 is connected to the upstream side and the downstream side of the supercharger 7 in the intake passage 3. That is, an intake bypass passage 40 that bypasses the compressor 8 is provided between the intake passage 3 immediately downstream of the compressor 8 where the supercharging pressure becomes high and the intake passage 3 upstream of the compressor 8. The intake bypass passage 40 is provided with an ejector 42 that generates a negative pressure in the passage 40. The intake bypass passage 40 is an example of the “bypass passage” in the present invention.

  FIG. 3 shows a schematic configuration of the ejector 42 in a cross-sectional view. As shown in FIG. 3, the ejector 42 includes a nozzle 42a provided on the air inlet side, a diffuser 42b provided on the air outlet side, and a decompression chamber 42c provided between the nozzle 42a and the diffuser 42b. Prepare. The ejector 42 generates a negative pressure in the decompression chamber 42c by the air ejected from the nozzle 42a.

  That is, when the turbocharger 7 is operated, the pressure of the intake air is increased by the compressor 8, so that a pressure difference is generated between the intake passage 3 upstream of the compressor 8 and the intake passage 3 downstream of the compressor 8. . For this reason, different intake pressures (driving pressures) act between the nozzle 42 a and the diffuser 42 b of the ejector 42 through the intake bypass passage 40. Due to this pressure difference, air is ejected from the nozzle 42a toward the diffuser 42b, thereby generating a negative pressure in the decompression chamber 42c. The magnitude of this negative pressure changes according to the magnitude of the supercharging pressure by the supercharger 7.

  The second blow-by gas reduction passage 44 communicates with the ejector 42 and the crankcase 17. Specifically, the outlet of the second blow-by gas reduction passage 44 is connected to the decompression chamber 42c (see FIG. 3) of the ejector 42. The inlet of the second blow-by gas reduction passage 44 is connected to the head cover 16 of the engine 1. The second blow-by gas reduction passage 44 is a passage for reducing blow-by gas leaked from the combustion chamber 18 of the engine 1 into the crankcase 17 from the head cover 16 to the combustion chamber 18 via the intake passage 3 again. It is.

  The ejector 42 includes a valve 42d that adjusts the air flow rate. Since the ejector 42 includes the valve 42d, even if the pressure of the working fluid (air) increases, the ejector 42 can suppress the increase in the flow rate of the working fluid and suppress the generation of negative pressure. Therefore, the flow rate of the blowby gas in the second blowby gas reduction passage 44 is suppressed from increasing more than necessary.

  The VSV 46 is a switching valve that is provided in the passage 40a on the upstream side (intercooler 14 side) of the intake bypass passage 40 with respect to the ejector 42 and switches between blocking and communication of the passage 40a. Then, as will be described in detail later, the ECU 19 controls the opening and closing of the VSV 46 in accordance with the operating range of the engine 1. The VSV 46 is an example of the “second switching valve” in the present invention.

  A fresh air introduction passage 58 for introducing fresh air into the head cover 16 and the crankcase 17 is provided between the engine 1 and the intake passage 3. The inlet of the fresh air introduction passage 58 is connected to the intake passage 3 near the air cleaner 6, and the outlet thereof is connected to the head cover 16. The head cover 16 and the crankcase 17 communicate with each other via a communication path (not shown) provided in the engine 1.

  The above-described blow-by gas reduction device for a supercharged engine in the present embodiment operates as follows when the VSV 34 and the VSV 46 are both opened as a basic operation.

  First, when the engine 1 is in operation and the supercharger 7 is not operating, negative pressure generated in the intake passage 3 (surge tank 3a) downstream of the throttle valve 15 is generated in the first blow-by gas reduction passage 30. Works. Due to the negative pressure, the blow-by gas accumulated in the head cover 16 flows to the intake passage 3 through the variable PCV valve 32 and the first blow-by gas reduction passage 30. As a result, when the supercharger 7 is not in operation, the blow-by gas in the head cover 16 can be reduced to the combustion chamber 18 through the intake passage 3.

  On the other hand, when the engine 1 is in operation and the supercharger 7 is operating, the intake passage 3 downstream from the supercharger 7 is at a high pressure, so that negative pressure acts on the outlet of the first blow-by gas reduction passage 30. No longer. For this reason, the blow-by gas does not flow from the head cover 16 to the intake passage 3 through the variable PCV valve 32 and the first blow-by gas reduction passage 30.

  At this time, a pressure difference occurs in the intake air between the intake passage 3 upstream of the supercharger 7 and the intake passage 3 downstream, and a pressure difference also occurs between the both ends of the intake bypass passage 40. Due to this pressure difference, air flows through the intake bypass passage 40, and this air flow generates a negative pressure at the ejector 42. Therefore, negative pressure by the ejector 42 acts on the outlet of the second blow-by gas reduction passage 44, and blow-by gas accumulated in the head cover 16 passes through the second blow-by gas reduction passage 44, the ejector 42, and the intake bypass passage 40. It flows to the intake passage 3. As a result, when the supercharger 7 is in operation, the blow-by gas in the head cover 16 can be reduced to the combustion chamber 18 through the intake passage 3.

  Further, when the supercharging pressure by the supercharger 7 increases, the pressure difference between both ends of the intake bypass passage 40 increases, and the negative pressure generated by the ejector 42 increases accordingly. For this reason, the flow rate of the blowby gas flowing from the head cover 16 to the intake passage 3 via the second blowby gas reduction passage 44 and the like increases, and the blowby gas reduced to the combustion chamber 18 increases.

  Further, when the blow-by gas accumulated in the head cover 16 flows from the inlet of the first blow-by gas reduction passage 30 or from the inlet of the second blow-by gas reduction passage 44 toward the intake passage 3, the head cover 16. The fresh air is introduced through the fresh air introduction passage 58 from the outside. Therefore, the inside of the head cover 16 and the inside of the crankcase 17 can be ventilated by fresh air introduced into the head cover 16.

  The above is the description of the configuration of the engine system and its basic operation.

[Operation of blow-by gas reduction device in this embodiment]
Next, as a function of the blow-by gas reduction device in the present embodiment, a method for controlling the reduction flow rate of the blow-by gas performed by the ECU 19 will be described in detail. In this embodiment, the ECU 19 controls the opening and closing of each of the VSV 34 and the VSV 46 as shown in FIG. FIG. 4 shows how the VSV 34 and VSV 46 open and close corresponding to operating condition areas A1 to A3 described later.

  Here, in FIG. 18, in the blow-by gas reduction device of the comparative example, the intake pipe pressure (pressure in the surge tank 3 a), the drive pressure of the ejector 42 (intake pressure), and the reduction flow rate of the blow-by gas to the engine 1 are shown. The graph showing the characteristic of the reduction | restoration flow rate of the blowby gas which shows a relationship is shown. Here, it is assumed that the blow-by gas reduction device of the comparative example does not include the VSV 34, the VSV 46, and the variable PCV valve 32 as main points different from the blow-by gas reduction device of the present embodiment.

  Then, as shown in FIG. 18, when the engine 1 is in the operating region near the supercharging region, that is, in the region where the intake pipe pressure is about −20 kPa to about 0 kPa, the first blow-by gas The blow-by gas is reduced to the engine 1 by the reduction unit 20. At this time, when the engine speed ne is high, the drive pressure of the ejector 42 is generated, and a large amount of blow-by gas is reduced to the engine 1 by the second blow-by gas reduction unit 22. Therefore, the reduction flow rate of blow-by gas to the engine 1 becomes excessive (indicated as “excessive flow rate” in FIG. 18). Therefore, a large amount of engine oil in the crankcase 17 may be taken out of the crankcase 17 together with the blow-by gas.

  Therefore, in the present embodiment, the ECU 19 performs the operation shown in FIG. 4 when the operating range of the engine 1 is close to the supercharging range and the engine speed ne is higher than a predetermined speed (operating condition range A1). As shown, VSV 34 is opened, and VSV 46 is closed. As a result, the drive pressure of the ejector 42 is not generated, so that the blow-by gas is not reduced to the engine 1 by the second blow-by gas reduction unit 22. Therefore, the reduction flow rate of blow-by gas to the engine 1 is suppressed. Therefore, it is possible to prevent an increase in the amount of engine oil taken away from the crankcase 17.

  Further, when the vehicle decelerates when the engine 1 is in the supercharging region, the supply of intake air to the combustion chamber decreases immediately after deceleration, so that the exhaust gas remaining in the engine 1 is sent to the engine 1 together with the blow-by gas. When refluxed, the ratio of exhaust gas in the combustion chamber 18 will increase. And when the ratio of the exhaust gas in the combustion chamber 18 becomes large in this way, the engine 1 may be misfired.

  Therefore, in this embodiment, the ECU 19 closes the VSV 34 as shown in FIG. 4 when the engine 1 is in the supercharging region and immediately after the vehicle decelerates (operating condition region A2). VSV 46 is opened. Thereby, the blow-by gas is not reduced to the engine 1 by the first blow-by gas reduction unit 20. Therefore, the reduction flow rate of blow-by gas to the engine 1 is suppressed. Therefore, the exhaust gas remaining in the engine 1 is hardly recirculated to the engine 1 together with the blow-by gas, and the ratio of the exhaust gas in the combustion chamber 18 does not become excessive. Therefore, misfire of the engine 1 does not occur.

  At this time, since the engine 1 is in the light load region, the pressure difference of the intake air is small between both ends of the intake bypass passage 40, and no negative pressure is generated in the ejector 42. Therefore, even if the VSV 46 is opened, the blow-by gas is not reduced to the engine 1 by the second blow-by gas reduction unit 22. Therefore, the reduction flow rate of the blow-by gas to the intake passage 3 is reliably suppressed. The VSV 46 may be closed.

  Note that when the engine 1 is in an operating range (operating condition range A3) other than the above (operating condition range A1 and operating condition range A2), the ECU 19 sets both the VSV 34 and VSV 46 to the open state as shown in FIG. To do.

  Further, when the engine 1 is in the supercharging region and immediately after the vehicle decelerates (operating condition region A2), the ECU 19 opens both the VSV 34 and the VSV 46, and further remains in the crankcase 17. The opening degree of the variable PCV valve 32 may be controlled according to the ratio of the exhaust gas. That is, the ECU 19 controls the flow area of the first blowby gas reduction passage 30 by the variable PCV valve 32 according to the ratio of the exhaust gas remaining in the crankcase 17 (reduction flow rate of blowby gas in the first blowby gas reduction unit 20). ) To control the amount and time to squeeze. Specifically, the ECU 19 performs a routine process of a control program shown in FIG.

  Therefore, the routine process shown in FIG. 5 will be described. The ECU 19 periodically executes the routine process shown in FIG. 5 every predetermined time.

  Therefore, when the routine shown in FIG. 5 is started, the ECU 19 first takes in the engine speed ne and the engine load kl (step S1), and opens the PCV based on the taken-in engine speed ne and the engine load kl. The degree tp is obtained (step S2). At this time, ECU19 calculates | requires PCV opening degree tp, for example using a map figure as shown in FIG. Here, the PCV opening degree tp is the opening degree of the variable PCV valve 32. The engine load kl is a value based on any of the accelerator opening, the throttle opening, the intake air amount, the intake pipe pressure, and the like.

  Next, the ECU 19 obtains a residual exhaust gas rate counter value ce in the crankcase 17 based on the taken-in engine speed ne and engine load kl (step S3). At this time, the ECU 19 obtains the residual exhaust gas rate counter value ce using, for example, a map diagram as shown in FIG.

Next, the ECU 19 calculates an integrated crankcase exhaust gas amount CE (i) (step S4). Here, the cumulative crankcase exhaust gas amount CE (i) is obtained from the following equation.
[Equation 1]
CE (i) = CE (i-1) + ce

  Next, the ECU 19 determines whether or not the cumulative crankcase exhaust gas amount CE (i) is greater than a predetermined amount A (step S5). When the cumulative crankcase exhaust gas amount CE (i) is larger than the predetermined amount A, the ECU 19 sets the cumulative crankcase exhaust gas amount CE (i) to the predetermined amount A (step S6).

  Next, the ECU 19 determines whether or not the engine load kl is less than 20% (step S7). When the engine load kl is less than 20%, the ECU 19 obtains a PCV opening correction coefficient ke corresponding to the cumulative crankcase exhaust gas amount CE (i) (step S8). The ECU 19 obtains the PCV opening correction coefficient ke using, for example, a relationship diagram as shown in FIG. As shown in FIG. 8, the PCV opening correction coefficient ke decreases as the cumulative crankcase exhaust gas amount CE (i) increases.

Next, the ECU 19 obtains a final target PCV opening degree Tp (step S9). Here, the final target PCV opening Tp is obtained from the following equation.
[Equation 2]
Tp = (tp) × (ke)

  Next, the ECU 19 controls the opening degree of the variable PCV valve 32 to be the final target PCV opening degree Tp (step S10). In this way, the ECU 19 controls the opening degree of the variable PCV valve 32 according to the amount of exhaust gas in the crankcase 17. Specifically, the ECU 19 performs control so that the opening degree of the variable PCV valve 32 decreases as the amount of exhaust gas in the crankcase 17 increases.

  If the cumulative crankcase exhaust gas amount CE (i) is equal to or less than the predetermined amount A in step 5 and the cumulative crankcase exhaust gas amount CE (i) is less than 0 (step S11: YES). The ECU 19 sets the accumulated crankcase exhaust gas amount CE (i) to 0 (step S12), and proceeds to the control of step S7. On the other hand, when the cumulative crankcase exhaust gas amount CE (i) is not more than the predetermined amount A and the cumulative crankcase exhaust gas amount CE (i) is not less than 0 in step 5 (step S11: NO). Therefore, the ECU 19 proceeds to the control of step S7 as it is.

  When the engine load kl is 20% or more in step S7, the ECU 19 sets the final target PCV opening Tp as the PCV opening tp (step S13), and proceeds to the control in step S8.

  Each time the routine process shown in FIG. 5 is repeated, the ECU 19 obtains the cumulative crankcase exhaust gas amount CE (i), and the variable PCV valve increases as the cumulative crankcase exhaust gas amount CE (i) decreases. 32 reduces the amount by which the flow rate of the blow-by gas in the first blow-by gas reduction passage 30 is reduced. Here, as the flow rate of the blow-by gas in the first blow-by gas reduction passage 30 is reduced by the variable PCV valve 32, the decreasing speed of the cumulative crankcase exhaust gas amount CE (i) becomes slower. Therefore, in the blow-by gas reduction device of the present embodiment, as the cumulative crankcase exhaust gas amount CE (i) increases, the time for reducing the flow rate of the blow-by gas in the first blow-by gas reduction passage 30 by the variable PCV valve 32 is lengthened. be able to. In this way, when the ECU 19 performs control for reducing the reduction flow rate of the blowby gas to the intake passage 3 (engine 1) immediately after deceleration, the ECU 19 sets the amount and time for reducing the reduction flow rate of the blowby gas in the crankcase 17. Determined according to the residual rate of exhaust gas.

[Effect of this embodiment]
The blow-by gas reduction device of the present embodiment as described above is provided in the engine 1 having the supercharger 7 in the intake passage 3 and reduces the blow-by gas generated in the engine 1 to the engine 1. The blow-by gas reduction device of the present embodiment includes a first blow-by gas reduction unit 20 including a first blow-by gas reduction passage 30 that communicates with a surge tank 3 a provided in the intake passage 3 and a crankcase 17 of the engine 1. . The blow-by gas reduction device of this embodiment includes an intake bypass passage 40 connected to the upstream side and the downstream side of the supercharger 7 in the intake passage 3 and an ejector 42 for generating negative pressure in the intake bypass passage 40. And a second blow-by gas reduction section 22 having a second blow-by gas reduction passage 44 communicating with the ejector 42 and the crankcase 17. The blow-by gas reduction apparatus according to this embodiment includes an ECU 19 that controls a reduction flow rate of blow-by gas by at least one of the first blow-by gas reduction unit 20 and the second blow-by gas reduction unit 22 according to the operating range of the engine 1. Have

  Thus, since ECU19 controls the reduction | restoration flow rate of the blowby gas by the 1st blowby gas reduction | restoration part 20 and the 2nd blowby gas reduction | restoration part 22 according to the operating region of the engine 1, the reduction | restoration flow rate of the blowby gas to the engine 1 is controlled. It can be appropriately adjusted according to the operating range of the engine 1.

  Therefore, when the engine 1 is in the operating region near the supercharging region and the engine speed ne is high (in the “excessive flow” operating region in FIG. 18), the blow-by gas is reduced to the engine 1. It is possible to prevent the flow rate from becoming excessive. Therefore, an increase in the amount of engine oil taken away from the crankcase 17 can be prevented.

  Further, the ECU 19 controls to reduce the reduction flow rate of blow-by gas to the engine 1 immediately after deceleration, and determines the amount and time for reducing the reduction flow rate of blow-by gas according to the exhaust gas residual rate in the crankcase 17. Thereby, immediately after the vehicle decelerates, the proportion of the exhaust gas in the combustion chamber 18 can be suppressed, so that misfire of the engine 1 can be prevented.

  Further, the first blow-by gas reduction unit 20 includes a VSV 34 that switches between communication and blocking of the first blow-by gas reduction passage 30. Further, the second blow-by gas reduction unit 22 includes a VSV 46 that switches between communication and blocking of the intake bypass passage 40. The ECU 19 controls the opening and closing of the VSV 34 and the VSV 46 according to the operating range of the engine 1. Thereby, according to the operating region of the engine 1, the communication of the flow path of blow-by gas in the 1st blow-by gas reduction part 20 and the 2nd blow-by gas reduction part 22 can be switched. Therefore, the reduction flow rate of blow-by gas to the engine 1 can be appropriately adjusted according to the operating range of the engine 1 more reliably.

  Further, the ECU 19 closes the VSV 34 when the operating range of the engine 1 is in the supercharging range and immediately after the vehicle decelerates. As a result, blow-by gas is not reduced from the crankcase 17 to the intake passage 3 via the first blow-by gas reduction passage 30. Therefore, the reduction flow rate of blow-by gas to the engine 1 is suppressed. Therefore, the exhaust gas remaining in the engine 1 is hardly recirculated to the engine 1 together with the blow-by gas, and the ratio of the exhaust gas in the combustion chamber of the engine 1 does not become excessive. Therefore, the occurrence of misfire of the engine 1 can be prevented.

  Further, the ECU 19 closes the VSV 46 when the operating range of the engine 1 is close to the supercharging range and the engine speed ne is higher than a predetermined speed. As a result, blow-by gas is not reduced from the crankcase 17 to the intake passage 3 via the second blow-by gas reduction passage 44. Therefore, the reduction flow rate of blow-by gas to the engine 1 is suppressed. Therefore, when the operating range of the engine 1 is close to the supercharging region and the engine speed ne is higher than the predetermined engine speed, the reduction flow rate of the blow-by gas to the engine 1 does not become excessive. Therefore, an increase in the amount of engine oil taken away from the crankcase 17 can be prevented.

  As a modification, for example, the VSV 46 may be provided in the second blow-by gas reduction passage 44 instead of being provided in the intake bypass passage 40. Further, the blow-by gas reduction device may include only one of VSV 34 and VSV 46. Further, the ECU 19 controls the VSV 34 to be closed as shown in FIG. 4 and opens the VSV 34 when the operating range of the engine 1 is in the supercharging range and immediately after the vehicle decelerates. As shown in FIG. 5, control for adjusting the opening degree of the variable PCV valve 32 may be selected as appropriate.

<Example 2>
Next, the second embodiment will be described. The same components as those of the first embodiment are denoted by the same reference numerals, the description thereof will be omitted, and different points will be mainly described.

  The blow-by gas reduction apparatus of the second embodiment is different from the first embodiment in that it has one VSV 60 as shown in FIGS. 9 to 11 instead of the VSV 34 and the VSV 46. The VSV 60 is a switching valve that can perform both switching between communication and blocking in the first blow-by gas reduction passage 30 and switching between communication and blocking in the intake bypass passage 40. That is, the VSV 60 corresponds to a combination of the VSV 34 and the VSV 46.

  The VSV 60 includes a first valve body 64, a second valve body 66, a motor 68, a spring 70, and the like inside the housing 62. The housing 62 can communicate with the crankcase 17, the surge tank 3 a, the compressor 8, and the ejector 42. The first valve body 64 and the second valve body 66 are integrally connected by a shaft 72. By driving the motor 68, the shaft 72 is moved in the direction of the central axis, and the first valve body 64 and the second valve body 66 are moved in the direction of the central axis of the shaft 72. The spring 70 is provided between the inner surface of the housing 62 and the first valve body 64. The VSV 60 includes a partition 73 in the housing 62. The partition 73 partitions the communication path between the crankcase 17 and the surge tank 3a and the communication path between the compressor 8 and the ejector 42.

  In the VSV 60 having such a configuration, the first valve body 64 is urged toward the motor 68 by the spring 70. The first valve body 64 and the second valve body 66 can be moved by the motor 68 against the urging force of the spring 70. As a result, as shown in FIG. 9, the compressor 8 and the ejector 42 communicate with each other, while the crankcase 17 and the surge tank 3a are shut off. Further, as shown in FIG. 10, the crankcase 17 and the surge tank 3a communicate with each other, while the compressor 8 and the ejector 42 are shut off. Furthermore, as shown in FIG. 11, the crankcase 17 and the surge tank 3a communicate with each other, and the compressor 8 and the ejector 42 communicate with each other. The communication path between the crankcase 17 and the surge tank 3 a and the communication path between the compressor 8 and the ejector 42 are partitioned by a partition 73.

  The ECU 19 controls as follows by the VSV 60 having such a configuration and action. First, when the operating range of the engine 1 is close to the supercharging range and the engine speed ne is higher than the predetermined speed (operating condition range A1), the ECU 19 causes the VSV 60 to perform the operation as shown in FIG. In addition, the compressor 8 and the ejector 42 are shut off while the crankcase 17 and the surge tank 3a are communicated.

  Further, when the engine 1 is in the supercharging region and immediately after the vehicle decelerates (operating condition region A2), the ECU 19 uses the VSV 60 to connect the crankcase 17 and the surge tank 3a as shown in FIG. While shutting off, the compressor 8 and the ejector 42 are communicated.

  As a modification, the second valve body 66 may communicate or block between the crankcase 17 and the ejector 42 instead of between the compressor 8 and the ejector 42.

  According to the blow-by gas reduction apparatus of the present embodiment as described above, the VSV 60 corresponds to a combination of the VSV 34 and the VSV 46. Thereby, since the number of parts can be reduced, cost can be reduced.

<Example 3>
Next, the third embodiment will be described. Components that are the same as those in the first and second embodiments are denoted by the same reference numerals, description thereof will be omitted, and different points will be mainly described.

  As shown in FIG. 12, the blow-by gas reduction device of the third embodiment is different from the first and second embodiments in that it does not have the VSV 46 but has a communication path 74. The communication passage 74 is provided between the surge tank 3a and the passage 40a upstream of the ejector 42 (upstream of the compressor 8) in the intake bypass passage 40. The communication path 74 is provided with a flow rate control valve 76 that controls the flow rate of the communication path 74.

  As shown in FIGS. 13 to 15, the flow control valve 76 includes a housing 78, a first valve seat 80, a second valve seat 82, a valve body 84, and a spring 86. The housing 78 is formed so that its diameter is larger than the diameter of the communication path 74. The first valve seat 80 is provided on the inner surface of the housing 78 on the intake bypass passage 40 side. The second valve seat 82 is provided on the inner surface of the housing 78 on the surge tank 3a side. The valve body 84 is provided in a state in which it can contact the first valve seat 80 and the second valve seat 82. The valve body 84 includes a flange-shaped flange portion 84a at the end portion on the first valve seat 80 side in the central axis direction, and a substantially conical cone portion at the end portion on the second valve seat 82 side. 84b. Note that the diameter of the flange portion 84 a is larger than the diameter of the communication path 74 and smaller than the diameter of the housing 78. The spring 86 urges the valve body 84 in a direction in which the valve body 84 abuts on the first valve seat 80 (a direction away from the second valve seat 82).

  As described above, the blow-by gas reduction device according to the third embodiment includes the communication path 74 and the flow control valve 76 having a simple structure instead of the VSV 46, so that the cost can be reduced.

  The blow-by gas reducing apparatus according to the third embodiment configured as described above operates as follows.

  First, when the operating range of the engine 1 is close to the supercharging range and the engine speed ne is higher than a predetermined speed (in the operating condition range B1, the operating range of “excessive flow rate” in FIG. 18). 16), the ECU 19 opens the VSV 34 as shown in FIG. At this time, the flow control valve 76 is opened. Specifically, as shown in FIG. 13, the flow rate control valve 76 has a valve body 84 that is separated from the first valve seat 80 and the second valve seat 82 by a balance between the biasing force of the spring 86 and the pressure in the passage 40 a. The valve is separated and opened. Therefore, a part of the air flowing through the passage 40a flows into the surge tank 3a through the communication passage 74. Therefore, since the amount of air flowing into the ejector 42 from the passage 40a is suppressed, the reduction flow rate of blow-by gas to the engine 1 by the second blow-by gas reduction unit 22 is suppressed.

  Also, when the engine speed ne is lower than the predetermined engine speed and the intake pipe pressure (pressure in the surge tank 3a) is between atmospheric pressure and low supercharging pressure (in the operating condition range B2), FIG. As shown in FIG. 16, the ECU 19 opens the VSV 34. At this time, the flow control valve 76 is closed. Specifically, as shown in FIG. 14, the flow rate control valve 76 is in a closed state by the flange portion 84 a of the valve body 84 abutting against the first valve seat 80 by the biasing force of the spring 86. Therefore, all the air flowing through the passage 40a flows into the ejector 42 without flowing into the surge tank 3a through the communication passage 74. Therefore, the reduction flow rate of blow-by gas to the engine 1 by the second blow-by gas reduction unit 22 is not suppressed.

  Further, when the intake pipe pressure is a high supercharging pressure or a high negative pressure (in the operating condition range B3), the ECU 19 opens the VSV 34 as shown in FIG. At this time, the flow control valve 76 is closed. Specifically, as shown in FIG. 15, a force that opposes the urging force of the spring 86 of the flow control valve 76 is applied by the pressure in the passage 40a. As a result, the flow control valve 76 is brought into a closed state with the conical portion 84b of the valve body 84 in contact with the second valve seat 82. Therefore, all the air flowing through the passage 40a flows into the ejector 42 without flowing into the surge tank 3a through the communication passage 74. Therefore, the reduction flow rate of blow-by gas to the engine 1 by the second blow-by gas reduction unit 22 is not suppressed.

  Further, when the engine 1 is in the supercharging region and immediately after the vehicle decelerates (in the driving condition region B4), the ECU 19 closes the VSV 34 as shown in FIG. At this time, the flow control valve 76 is opened.

  When the engine 1 is in an operating range (operating condition range B5) other than the above (operating condition range B1 to operating condition range B4), the ECU 19 opens the VSV 34 as shown in FIG. At this time, the flow control valve 76 is opened.

  As a modification, the blow-by gas reduction device may not have the VSV 34 as shown in FIG.

  The blow-by gas reduction device of the present embodiment includes a communication passage 74 provided between the intake bypass passage 40 and the surge tank 3a, and a flow rate control valve 76 that controls the flow rate of the communication passage 74. Thereby, the flow rate of the flow path of the blow-by gas in the second blow-by gas reduction unit 22 is controlled in accordance with the operating range of the engine 1. Therefore, the reduction flow rate of blow-by gas to the engine 1 is more appropriately adjusted according to the operating range of the engine 1.

  Further, when the operating range of the engine 1 is close to the supercharging range and the engine speed ne is higher than the predetermined speed, the flow control valve 76 is opened. Thereby, since the flow rate of the air flowing into the ejector 42 is suppressed, the reduction flow rate of the blow-by gas in the second blow-by gas reduction passage 44 is suppressed. Therefore, the reduction flow rate of blow-by gas to the engine 1 by the second blow-by gas reduction unit 22 is suppressed. Therefore, when the operating range of the engine 1 is close to the supercharging region and the engine speed ne is higher than the predetermined engine speed, the reduction flow rate of the blow-by gas to the engine 1 does not become excessive. Therefore, the blow-by gas reduction device of the present embodiment can prevent an increase in the amount of engine oil that is taken out of the crankcase 17.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention.

1 Engine 3 Intake passage 3a Surge tank 7 Supercharger 8 Compressor 9 Turbine 15 Throttle valve 16 Head cover 17 Crankcase 18 Combustion chamber 19 ECU
20 First blowby gas reduction section 22 Second blowby gas reduction section 30 First blowby gas reduction passage 32 Variable PCV valve 34 VSV
40 Intake bypass passage 40a Passage 42 (upstream of the ejector) Ejector 44 Second blow-by gas reduction passage 46 VSV
58 Fresh air introduction passage 60 VSV
64 1st valve body 66 2nd valve body 74 Communication path 76 Fluid control valve 78 Housing 80 1st valve seat 82 2nd valve seat 84 Valve body 84a Flange part 84b Conical part 86 Spring ne Engine speed kl Engine load tp PCV opening Degree ce Residual exhaust gas rate counter value CE (i) Accumulated crankcase exhaust gas amount ke PCV opening correction coefficient Tp Final target PCV opening

Claims (7)

In a blow-by gas reduction device for an engine with a supercharger that is provided in an engine having a supercharger in an intake passage, and that reduces blow-by gas generated in the engine to the engine,
A first blow-by gas reduction section having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine;
A bypass passage connected to an upstream side and a downstream side of the turbocharger in the intake passage; an ejector for generating a negative pressure in the bypass passage; and a second blow-by gas communicating with the ejector and the crankcase A second blow-by gas reduction unit comprising a reduction passage;
Possess a control unit for controlling in accordance with the reduction rate of the blow-by gas according to at least one of the first blow-by gas reducing portion or the second blow-by gas returning section to the operation region of the engine,
The second blow-by gas reduction unit includes a second switching valve that switches between communication and blocking of the bypass passage or the second blow-by gas reduction passage,
The control unit controls opening and closing of the second switching valve according to an operating range of the engine,
The control unit closes the second switching valve when the engine operating range is near a supercharging range and the engine speed is higher than a predetermined speed,
A blow-by gas reduction device for an engine with a supercharger. The blow-by gas reduction device for a supercharged engine according to claim 1 ,
The first blow-by gas reduction unit includes a first switching valve that switches between communication and blocking of the first blow-by gas reduction passage;
The control unit controls opening and closing of the first switching valve according to an operating range of the engine;
A blow-by gas reduction device for an engine with a supercharger. The blow-by gas reduction device for a supercharged engine according to claim 2 ,
The control unit closes the first switching valve when the operating range of the engine is in a supercharging range and immediately after deceleration,
A blow-by gas reduction device for an engine with a supercharger. In a blow-by gas reduction device for an engine with a supercharger that is provided in an engine having a supercharger in an intake passage, and that reduces blow-by gas generated in the engine to the engine,
A first blow-by gas reduction section having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine;
A bypass passage connected to an upstream side and a downstream side of the turbocharger in the intake passage; an ejector for generating a negative pressure in the bypass passage; and a second blow-by gas communicating with the ejector and the crankcase A second blow-by gas reduction unit comprising a reduction passage;
A control unit that controls a reduction flow rate of the blow-by gas by at least one of the first blow-by gas reduction unit or the second blow-by gas reduction unit according to an operating range of the engine,
The control unit performs control to reduce the flow rate of the blowby gas to the engine immediately after deceleration, and the amount and time to reduce the flow rate of the blowby gas according to the exhaust gas residual rate in the crankcase To establish,
A blow-by gas reduction device for an engine with a supercharger . In a blow-by gas reduction device for an engine with a supercharger that is provided in an engine having a supercharger in an intake passage, and that reduces blow-by gas generated in the engine to the engine,
A first blow-by gas reduction section having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine;
A bypass passage connected to an upstream side and a downstream side of the turbocharger in the intake passage; an ejector for generating a negative pressure in the bypass passage; and a second blow-by gas communicating with the ejector and the crankcase A second blow-by gas reduction unit comprising a reduction passage;
A control unit that controls a reduction flow rate of the blow-by gas by at least one of the first blow-by gas reduction unit or the second blow-by gas reduction unit according to an operating range of the engine,
The first blow-by gas reduction unit includes a first switching valve that switches between communication and blocking of the first blow-by gas reduction passage;
The control unit controls opening and closing of the first switching valve according to an operating range of the engine,
The second blow-by gas reduction unit includes a second switching valve that switches between communication and blocking of the bypass passage or the second blow-by gas reduction passage,
The control unit controls opening and closing of the second switching valve according to an operating range of the engine,
The first switching valve and the second switching valve are integrated;
A blow-by gas reduction device for an engine with a supercharger. In a blow-by gas reduction device for an engine with a supercharger that is provided in an engine having a supercharger in an intake passage, and that reduces blow-by gas generated in the engine to the engine,
A first blow-by gas reduction section having a first blow-by gas reduction passage communicating with a surge tank provided in the intake passage and a crankcase of the engine;
A bypass passage connected to an upstream side and a downstream side of the turbocharger in the intake passage; an ejector for generating a negative pressure in the bypass passage; and a second blow-by gas communicating with the ejector and the crankcase A second blow-by gas reduction unit comprising a reduction passage;
A control unit that controls a reduction flow rate of the blow-by gas by at least one of the first blow-by gas reduction unit or the second blow-by gas reduction unit according to an operating range of the engine,
A communication path provided between the bypass path and the surge tank;
A flow rate control valve for controlling the flow rate of the communication path,
A blow-by gas reduction device for an engine with a supercharger. The blow-by gas reduction device for a supercharged engine according to claim 6 ,
The flow control valve is in an open state when the operating range of the engine is near a supercharging range and the engine speed is higher than a predetermined speed;
A blow-by gas reduction device for an engine with a supercharger.

Images