JP2009293556A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, suppressing adhesion of deposits to a portion downstream of an intake air flow control valve caused by blowby gas when the intake air flow control valve is arranged downstream of the connection portion of a blowby gas recirculation passage in the intake passage of the internal combustion engine. <P>SOLUTION: An electronic control device 60 controls such that a tumble control valve 24 is opened to fully open the intake passage 20, provided that a flow rate of blowby gas recirculated from the blowby gas recirculation passage 26 to the intake passage 20 is a predetermined flow rate or higher. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device applied to an internal combustion engine in which an intake air flow control valve for adjusting the degree of deflection of an intake air flow is provided downstream of a connection portion of a blow-by gas recirculation passage in an intake air passage.

2. Description of the Related Art Conventionally, as described in Patent Document 1, for example, an intake flow control valve for deflecting intake flow is provided in an intake passage of an internal combustion engine so that intake air forms a tumble flow or the like in a cylinder. . In the internal combustion engine described in Patent Document 1, a blow-by gas recirculation passage for recirculating blow-by gas in the crank chamber is connected to the intake passage for ventilation of the crank chamber.
JP 2004-308472 A

  By the way, in an internal combustion engine, an intake passage in which an intake flow control valve 102 is provided on the downstream side of the connection portion of the blowby gas recirculation passage 101 in the intake passage 100 as shown in FIG. A structure may be adopted. In such a case, when the intake flow control valve 102 closes a part of the intake passage 100 to deflect the intake flow, the intake flow stagnation occurs immediately downstream of the intake flow control valve 102. Therefore, when the blowby gas is recirculated through the blowby gas recirculation passage 101 in this state, the blowby gas stays in a portion where the stagnation occurs on the downstream side of the intake flow control valve 102, and the portion on the intake downstream side of the intake flow control valve 102 In other words, deposits caused by lubricating oil or the like contained in the blowby gas may adhere.

  The present invention has been made in view of such circumstances, and its purpose is attributed to blow-by gas when an intake flow control valve is provided on the downstream side of the connection portion of the blow-by gas recirculation passage in the intake passage of the internal combustion engine. Then, it is providing the control apparatus of the internal combustion engine which can suppress that a deposit adheres to the site | part of the downstream of an intake flow control valve.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
According to the first aspect of the present invention, an intake flow control valve that deflects the intake flow by closing a part of the intake passage, a blow-by gas recirculation passage that recirculates the blow-by gas in the crank chamber to the intake passage, and the blow-by An internal combustion engine having a flow rate adjusting valve provided in a gas recirculation passage for adjusting a flow rate of the blowby gas to be recirculated, wherein the intake flow control valve is provided on a downstream side of a connection portion of the blowby gas recirculation passage in the intake passage. A control device applied to an engine, wherein the intake flow control valve fully opens the intake passage on condition that a flow rate of blow-by gas returned from the blow-by gas return passage to the intake passage is equal to or higher than a predetermined flow rate. The gist is to control to an open state.

  According to the above configuration, when the flow rate of the blow-by gas recirculated to the intake passage is equal to or higher than the predetermined flow rate, the intake flow control valve is controlled to be in the open state, and therefore immediately downstream of the intake flow control valve. Stagnation of the intake flow on the side can be suppressed. Therefore, when the flow rate of the blow-by gas returned to the intake passage is equal to or higher than a predetermined flow rate, it is possible to suppress the blow-by gas from staying downstream of the intake flow control valve. It is possible to suppress deposits due to lubricating oil or the like contained in blow-by gas on the downstream surface or the like.

  The predetermined flow rate of blow-by gas serving as a reference for opening the intake flow control valve can be set as appropriate. Specifically, for example, the intake flow control valve may be controlled to be opened on condition that a large amount of blow-by gas is recirculated to the intake passage. The intake flow control valve may be controlled to be in an open state on the condition that the air is recirculated.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the flow rate adjusting valve for adjusting the flow rate of the blow-by gas is electrically driven.
When using an electrically driven blow-by gas flow control valve, it returns to the intake passage as compared to using a mechanical flow control valve that opens according to the difference between the intake negative pressure and the crank chamber pressure. It is easy to control the flow rate of blow-by gas to be made and to easily grasp the flow rate. Therefore, according to the above configuration, it is possible to easily grasp the state where the recirculation amount of the blowby gas is equal to or higher than the predetermined flow rate, and to electrically control the flow rate adjusting valve so that the recirculation amount of the blowby gas is equal to or higher than the predetermined flow rate. At this time, it is possible to perform cooperative control of the flow rate adjustment valve and the intake flow control valve in such a manner that the intake flow control valve is controlled to be in an open state.

  According to a third aspect of the present invention, in the first or second aspect, an exhaust gas recirculation passage for recirculating a part of the exhaust gas flowing through the exhaust passage of the engine is connected to the intake air passage, and the intake flow control valve is opened. The gist of the present invention is to limit the flow rate of the exhaust gas recirculated to the intake passage through the exhaust gas recirculation passage so as to be equal to or lower than a predetermined exhaust flow rate during the execution of the control.

  When the intake flow control valve is controlled to be in the open state, the intake flow is not deflected in the intake passage, and therefore combustion cannot be promoted by the deflection of the intake flow in the combustion chamber of the internal combustion engine. Further, when the internal combustion engine includes the exhaust gas recirculation passage, the combustion state in the combustion chamber becomes slow as the flow rate of the exhaust gas recirculated to the intake passage through the exhaust gas recirculation passage increases. In this regard, according to the above configuration, when the combustion is not promoted due to the deflection of the intake flow, the flow rate of the exhaust gas recirculated to the intake passage is limited, so that the combustion state in the combustion chamber is deteriorated. Can be suppressed.

The invention according to claim 4 is characterized in that the exhaust gas recirculation passage is connected to the downstream side of the intake flow control valve in the intake passage.
According to said structure, it can suppress that the situation where a deposit adheres to an intake flow control valve resulting from the exhaust_gas | exhaustion returned to an intake passage through an exhaust gas recirculation passage can be suppressed.

  In particular, in the case of adopting a control mode in which the opening / closing control of the intake flow control valve is performed based on the exhaust gas recirculation amount, the intake passage control valve is used to suppress the deterioration of combustion when the exhaust gas recirculation amount is increased. May cause obstruction. Therefore, when such a control mode is adopted, if the exhaust gas recirculation passage is connected to the upstream side of the intake air flow control valve in the intake air passage, the intake air flow control valve closes the intake air passage so that the intake air flow control valve Since a large amount of exhaust gas is recirculated when intake air stagnation occurs on the downstream side, deposits caused by the exhaust gas easily adhere to the downstream side of the intake flow control valve. In this regard, according to the above-described configuration, it is possible to appropriately suppress deposit adhesion of the intake flow control valve due to such exhaust.

Hereinafter, an embodiment of a control device for an internal combustion engine according to the present invention will be described with reference to FIGS.
FIG. 1 shows an internal combustion engine to which the control device is applied and its peripheral mechanism. As shown in FIG. 1, the internal combustion engine 10 of the present embodiment is a vehicular in-cylinder gasoline engine, and includes a combustion chamber 12 formed in each cylinder 11 and an intake passage 20 that feeds intake air into the combustion chamber 12. And an exhaust passage 23 through which exhaust gas generated by combustion in the combustion chamber 12 is discharged.

The combustion chamber 12 is provided with an injector 14 that directly injects fuel and a spark plug 16 that ignites a mixture of fuel and air injected by the injector 14.
A throttle valve 21 is provided in the intake passage 20, and the throttle valve 21 is opened and closed by a throttle motor 22, thereby adjusting the flow rate of the intake air supplied to the combustion chamber 12 through the intake passage 20.

  A surge tank 29 is provided downstream of the throttle valve 21 in the intake passage 20, and a tumble control valve 24 is provided as an intake flow control valve for controlling the degree of deflection of the intake flow further downstream thereof. . The tumble control valve 24 is a cantilever valve in which an end portion on the upstream side of a plate-like valve body 24a is pivotally supported with respect to the intake passage 20 by a rotation shaft 24b. The tumble control valve 24 is driven to open and close by an actuator 25, and the valve body 24a is in a closed state in which a part of the intake passage 20 is closed as indicated by a two-dot chain line, thereby deflecting the intake flow and taking in the intake air in the cylinder 11. Is forming a tumble flow.

  An intake passage 34 for introducing air into the crank chamber 40 from the intake upstream side of the throttle valve 21 is connected to the intake passage 20, and a blow-by gas in the crank chamber 40 is connected to the surge tank 29 of the intake passage 20. Is connected to a blow-by gas recirculation passage 26. The blow-by gas recirculation passage 26 is provided with a PCV valve 27 for adjusting the flow rate of the blow-by gas flowing through the blow-by gas recirculation passage 26 as a flow adjustment valve. The PCV valve 27 is an electronically controlled valve whose opening degree can be freely adjusted. Specifically, a drive signal from an electronic control device 60 to be described later is output to an actuator 28 of the PCV valve 27 so that the valve 27 can be adjusted. Is adjusted.

  An exhaust gas recirculation passage (hereinafter referred to as “EGR passage”) 30 for introducing a part of the exhaust gas flowing through the exhaust passage 23 into the intake passage 20 is connected to the downstream side of the portion where the tumble control valve 24 is provided in the intake passage 20. Has been. The EGR passage 30 is provided with a flow rate control valve (hereinafter referred to as “EGR valve”) 31 for adjusting the flow rate of the exhaust gas flowing through the EGR passage 30. The EGR valve 31 is driven by an actuator 32. The

  Various controls of the internal combustion engine 10 are performed by an electronic control device 60 mounted on the vehicle. The electronic control unit 60 includes a CPU that executes arithmetic processing related to the control of the internal combustion engine 10, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores arithmetic results of the CPU, An input / output port for inputting / outputting a signal between them is provided.

  Detection signals from various sensors that detect the operating state of the internal combustion engine 10 are input to the input port of the electronic control unit 60. Specifically, the internal combustion engine 10 is provided with an accelerator sensor 52 that detects the amount of depression of the accelerator pedal 44 by the driver. A throttle sensor 53 that detects the opening degree is provided in the vicinity of the throttle valve 21. Further, although not shown in the internal combustion engine 10, an air flow meter provided in the intake passage 20 for detecting the intake air amount, an intake air temperature sensor for detecting the intake air temperature, and an engine rotational speed NE provided in the vicinity of the crankshaft are detected. A rotation speed sensor, a water temperature sensor that is attached to the cylinder block and detects the engine cooling water temperature, and the like are provided. Then, the detection signals of these various sensors are input to the input port of the electronic control device 60.

  The output port of the electronic control unit 60 is connected to drive circuits such as the injectors 14, the actuators 22, 25, 28, and 32 that drive the various valves 21, 24, 27, and 31. The electronic control unit 60 grasps the operating state of the internal combustion engine 10 based on the detection signals input from the various sensors, and outputs command signals to various driving circuits connected to the output port according to the grasped operating state. To do. Thus, control of the fuel injection amount by the injector 14, control of the opening degree of the throttle valve 21, control of the flow rate of exhaust gas recirculated to the intake passage 20 through the EGR passage 30, and control of the blowby gas recirculated to the intake passage 20 through the blowby gas recirculation passage 26 Flow rate control, opening / closing control of the tumble control valve 24, and the like are performed.

  Specifically, the electronic control unit 60 controls the opening degree of the throttle valve 21 to adjust the intake air amount based on the depression amount of the accelerator pedal 44 detected by the accelerator sensor 52, and based on the intake air amount. Thus, the fuel injection amount injected by the injector 14 is adjusted.

  Further, the electronic control unit 60, for example, exhausts recirculated to the intake passage 20 to improve fuel consumption when it is determined that the internal combustion engine 10 is in a low load to medium load operation state based on detection results of various sensors. The opening degree of the EGR valve 31 is increased so as to increase the flow rate. At this time, the electronic control unit 60 controls the tumble control valve 24 to be in a closed state indicated by a two-dot chain line in FIG. That is, if the exhaust gas recirculation amount is increased, the amount of exhaust gas in the air supplied into the cylinder 11 increases, so that the combustion speed may become excessively slow and the combustion state may be deteriorated. The valve 24 promotes the turbulence of the airflow in the cylinder 11 to improve the combustion state. Thus, in this embodiment, when the opening degree of the EGR valve 31 is controlled so that the flow rate of the exhaust gas introduced into the intake passage 20 is increased, the tumble control valve 24 is controlled to be closed. In this embodiment, the electronic control device 60 performs coordinated control of the EGR valve 31 and the tumble control valve 24.

  Furthermore, the electronic control unit 60 adjusts the opening degree of the PCV valve 27 according to the operating state. Specifically, for example, when it is assumed that the blow-by gas in the crank chamber 40 has accumulated to some extent (for example, every predetermined period), the electronic control unit 60 opens the PCV valve 27 fully and generates a large amount of blow-by gas. Mass scavenging control for returning to the intake passage 20 is executed.

  By the way, in this embodiment, the blow-by gas recirculation passage 26 is connected to the upstream side of the tumble control valve 24 in the intake passage 20. Therefore, when the tumble control valve 24 is in a state of blocking a part of the intake passage 20 to deflect the intake flow, the stagnation of the intake flow occurs immediately downstream of the tumble control valve 24. Therefore, when the blowby gas is recirculated through the blowby gas recirculation passage 26 in this state, the blowby gas stays in a portion where the stagnation occurs on the downstream side of the tumble control valve 24, and the valve body 24a of the tumble control valve 24 and the rotating shaft are retained. When the valve 24 is closed in 24b, a situation occurs in which deposits due to the lubricating oil or the like contained in the blow-by gas adhere to a portion on the intake downstream side. In particular, in this embodiment, mass scavenging control of blow-by gas is executed. Therefore, if the tumble control valve 24 is closed during execution of this mass scavenging control, deposit adhesion of the tumble control valve 24 becomes significant.

  In the present embodiment, a tumble control valve 24 is provided on the upstream side of the connection portion of the EGR passage 30 in the intake passage 20. Therefore, even when the tumble control valve 24 is closed and stagnation occurs on the intake downstream side of the valve 24, the tumble control valve 24 to the tumble control valve 24 caused by the exhaust gas recirculated to the intake passage 20 through the EGR passage 30 can be obtained. Deposit adhesion is hardly a problem.

  Therefore, in the present embodiment, the electronic control device 60 serves as a control device for the internal combustion engine 10 to suppress deposits caused by blow-by gas from adhering to the tumble control valve 24 (hereinafter referred to as “deposit adhesion suppression control”). To do. Hereinafter, deposit adhesion suppression control executed by the electronic control unit 60 will be described based on the flowchart of FIG. 2 and the timing chart of FIG. A series of processing shown in the flowchart of FIG. 2 is performed, for example, at predetermined intervals during the operation of the internal combustion engine 10.

  As shown in FIG. 2, when the deposit adhesion suppression control of the tumble control valve 24 is started, it is determined in step S11 whether or not the flow rate of the blow-by gas returned to the intake passage 20 is equal to or higher than a predetermined flow rate. Is called. Specifically, it is determined whether or not the actuator 28 is controlling the opening of the PCV valve 27 to be equal to or greater than a predetermined opening α corresponding to a predetermined flow rate. In the present embodiment, the predetermined flow rate of the blow-by gas is set to a somewhat large amount.

  In step S11, when it is determined that the opening degree of the PCV valve 27 is less than the predetermined opening degree α and the flow rate of the blow-by gas recirculated to the intake passage 20 is less than the predetermined flow rate, the process proceeds to the end and the process is temporarily ended. Is done. That is, if the recirculation amount of the blow-by gas is less than the predetermined flow rate, even if the tumble control valve 24 is closed and stagnation occurs immediately downstream of the valve 24, the downstream side of the tumble control valve 24 immediately downstream. It is determined that the amount of blow-by gas staying in the chamber is small and deposit adhesion to the valve 24 is not so much of a problem, and this processing is terminated. On the other hand, when the opening degree of the PCV valve 27 is controlled to be equal to or greater than the predetermined opening α, such as when performing a large amount of blow-by gas scavenging control, the flow rate of the blow-by gas returned to the intake passage 20 is equal to or higher than the predetermined flow rate. And the process proceeds to step S12.

  In step S12, the tumble control valve 24 is controlled to be opened. Specifically, the valve body 24a of the tumble control valve 24 is in the state shown by the solid line in FIG. As a result, the stagnation of the intake flow is suppressed immediately downstream of the tumble control valve 24. Therefore, it is possible to suppress the blowby gas exceeding the predetermined flow rate from staying on the downstream side of the tumble control valve 24. Although the flow rate of the blowby gas is large, the tumble control valve 24 can be used as a lubricant contained in the blowby gas. It is suppressed that the deposit which originated adheres.

  Then, the process proceeds from step S12 to step S13, and the flow rate of the exhaust gas recirculated to the intake passage 20 through the EGR passage 30 is controlled to be equal to or lower than a predetermined exhaust gas flow rate. Specifically, the opening degree of the EGR valve 31 is controlled to be equal to or less than a predetermined opening degree β. That is, in step S12, since the tumble control valve 24 is controlled to be in the open state, the combustion cannot be expected to be accelerated by the deflection of the intake air flow in the combustion chamber 12 by the tumble control valve 24. Therefore, when the amount of exhaust gas recirculated to the intake passage 20 through the EGR passage 30 when the tumble control valve 24 is controlled to be in the open state in this way, the combustion state in the combustion chamber 12 may be deteriorated. Therefore, in step S13, the exhaust gas recirculation amount is limited to a predetermined exhaust gas flow rate or less, thereby suppressing deterioration of the combustion state in the combustion chamber 12 and stabilizing the combustion state.

  As described above, when the opening degree of the PCV valve 27 is equal to or larger than the predetermined opening degree α, the opening degree of the tumble control valve 24 and the EGR valve 31 is also cooperatively controlled. Then, the process proceeds from step S13 to END, and this process is terminated.

  The above control will be described with reference to the timing chart of FIG. Prior to time t1, since the opening degree of the PCV valve 27 is equal to or less than the predetermined opening degree α, the deposit adhesion suppression control of the tumble control valve 24 caused by blow-by gas is not performed. Accordingly, at this time, the tumble control valve 24 is closed when the opening degree of the EGR valve 31 is large, and the tumble control valve 24 is opened when the opening degree of the EGR valve 31 is not so large. The opening degree of the EGR valve 31 is controlled.

  After time t1, for example, when the blow-by gas mass scavenging control is executed and the opening degree of the PCV valve 27 becomes equal to or larger than the predetermined opening angle α, the flow rate of the blow-by gas recirculated to the intake passage 20 is equal to or higher than the predetermined flow rate. As a result, the tumble control valve 24 is opened, and deposit adhesion to the valve 24 due to blow-by gas is suppressed. Further, after the time t1, the opening degree of the EGR valve 31 is also controlled to be equal to or less than the predetermined opening degree β, and in a situation where combustion cannot be promoted due to the deflection of the intake air flow in the combustion chamber 12, a large amount of exhaust gas is in the combustion chamber 12. The introduction is suppressed, and deterioration of the combustion state in the combustion chamber 12 is suppressed.

According to this embodiment explained in full detail above, the following effects can be obtained.
(1) In the present embodiment, a tumble control valve 24 is provided in the intake passage 20 of the internal combustion engine 10 on the downstream side of the connection part of the blow-by gas recirculation passage 26. The electronic control unit 60 is in an open state in which the tumble control valve 24 fully opens the intake passage 20 on condition that the flow rate of the blowby gas returned from the blowby gas return passage 26 to the intake passage 20 is equal to or higher than a predetermined flow rate. It controls to become. As a result, when the amount of blow-by gas recirculated to the intake passage 20 exceeds a predetermined flow rate, the tumble control valve 24 is controlled to be in an open state, so that the intake air is immediately downstream of the tumble control valve 24. Stagnation of the flow can be suppressed. Therefore, when the flow rate of the blow-by gas recirculated to the intake passage 20 is equal to or higher than a predetermined flow rate, it is possible to prevent the blow-by gas from staying on the downstream side of the tumble control valve 24 and It is possible to suppress deposits due to the contained lubricating oil or the like.

  (2) In this embodiment, an electronically controlled valve is used as the PCV valve 27 for adjusting the flow rate of blow-by gas. Therefore, in determining whether or not the recirculation amount of the blowby gas is equal to or greater than a predetermined flow rate, whether the drive signal to the actuator 28 by the electronic control device 60 sets the PCV valve 27 to be equal to or greater than the predetermined opening α. This can be done by determining this. That is, since the electrically driven PCV valve 27 is used in the present embodiment, the flow rate of the blow-by gas recirculated to the intake passage 20 can be easily adjusted as compared with the case where a mechanical PCV valve is used. The recirculation amount of blow-by gas can be easily grasped. Accordingly, the PCV valve 27 is controlled in such a manner that the tumble control valve 24 is opened when the drive signal to the actuator 28 by the electronic control device 60 sets the PCV valve 27 to a predetermined opening α or more. Coordinated control with the tumble control valve 24 can be easily performed.

  (3) In the present embodiment, the EGR passage 30 that recirculates a part of the exhaust gas flowing through the exhaust passage 23 is connected to the intake passage 20, and the control is performed through the EGR passage 30 during execution of the control for opening the tumble control valve 24. The flow rate of the exhaust gas recirculated to the intake passage 20 is limited to be equal to or lower than a predetermined exhaust gas flow rate. As a result, in a state where the tumble control valve 24 is opened and combustion acceleration in the combustion chamber 12 due to deflection of the intake air flow cannot be expected, it is possible to suppress a large amount of exhaust gas from being recirculated. It can suppress that a combustion state deteriorates.

  (4) In the present embodiment, the EGR passage 30 is connected to the downstream side of the tumble control valve 24 in the intake passage 20. Thereby, it is possible to suppress the occurrence of a situation in which deposits adhere to the tumble control valve 24 due to the exhaust gas recirculated to the intake passage 20 through the EGR passage 30.

  In particular, the present embodiment employs a control mode in which the opening / closing control of the tumble control valve 24 is performed based on the exhaust gas recirculation amount, and the tumble control valve 24 is closed to promote combustion when the exhaust gas recirculation amount is increased. It is controlled so that. Therefore, when the tumble control valve 24 is closed and intake air stagnation occurs downstream of the tumble control valve 24, a large amount of exhaust gas is recirculated. However, in this embodiment, since the EGR passage 30 is connected to the downstream side of the tumble control valve 24 in the intake passage 20, even if such stagnation occurs, the exhaust gas stays immediately downstream of the tumble control valve 24. A situation cannot occur, and deposit adhesion of the tumble control valve 24 due to exhaust can be suppressed.

(Other embodiments)
In addition, you may change the said embodiment suitably as follows.
In each of the above embodiments, the EGR passage 30 is connected to the downstream side of the tumble control valve 24 in the intake passage 20, but the EGR passage is connected to the upstream side of the tumble control valve 24 in the intake passage. Also good. Since the exhaust gas recirculated to the intake passage through the EGR passage does not contain as much lubricating oil as the blow-by gas, even if the exhaust stays immediately downstream of the tumble control valve, the exhaust gas stays in the exhaust. Deposit adhesion is not a problem.

  In each of the above embodiments, the internal combustion engine 10 includes the EGR passage 30, but the internal combustion engine may not include the EGR passage. Further, even when the internal combustion engine includes EGR, the EGR valve 31 and the tumble control valve 24 are individually provided without performing the cooperative control of the EGR valve 31 and the tumble control valve 24 as in the above embodiments. It may be controlled.

  In each of the above embodiments, the PCV valve 27 that is electrically driven is used. However, a mechanical PCV valve may be provided in the blow-by gas recirculation passage. In that case, the flow rate of the blowby gas recirculated to the intake passage 20 may be estimated from, for example, the degree of this negative pressure by detecting the negative pressure in the intake passage, or may be estimated based on the engine operating state. Alternatively, it may be derived by actually detecting the recirculation amount of the blow-by gas and the opening degree of the PCV valve. In this case, the opening / closing control of the tumble control valve is performed by determining whether or not the recirculation amount of the blow-by gas thus derived is equal to or greater than a predetermined flow rate.

  In each of the above embodiments, the predetermined flow rate of the blow-by gas serving as a reference for opening the tumble control valve 24 is set to a relatively high flow rate. However, for example, when the blow-by gas is returned to the intake passage, the amount is small. Even if it exists, you may make it control so that the tumble control valve 24 may be in an open state. That is, the tumble control valve 24 may be controlled to be in an open state on condition that the recirculation amount of the blowby gas is not “0”.

  In each of the above embodiments, the intake flow control valve is the tumble control valve 24. However, the intake flow control valve only needs to deflect the intake flow by closing a part of the intake passage, and may not form a tumble flow of intake air in the combustion chamber. In particular, in the case of a cantilever valve, stagnation is likely to occur immediately downstream of the valve as described above, and deposits due to blow-by gas are likely to adhere to this part. You may make it apply the control apparatus of this invention to a valve | bulb.

  In each of the above embodiments, the internal combustion engine to which the control device according to the present invention is applied is a direct-injection gasoline engine, but may be applied to a port-injection gasoline engine or a diesel engine. Good.

1 is a schematic diagram showing an internal combustion engine to which the control device is applied and its peripheral mechanism in an embodiment of a control device for an internal combustion engine according to the present invention. The flowchart which shows the execution procedure of the deposit suppression control of a tumble control valve in the same embodiment. In the embodiment, (a) is the opening degree of the PCV valve, (b) is the opening degree of the tumble control valve, and (c) is a timing chart showing the transition of the opening degree of the EGR valve. The schematic diagram which shows the structure of the intake passage of the conventional internal combustion engine.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Cylinder, 12 ... Combustion chamber, 14 ... Injector, 16 ... Spark plug, 20,100 ... Intake passage, 21 ... Throttle valve, 22 ... Throttle motor, 23 ... Exhaust passage, 24 ... Tumble control valve 24a ... valve body, 24b ... rotating shaft, 25 ... actuator, 26, 101 ... blow-by gas recirculation passage, 27 ... PCV valve, 28 ... actuator, 29 ... surge tank, 30 ... EGR passage (exhaust recirculation passage), 31 ... EGR valve (flow control valve), 32 ... actuator, 34 ... introduction passage, 40 ... crank chamber, 44 ... accelerator pedal, 52 ... accelerator sensor, 53 ... throttle sensor, 60 ... electronic control device, 102 ... intake flow control valve .

Claims (4)

An intake flow control valve that deflects the intake flow by closing a part of the intake passage, a blow-by gas recirculation passage that recirculates the blow-by gas in the crank chamber to the intake passage, and the recirculation provided in the blow-by gas recirculation passage A control device applied to an internal combustion engine having a flow rate adjusting valve for adjusting a flow rate of blowby gas to be provided, and wherein the intake flow control valve is provided on a downstream side of a connection portion of the blowby gas recirculation passage in the intake passage. And
The intake flow control valve is controlled to be in an open state in which the intake passage is fully opened, on condition that the flow rate of blow-by gas returned from the blow-by gas return passage to the intake passage is equal to or higher than a predetermined flow rate. A control device for an internal combustion engine characterized by the above. In claim 1,
The control apparatus for an internal combustion engine, wherein the flow rate adjusting valve for adjusting the flow rate of the blowby gas is electrically driven. In claim 1 or 2,
An exhaust gas recirculation passage for recirculating part of the exhaust gas flowing through the exhaust passage of the engine is connected to the intake air passage,
An internal combustion engine characterized by limiting the flow rate of exhaust gas recirculated to the intake passage through the exhaust gas recirculation passage during execution of control for opening the intake flow control valve to be a predetermined exhaust flow rate or less. Control device. In claim 3,
The control apparatus for an internal combustion engine, wherein the exhaust gas recirculation passage is connected to a downstream side of the intake flow control valve in the intake passage.

Images