JP2010203326A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine capable of appropriately removing deposits adhering to a cylinder injection injector in the internal combustion engine including the cylinder injection injector and a port injection injector. <P>SOLUTION: In a vehicle control system 1, when fuel is injected from only the port injector 26 for a predetermined period, by a first fuel injection means, a second fuel injection means, a separative injection ratio control means, a vaporized fuel introduction means, an air-fuel ratio feedback control means, a fuel injection control means, and an introduction amount restriction means, the cylinder injector 25 is cleaned, and the amount of vaporized fuel introduced into an intake passage 14 during cleaning is restricted. Thereby, it is possible to appropriately perform fuel injection for cleaning by the cylinder injector 25. Accordingly, it is possible to appropriately remove the deposits adhering to the cylinder injector 25. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine.

  An internal combustion engine comprising an in-cylinder injector capable of realizing stratified combustion by injecting fuel into a combustion chamber, and a port injector capable of realizing homogeneous combustion by injecting fuel into an intake passage or an intake port Is widely known. Such an internal combustion engine appropriately controls the ratio of the fuel injection amount from the in-cylinder injector and the fuel injection amount from the port injector according to the engine operating state, so that the engine can be operated in a wide operating range. High output and low fuel consumption can be achieved.

The in-cylinder injector is always exposed to high-temperature combustion gas because its tip is exposed in the combustion chamber. Therefore, unburned components contained in the combustion gas may become deposits and adhere to the injection hole portion of the in-cylinder injector or the vicinity thereof. If such deposit adhesion occurs, the fuel spray shape changes or the fuel injection amount decreases, which may lead to deterioration in combustibility and misfire of the internal combustion engine.
In particular, in the operation region where fuel is injected only from the port injector, deposit adhesion further proceeds to the injection hole portion of the in-cylinder injector and the vicinity thereof. Therefore, when fuel injection from only the port injector is performed for a certain period of time, cleaning control is widely performed to remove deposits attached to the injection hole portion by the injection force by injecting fuel from the in-cylinder injector. Has been.

  As a control means of such an internal combustion engine, a condition for avoiding fuel injection by only the port fuel injection mechanism is set corresponding to the fuel component related to the degree of adhesion of the in-cylinder deposits of the in-cylinder fuel injection mechanism, If the avoidance condition is satisfied when the fuel is being injected only by the fuel injection mechanism, the two types of fuel injection mechanisms are controlled so that the fuel is injected by the in-cylinder fuel injection mechanism. A technique for avoiding deposit accumulation is disclosed in Patent Document 1.

  Further, the cumulative value of the deposit accumulated at the injection port of the in-cylinder fuel injection unit is calculated in consideration of the NOx concentration, and the fuel injection of the in-cylinder fuel injection unit is controlled based on the calculation result, so that the in-cylinder fuel injection unit Patent Document 2 discloses a technique for removing deposits adhering to the film.

  Then, during fuel injection using the in-cylinder injection valve, if deposit adhesion is detected in the injection hole of the in-cylinder injection valve based on a detection signal from the air flow meter, the injection mode is switched from in-cylinder injection to port injection and the temperature is increased. Japanese Patent Application Laid-Open No. H10-228688 discloses a technique for promoting the burning of deposits adhering to the injection holes by executing the above.

On the other hand, in order to effectively burn the vaporized fuel generated in the fuel tank of the internal combustion engine, the vaporized fuel generated in the fuel tank is temporarily stored in a collection device such as a canister, and the internal combustion engine is operated according to the operating state of the internal combustion engine. Control for purging vaporized fuel in the collection device and introducing it into the intake passage is widely performed.
When the purge process is executed, the vaporized fuel from the fuel tank is introduced into the combustion chamber in addition to the injected fuel from the injector, so that the air-fuel ratio of the internal combustion engine fluctuates. In this case, the engine ECU (Electronic Control Unit) includes an air-fuel ratio (hereinafter abbreviated as (A / F)) sensor and an oxygen concentration (hereinafter abbreviated as (O2)) provided upstream and downstream of the purification catalyst. Based on the detection result of the sensor, a change in the air-fuel ratio is recognized, and feedback (hereinafter abbreviated as (F / B)) control for correcting the fuel injection amount so as to bring the changed air-fuel ratio closer to the target air-fuel ratio is executed.

  As a control means for such an internal combustion engine, an F / B correction coefficient that is set based on a detection value of an A / F sensor when the amount of evaporated fuel introduced into the intake system by purging exceeds a predetermined value is used. Patent Document 4 discloses a technique for correcting the air-fuel ratio to an appropriate value by correcting to a relatively rich side.

  An internal combustion engine having an in-cylinder injector and a port injector, wherein the purge process and the fuel injection mode of the injector are selected based on the fuel amount required by the internal combustion engine and the learned value of the vaporized fuel concentration in the purge gas. Thus, Patent Document 5 discloses a technique for efficiently using fuel and suppressing deterioration of emissions.

JP 2008-095525A JP 2006-057538 A JP 2005-201113 A JP 2004-011612 A JP 2007-198287 A

In such an internal combustion engine, when the purge process control overlaps during the cleaning control of the in-cylinder injector, high-concentration vaporized fuel is introduced into the intake passage, so that the F / B control causes the injecting from the in-cylinder injector. The fuel injection amount is corrected in the decreasing direction. In this case, when a large amount of vaporized fuel is introduced into the intake passage by the purge process, the fuel injection amount from the in-cylinder injector is greatly decreased and corrected by the F / B control, and in some cases, less than the minimum fuel injection amount There is. Then, since the cleaning control of the in-cylinder injector cannot be appropriately executed, there is a problem that deposits accumulated in the injection hole portion may not be removed.
However, in the prior art and the techniques of Patent Documents 1 to 4, there is no means for appropriately executing the cleaning control when the purge process control overlaps during the cleaning control of the in-cylinder injector. Therefore, there is a problem that the deposit accumulated in the injection hole portion of the in-cylinder injector cannot be properly removed, and the combustibility may be deteriorated or the internal combustion engine may be misfired.
Further, in the technique of Patent Document 5, the purge process control is executed when the fuel injection from only the port injector is performed for a certain period of time and the cleaning control of the in-cylinder injector is executed. There may be priority. Therefore, there is a problem that cleaning control of the in-cylinder injector may not be properly executed.

  The present invention has been made in view of such a point, and in an internal combustion engine including an in-cylinder injector and a port injection injector, the control of the internal combustion engine capable of appropriately removing deposits in the in-cylinder injector. An object is to provide an apparatus.

  In order to achieve the above object, a control apparatus for an internal combustion engine according to the present invention includes a first fuel injection means for injecting and supplying fuel to a combustion chamber of the internal combustion engine, and a second fuel for injecting and supplying fuel to an intake passage of the internal combustion engine. Based on the fuel injection means and the operating state of the internal combustion engine, an injection division for controlling the injection ratio between the fuel amount injected and supplied by the first fuel injection means and the fuel amount supplied and supplied by the second fuel injection means Ratio control means, vaporized fuel introducing means for introducing vaporized fuel in the fuel supply source of the internal combustion engine into the intake passage, and air-fuel ratio feedback control for correcting the air-fuel ratio to the target air-fuel ratio according to the operating state of the internal combustion engine A control device for an internal combustion engine comprising: means for controlling the injection dividing control means to cause only the second fuel injection means to inject fuel exceeding a first threshold value; A fuel injection control unit that injects fuel into the fuel injection unit for a predetermined time; and an introduction amount limiting unit that limits an introduction amount by the vaporized fuel introduction unit while the fuel injection control unit is executed. And

  In particular, in the control apparatus for an internal combustion engine according to the present invention, the introduction amount restriction means restricts the introduction amount by the vaporized fuel introduction means based on an air-fuel ratio correction amount executed by the air-fuel ratio feedback control means. Can be a feature.

  According to the control apparatus for an internal combustion engine of the present invention, when fuel injection from only the port injector is performed for a predetermined period, fuel injection control is performed to inject fuel into the in-cylinder injector for a predetermined time, The amount of vaporized fuel introduced into the intake passage can be limited. Accordingly, since the in-cylinder injector can appropriately perform fuel injection for cleaning, in the internal combustion engine including the in-cylinder injector and the port injector, the deposit of the in-cylinder injector can be appropriately removed. Can do.

It is the block diagram which showed schematic structure of the vehicle control system of an Example. It is the block diagram which showed schematic structure of the combustion chamber vicinity. An example of in-cylinder injector cleaning control is shown. The flow of control which ECU of an example performs is shown. The flow of control which ECU of an example performs is shown.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for implementing the present invention will be described in detail with reference to the drawings.

  Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a schematic configuration of a vehicle control system 1 incorporating a control device for an internal combustion engine of the present invention. FIG. 1 shows only the configuration of one cylinder of the engine.

  A vehicle control system 1 shown in FIG. 1 includes an engine 100 that is a power source, and includes an engine ECU 10 that comprehensively controls the driving operation of the engine 100. Further, the vehicle control system 1 includes an in-cylinder injector 25 and a port injector 26 in the combustion chamber 11a and the intake port 13, respectively. The vehicle control system 1 includes a vapor passage 41 for introducing vaporized fuel from the combustion tank into the intake passage, a canister 42, a purge passage 43, and a purge control valve 44 for controlling the flow rate of vaporized fuel passing through the purge passage 43. I have.

  The engine 100 is a multi-cylinder engine mounted on a vehicle, and each cylinder includes a piston 11 constituting a combustion chamber 11a. The piston 11 of each combustion chamber is connected to the shaft of the crankshaft 12 that is an output shaft via a connecting rod, and the reciprocating motion of the piston 11 is converted into rotation of the crankshaft 12 by the connecting rod. The piston 11 has a concave cavity formed on the top surface. The fuel injected by the in-cylinder injector 25 enters the cavity of the piston 11 and is guided to the vicinity of the spark plug 27 along the shape of the cavity (see FIG. 2).

  A crank angle sensor 31 is provided near the axis of the crankshaft 12. The crank angle sensor 31 is configured to detect the rotation angle of the crankshaft 12 axis, and transmits the detection result to the engine ECU 10. Thereby, engine ECU10 acquires the information regarding a crank angle, such as the engine speed at the time of a driving | operation, and rotation angular velocity.

  Connected to the combustion chamber 11a of each cylinder are an intake port 13 communicating with the combustion chamber 11a and an intake passage 14 connected to the intake port 13 and leading intake air from the intake port 13 to the combustion chamber 11a. . Further, each cylinder of the combustion chamber 11a is connected to an exhaust port 15 communicating with the combustion chamber 11a and an exhaust passage 16 for guiding the exhaust gas generated in the combustion chamber 11a to the outside of the engine. Further, the exhaust passages 16 connected to the respective cylinders merge on the downstream side to form one merged exhaust passage 17.

  A plurality of intake valves and exhaust valves are provided corresponding to the intake passage and the exhaust passage of the combustion chamber 11a of each cylinder. FIG. 1 shows one intake passage, one exhaust passage, one intake valve, and one exhaust valve. An intake valve 18 is arranged in each intake port 13 of the combustion chamber 11a, and an intake camshaft 20 for opening and closing the intake valve 18 is arranged. Further, an exhaust valve 19 is disposed at each exhaust port 15 of the combustion chamber 11a, and an exhaust camshaft 21 for opening and closing the exhaust valve 19 is disposed.

  The intake valve 18 and the exhaust valve 19 are opened and closed by the rotation of the intake camshaft 20 and the exhaust camshaft 21 to which the rotation of the crankshaft 12 is transmitted by a coupling mechanism (for example, a timing belt, a timing chain, etc.). 15 and the combustion chamber 11a are communicated and blocked. The phases of the intake valve 18 and the exhaust valve 19 are expressed with reference to the crank angle.

  The intake camshaft 20 has an electric VVT mechanism 22 that is a variable valve mechanism (hereinafter referred to as a VVT mechanism). The electric VVT mechanism 22 rotates the intake camshaft 20 with an electric motor in response to an instruction from the engine ECU 10. As a result, the rotational phase of the intake camshaft 20 relative to the crankshaft 12 is changed, so that the valve timing of the intake valve 18 is changed. In this case, the rotation phase of intake camshaft 20 is detected by intake cam angle sensor 32 and output to engine ECU 10. Thereby, the engine ECU 10 can acquire the phase of the intake camshaft 20 and the phase of the intake valve 18. Further, the phase of the intake camshaft 20 is expressed with reference to the crank angle.

  The exhaust camshaft 21 has a hydraulic VVT mechanism 23. The hydraulic VVT mechanism 23 rotates the exhaust camshaft 21 with an oil control valve (hereinafter referred to as OCV) according to an instruction from the engine ECU 10. As a result, the rotational phase of the exhaust camshaft 21 relative to the crankshaft 12 is changed, so that the valve timing of the exhaust valve 19 is changed. In this case, the rotational phase of the exhaust camshaft 21 is detected by the exhaust cam angle sensor 33 and output to the engine ECU 10. Accordingly, the engine ECU 10 can acquire the phase of the exhaust camshaft 21 and can acquire the phase of the exhaust valve 19. Further, the phase of the exhaust camshaft 21 is expressed with reference to the crank angle.

An air flow meter 34, a throttle valve 24, and a throttle position sensor 35 are installed in the intake passage 14 of the engine 100. The air flow meter 34 and the throttle position sensor 35 detect the amount of intake air passing through the intake passage 14 and the opening of the throttle valve 24, respectively, and transmit the detection results to the engine ECU 10. The engine ECU 10 recognizes the amount of intake air introduced into the intake port 13 and the combustion chamber 11a based on the transmitted detection result, and adjusts the opening of the throttle valve 24 to thereby adjust the intake air necessary for the operation of the engine 100. The quantity can be taken into the combustion chamber 11a.
The throttle valve 24 preferably employs a throttle-by-wire system using a step motor. For example, the opening of the throttle valve 24 is changed in conjunction with an accelerator pedal (not shown) via a wire instead of a step motor. A mechanical throttle mechanism as described above can also be applied.

  An in-cylinder injector 25 and a port injector 26 are attached to the combustion chamber 11 a and the intake port 13. High-pressure fuel supplied from a fuel pump (not shown) through a fuel pipe is injected and supplied to the combustion chamber 11a and the intake port 13 in the engine cylinder by an in-cylinder injector 25 and a port injector 26 according to instructions from the engine ECU 10. The engine ECU 10 determines the fuel injection amount and the injection timing based on the intake air amount from the air flow meter 34 and the throttle position sensor 35, and the cam shaft rotation phase information from the intake cam angle sensor 32, and determines the in-cylinder injector 25, port A signal is sent to the injector 26. In-cylinder injector 25 and port injector 26 inject high-pressure fuel into combustion chamber 11a and intake port 13 at the instructed fuel injection amount / injection timing in accordance with a signal from engine ECU 10. The leaked fuel from the in-cylinder injector 25 and the port injector 26 is returned to a fuel tank (not shown) through a relief pipe. In this case, a high pressure fuel may be supplied to the in-cylinder injector 25 by providing a pressure accumulating chamber between the fuel pump and the in-cylinder injector 25. Further, the pressure of the fuel supplied to the in-cylinder injector 25 may be increased by providing a high-pressure fuel pump between the fuel pump and the in-cylinder injector 25. Furthermore, a fuel pressure sensor that detects the pressure of the fuel supplied to the in-cylinder injector 25 may be provided at an arbitrary position.

In-cylinder injector 25 injects fuel into combustion chamber 11a at a predetermined timing in the compression stroke of engine 100 based on an instruction from engine ECU 10. The fuel injected at high pressure atomizes and enters the cavity of the piston 11 and is guided to the vicinity of the spark plug 27 along the shape of the cavity. Then, it is mixed with the intake air supplied when the intake valve 18 is opened during flight, and a mixed gas suitable for combustion of the engine 100 is formed only in the vicinity of the ignition plug 27 at the ignition timing. Realizes combustion of a lean air-fuel mixture, so-called stratified combustion (see FIG. 2). In this case, the in-cylinder injector 25 may be mounted at a position where stratified combustion can be realized when a part of the fuel to be injected at high pressure reaches the spark plug 27 directly.
The in-cylinder injector 25 corresponds to the first fuel injection means of the present invention.

The port injector 26 injects fuel into the intake port 13 at a predetermined timing in the intake stroke of the engine 100 based on an instruction from the engine ECU 10. The high pressure injected fuel is atomized and mixed with the intake air, and becomes a mixed gas suitable for combustion of the engine 100. Then, by supplying the mixed gas to the combustion chamber 11a when the intake valve 18 is opened, so-called homogeneous combustion is realized in which the entire combustion chamber is combusted with the same air-fuel ratio (see FIG. 2). In this case, stratified combustion and homogeneous combustion may be realized by injecting and supplying fuel only with the in-cylinder injector 25 without providing the port injector 26.
The port injector 26 corresponds to the second fuel injection means of the present invention.

  The combustion chamber 11a of each cylinder is provided with an ignition plug 27, and the ignition timing of the ignition plug 27 is adjusted by an igniter 28. The intake air and the mixed gas flowing in from the intake port 13 are mixed with the fuel injected from the in-cylinder injector 25 in the cylinder, and are compressed in the combustion chamber 11 a by the upward movement of the piston 11. The engine ECU 10 determines the ignition timing based on the position of the piston 11 from the crank angle sensor 31 and the cam shaft rotation phase information from the intake cam angle sensor 32 and sends a signal to the igniter 28. The igniter 28 energizes the spark plug 27 with electric power from the battery at the instructed ignition timing in accordance with a signal from the engine ECU 10. The spark plug 27 is ignited by electric power from the battery, ignites the compressed mixed gas, expands the inside of the combustion chamber 11a, and lowers the piston 11. The descending motion is changed to the axial rotation of the crankshaft 12 through the connecting rod, whereby the engine 100 obtains power.

When the exhaust valve 19 is opened, the exhaust gas after combustion merges in the merged exhaust passage 17 through the exhaust port 15 and the exhaust passage 16, passes through the purification catalyst 29, and is discharged to the outside of the engine 100. The purification catalyst 29 is used to purify the exhaust gas of the engine 100. For example, a three-way catalyst or a NOx occlusion reduction type catalyst is applied. A plurality of the purification catalysts 29 may be used in combination depending on the displacement of the engine 100, the use area, and the like.
The combined exhaust passage 17 is provided with an exhaust temperature sensor 36, an A / F sensor 37, and an O2 sensor 38, which detects the temperature and air-fuel ratio of the exhaust gas discharged from the combustion chamber 11a, and sends the results to the engine ECU 10. And send. Further, the purification catalyst 29 is provided with a catalyst temperature sensor 40, which detects the temperature of the purification catalyst 29 and transmits the result to the engine ECU 10.

The vapor passage 41 introduces vaporized fuel in the fuel tank into the canister 42 by communicating a fuel tank (not shown) with the canister 42. The canister 42 is made of an adsorbent such as activated carbon, and is configured to trap vaporized fuel generated from the fuel tank.
The purge passage 43 allows the vaporized fuel stored in the canister 42 to be introduced into the intake passage 14 by communicating the canister 42 with the intake passage 14 downstream of the throttle valve 24. In this case, the purge passage 43 may connect the canister 42 and the intake passage 14 upstream of the throttle valve 24.
A purge control valve 44 is provided in the purge passage 43. As the purge control valve 44, a known adjustment valve such as a butterfly type or a solenoid type that can be adjusted by an actuator or the like can be applied. The purge control valve 44 adjusts the flow rate of the vaporized fuel gas flowing in the purge passage 43 to the intake passage 14 to a desired amount in accordance with an instruction from the engine ECU 10. When the purge control valve 44 is opened, a negative pressure is introduced to the canister 42, and the vaporized fuel trapped in the canister 42 is introduced into the intake passage 14 as purge gas together with the atmosphere introduced from the atmosphere introduction port (not shown).
The vapor passage 41, the canister 42, and the purge passage 43 correspond to the vaporized fuel introducing means of the present invention. The purge control valve 44 corresponds to the introduction amount limiting means of the present invention.

The engine ECU 10 includes a CPU (Central Processing Unit) that performs arithmetic processing, a ROM (Read Only Memory) that stores programs, a RAM (Random Access Memory) and NVRAM (Non Volatile RAM) that store data and the like. Computer. The engine ECU 10 reads the detection results of the crank angle sensor 31, the intake cam angle sensor 32, the air flow meter 34, the throttle position sensor 35, the exhaust temperature sensor 36, the water temperature sensor 39, etc., and the operation of the throttle valve 24, the intake valve 18, the exhaust gas The operation operation of the engine 100 such as the operation of the valve 19, the operation of the in-cylinder injector 25 and the port injector 26, the ignition timing of the spark plug 27, etc. are integratedly controlled.
Further, the engine ECU 10 executes a purge process when the vaporized fuel trapped in the canister 42 exceeds a predetermined amount. The engine ECU 10 controls the opening degree of the purge control valve 44 to a desired amount based on the amount of vaporized fuel trapped in the canister 42 and the operating state of the engine 100, purges the vaporized fuel trapped in the canister 42 and intakes it. It is introduced into the passage 14. Here, an arbitrary trap amount less than the maximum trap amount of the canister 42 can be applied as the predetermined amount of trapped vaporized fuel. In this case, the engine ECU 10 may recognize the vaporized fuel amount trapped in the canister 42 from the fuel tank internal pressure, the outside air temperature, the fuel tank internal temperature, or the like, or the vaporized fuel trapped in the canister 42 by other means. The amount may be recognized.

  Then, the engine ECU 10 acquires the combustion information of the combustion chamber 11a based on the detection results of the A / F sensor 37 and the O2 sensor 38, and adjusts the fuel injection amount into the cylinder so as to obtain an optimal combustion state. / B control is executed. By executing this control, it is possible to correct the fuel injection amount so that the air / fuel ratio is suitable for the operation of the engine 100, so that an appropriate air / fuel ratio can be maintained even when the purge process is executed.

  Further, the engine ECU 10 controls the injection ratio between the fuel amount injected and supplied from the in-cylinder injector 25 and the fuel amount injected and supplied from the port injector 26 based on the operating state of the engine 100. Here, the engine ECU 10 performs fuel injection control for injecting fuel into the in-cylinder injector 25 when control for injecting fuel from only the port injector 26 is continued for a predetermined time, and to the intake passage 14 during that time. Limit the amount of vaporized fuel introduced (see FIG. 3).

  When a predetermined port injection condition (for example, idle operation start condition) is satisfied, the engine ECU 10 instructs only the port injector 26 to perform fuel injection and causes the port injection to be executed. Subsequently, the engine ECU 10 executes control for determining whether or not the time for continuously executing the control for injecting fuel only to the port injector 26 exceeds the first threshold value. Here, as the first threshold value, an injection time by only an arbitrary port injector 26 that is considered to deposit deposit on the injection hole of the in-cylinder injector 25 can be applied, for example, 10 to 20 [min]. be able to. In this case, the determination may be made based not only on the time for continuously executing the control for injecting the fuel only to the port injector 26 but also on the accumulated execution time. The engine ECU 10 instructs the in-cylinder injector 25 to perform fuel injection and executes fuel injection control for cleaning the in-cylinder injector 25 when it is determined that the time for which the control is continuously executed exceeds the first threshold value. In this case, the engine ECU 10 causes the in-cylinder injector 25 to inject fuel with an injection force that can sufficiently remove the deposited deposit. At that time, the port injector 26 may be instructed to stop the injection, and the fuel may be injected only into the in-cylinder injector 25, or the fuel injection of the in-cylinder injector 25 and the port injector 26 may be used in combination.

  The engine ECU 10 executes control for reducing the amount of vaporized fuel introduced into the intake passage 14 while cleaning the in-cylinder injector 25. Based on the detection results of the A / F sensor 37 and the O2 sensor 38, the engine ECU 10 calculates the amount of vaporized fuel that can sufficiently perform fuel injection control for cleaning the in-cylinder injector 25. The engine ECU 10 controls the opening of the purge control valve 44 based on the calculation result of the introduction amount when determining that the current introduction amount of vaporized fuel into the intake passage 14 exceeds the calculated introduction amount. Then, the amount of vaporized fuel introduced into the intake passage 14 is adjusted. In this case, for example, when the purge rate is 5 [%] or less, it can be determined that the amount of vaporized fuel introduced can sufficiently perform the fuel injection control for cleaning the in-cylinder injector 25.

  The engine ECU 10 determines whether or not the cleaning of the in-cylinder injector 25 has been sufficiently completed. When it is determined that the in-cylinder injector 25 has been completed, the engine ECU 10 stops the fuel injection from the in-cylinder injector 25 and the vaporized fuel to the intake passage 14 is stopped. Remove the restriction on the amount of introduction. In this case, the engine ECU 10 can determine the completion of cleaning based on the fuel injection time performed by the in-cylinder injector 25, for example, but may determine the completion of cleaning based on other parameters.

By executing this control, when the fuel injection from only the port injector is performed for a predetermined time, the in-cylinder injector is cleaned, and the amount of vaporized fuel introduced into the intake passage during that time is limited. be able to. Accordingly, since the in-cylinder injector can appropriately perform fuel injection for cleaning, in the internal combustion engine including the in-cylinder injector and the port injector, the deposit of the in-cylinder injector can be appropriately removed. Can do.
The engine ECU 10 corresponds to an injection ratio control unit, an air-fuel ratio feedback control unit, a fuel injection control unit, and an introduction amount limiting unit according to the present invention.

  Next, the operation of the vehicle control system 1 will be described along the control flow of the engine ECU 10. FIG. 4 is a flowchart showing an example of processing of the engine ECU 10. The vehicle control system 1 of the present embodiment includes a first fuel injection unit, a second fuel injection unit, an injection ratio control unit, a vaporized fuel introduction unit, an air-fuel ratio feedback control unit, a fuel injection control unit, By providing the introduction amount limiting means, the in-cylinder injection amount injector is cleaned when the fuel injection from only the port injector is performed for a predetermined time, and the amount of vaporized fuel introduced into the intake passage during that time is reduced. Perform control to limit.

  The control of the engine ECU 10 is started when an engine start request is made, that is, when the ignition switch is turned on. First, in step S1, engine ECU 10 determines whether an idle operation start condition of engine 100 is satisfied. Here, the idling operation condition can be determined from the driver's accelerator operation, engine speed, engine cooling water temperature, purification catalyst 29 temperature, and the like. If the idle operation start condition is not satisfied (step S1 / NO), the engine ECU 10 ends the control process. If the idling operation start condition is satisfied (step S1 / YES), the engine ECU 10 proceeds to the next step S2.

  In step S <b> 2, the engine ECU 10 instructs the in-cylinder injector 25 to stop the injection, and performs an idle operation of the engine 100 by fuel injection from only the port injector 26. When the engine ECU 10 finishes the process of step S2, the process proceeds to the next step S3.

  In step S3, the engine ECU 10 determines whether or not the execution time of fuel injection from only the port injector 26 exceeds the first threshold value. Here, since the first threshold value has been described above, a detailed description thereof will be omitted. When the fuel injection execution time from only the port injector 26 does not exceed the first threshold value (step S3 / NO), the engine ECU 10 determines that the in-cylinder injector 25 does not need to be cleaned, and ends the control process. To do. When the execution time of fuel injection from only the port injector 26 exceeds the first threshold value (step S3 / YES), the engine ECU 10 determines that the in-cylinder injector 25 needs to be cleaned, and the next step S4 Proceed to

  In step S4, the engine ECU 10 calculates an introduction amount of vaporized fuel that can sufficiently perform fuel injection for cleaning the in-cylinder injector 25 based on the detection results of the A / F sensor 37 and the O2 sensor 38. Subsequently, the engine ECU 10 determines whether or not the current introduction amount of vaporized fuel into the intake passage 14 exceeds the calculated introduction amount. When the current introduction amount of vaporized fuel into the intake passage 14 does not exceed the calculated introduction amount (step S4 / NO), the engine ECU 10 determines that there is no need to limit the introduction amount of vaporized fuel into the intake passage 14. Then, the control process ends. If the current amount of vaporized fuel introduced into the intake passage 14 exceeds the calculated amount introduced (step S4 / YES), the engine ECU 10 determines that the amount of vaporized fuel introduced into the intake passage 14 needs to be limited. Then, the process proceeds to the next step S5.

  In step S <b> 5, the engine ECU 10 controls the opening degree of the purge control valve 44 based on the calculation result calculated in step S <b> 4 and limits the amount of vaporized fuel introduced into the intake passage 14. After finishing the process of step S5, the engine ECU 10 proceeds to the next step S6.

  In step S <b> 6, the engine ECU 10 instructs the in-cylinder injector 25 to inject fuel, and removes deposits attached to the in-cylinder injector 25. After finishing the process of step S6, the engine ECU 10 proceeds to the next step S7.

  In step S7, the engine ECU 10 determines whether or not the fuel injection time of the in-cylinder injector 25 exceeds a predetermined time. Here, the predetermined time can be an injection time that can sufficiently remove deposits adhering to the in-cylinder injector 25, and can be, for example, 5 to 10 [min]. When the fuel injection time of the in-cylinder injector 25 does not exceed the predetermined time (step S7 / NO), the engine ECU 10 determines that the deposit attached to the in-cylinder injector 25 has not been sufficiently removed, and returns to step S6. The above process is repeated until the fuel injection time of the in-cylinder injector 25 exceeds a predetermined time. If the fuel injection time of in-cylinder injector 25 exceeds the predetermined time (step S7 / YES), engine ECU 10 determines that the deposit adhering to in-cylinder injector 25 has been sufficiently removed, and proceeds to the next step S8.

In step S <b> 8, the engine ECU 10 stops fuel injection from the in-cylinder injector 25 and releases the restriction on the amount of vaporized fuel introduced into the intake passage 14.
By executing this control, when the in-cylinder injector is cleaned when fuel injection from only the port injector is performed for a predetermined time, the injection amount of the in-cylinder injector is F / B. It is possible to suppress the reduction correction by the control. Accordingly, since the in-cylinder injector can appropriately perform fuel injection for cleaning, in the internal combustion engine including the in-cylinder injector and the port injector, the deposit of the in-cylinder injector can be appropriately removed. Can do.
The engine ECU 10 ends the control process when the process of step S8 is completed.

  As described above, the vehicle control system 1 of the present embodiment includes the first fuel injection means, the second fuel injection means, the injection ratio control means, the vaporized fuel introduction means, the air-fuel ratio feedback control means, the fuel When the fuel injection from only the port injector is performed for a predetermined period by the injection control means and the introduction amount limiting means, the in-cylinder injection amount cleaning is performed, and the vaporized fuel is introduced into the intake passage during that period. By limiting the amount, the in-cylinder injector can appropriately perform fuel injection for cleaning.In an internal combustion engine including the in-cylinder injector and the port injector, the deposit of the in-cylinder injector is reduced. Can be removed appropriately.

  Next, a second embodiment of the present invention will be described. The vehicle control system 2 of the present embodiment is different from the vehicle control system 1 in that the introduction amount restriction means restricts the introduction amount by the vaporized fuel introduction means based on the correction amount of the air-fuel ratio executed by the feedback control means. .

  Similar to the first embodiment, the vehicle control system 2 of the present embodiment includes an engine ECU 10 inside the vehicle. The vehicle control system 2 includes a purge control valve 44 in the purge passage 43. The engine ECU 10 and the purge control valve 44 execute control for limiting the amount of vaporized fuel introduced into the intake passage 14 based on the air-fuel ratio correction amount executed by the F / B control.

  When the engine ECU 10 performs the cleaning of the in-cylinder injector 25, the correction amount of the air-fuel ratio by the F / B control executed based on the detection results of the A / F sensor 37 and the O2 sensor 38 is the second threshold. Control is performed to determine whether or not the value is less than the value. Here, as the second threshold value, a state in which the air-fuel ratio of the internal combustion engine is on the lean side and the fuel injection amount is increased to correct the air-fuel ratio to the rich side can be applied. It can be set to 0 to 3 [%]. When the engine ECU 10 determines that the correction amount of the air-fuel ratio by the F / B control is greater than or equal to the second threshold value, the engine ECU 10 limits the amount of vaporized fuel introduced into the intake passage 14 while the in-cylinder injector 25 is being cleaned. You can avoid it. On the other hand, when the engine ECU 10 determines that the correction amount of the air-fuel ratio by the F / B control is less than the second threshold value, the amount of vaporized fuel introduced into the intake passage 14 during execution of the cleaning of the in-cylinder injector 25. Execute control to limit

  By executing this control, only when the correction amount of the air-fuel ratio by the F / B control is less than the second threshold value, that is, only when the air-fuel ratio is corrected to the lean side by the F / B control, the intake passage 14 Since the amount of vaporized fuel introduced into the fuel can be limited, the amount of vaporized fuel introduced can be limited as much as possible.

Next, the operation of the vehicle control system 2 will be described along the control flow of the engine ECU 10. FIG. 5 is a flowchart showing an example of processing of the engine ECU 10. The engine ECU 10 of the vehicle control system 2 controls the following step S9 during the processing from step S1 to step S3 and from step S4 to step S8 of the vehicle control system 1 of the first embodiment. Therefore, since the control from step S1 to step S3 and from step S4 to step S8 is the same as that of the vehicle control system 1 of the first embodiment, detailed description thereof is omitted.
In the vehicle control system 2 of the present embodiment, the introduction amount restriction unit performs control for restricting the introduction amount by the vaporized fuel introduction unit based on the correction amount of the air-fuel ratio performed by the feedback control unit.

  If the determination in step S3 is yes, the engine ECU 10 proceeds to step S9. In step S9, the engine ECU 10 determines whether the correction amount of the air-fuel ratio by the F / B control executed based on the detection results of the A / F sensor 37 and the O2 sensor 38 is less than the second threshold value. To do. Here, since the second threshold value has been described above, a detailed description thereof will be omitted. When the correction amount of the air-fuel ratio by the F / B control is not less than the second threshold value (step S9 / NO), the engine ECU 10 determines that there is no need to limit the amount of vaporized fuel introduced into the intake passage 14, The control process ends. If the correction amount of the air-fuel ratio by the F / B control is less than the second threshold value (step S9 / YES), the engine ECU 10 determines that it is necessary to limit the amount of vaporized fuel introduced into the intake passage 14. Then, the processing after the next step S4 is executed.

  By executing this control, when the correction amount of the air-fuel ratio by the F / B control is less than the second threshold value, that is, when the air-fuel ratio is corrected to the lean side by the F / B control, the in-cylinder injector The amount of vaporized fuel introduced into the intake passage 14 can be limited during the cleaning of 25. On the other hand, when the correction amount of the air-fuel ratio by the F / B control is greater than or equal to the second threshold value, the amount of vaporized fuel introduced into the intake passage 14 should not be limited while the in-cylinder injector 25 is being cleaned. Can do. Therefore, it is possible to minimize the amount of vaporized fuel introduced.

  As described above, the vehicle control system 2 according to the present embodiment is configured so that the introduction amount restriction unit restricts the introduction amount by the vaporized fuel introduction unit based on the air fuel ratio correction amount executed by the feedback control unit. Only when the air-fuel ratio is corrected to the lean side by the control, the amount of vaporized fuel introduced into the intake passage 14 can be limited. Therefore, it is possible to minimize the amount of vaporized fuel introduced during the cleaning of the in-cylinder injector.

  The above embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to these, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

  For example, by performing control that alternately repeats fuel injection from the in-cylinder injector and introduction of vaporized fuel into the intake passage, both in-cylinder injector cleaning and purge processing control can be achieved, and vaporization into the intake passage It is also possible to limit the amount of fuel introduced as much as possible.

1 vehicle control system 10 engine ECU (split ratio control means, air-fuel ratio feedback control means, fuel injection control means, introduction amount limiting means)
DESCRIPTION OF SYMBOLS 11 Piston 11a Combustion chamber 12 Crankshaft 13 Intake port 14 Intake passage 15 Exhaust port 16 Exhaust passage 17 Confluence exhaust passage 18 Intake valve 19 Exhaust valve 20 Intake camshaft 21 Exhaust camshaft 22 Electric VVT mechanism 23 Hydraulic VVT mechanism 24 Throttle valve 25 In-cylinder injector (first fuel injection means)
26 Port injector (second fuel injection means)
27 Spark plug 28 Igniter 29 Purification catalyst 31 Crank angle sensor 32 Intake cam angle sensor 33 Exhaust cam angle sensor 34 Air flow meter 35 Throttle position sensor 36 Exhaust temperature sensor 37 A / F sensor 38 O2 sensor 39 Water temperature sensor 40 Catalyst temperature sensor 41 Vapor Passage (vaporized fuel introduction means)
42 Canister (Vaporized fuel introduction means)
43 Purge passageway (vaporized fuel introduction means)
44 Purge control valve (introduction amount limiting means)
100 engine

Claims (2)

The first fuel injection means for injecting and supplying fuel to the combustion chamber of the internal combustion engine, the second fuel injection means for injecting and supplying fuel to the intake passage of the internal combustion engine, and the first fuel injection means based on the operating state of the internal combustion engine. An injection ratio control means for controlling an injection ratio between an amount of fuel supplied and supplied by the fuel injection means and an amount of fuel supplied and supplied by the second fuel injection means; and vaporized fuel in a fuel supply source of the internal combustion engine as an intake passage A control device for an internal combustion engine, comprising: vaporized fuel introduction means to be introduced into the air-fuel ratio; and air-fuel ratio feedback control means for correcting the air-fuel ratio to a target air-fuel ratio according to the operating state of the internal combustion engine,
Fuel injection control for causing the first fuel injection means to inject the fuel for a predetermined time when the time for executing the control for causing the injection dividing control means to inject fuel only to the second fuel injection means exceeds the first threshold value Means,
An introduction amount restriction means for restricting an introduction amount by the vaporized fuel introduction means while the fuel injection control means is executed;
A control device for an internal combustion engine, comprising:   2. The control of an internal combustion engine according to claim 1, wherein the introduction amount restriction means restricts the introduction amount by the vaporized fuel introduction means based on an air-fuel ratio correction amount executed by the air-fuel ratio feedback control means. apparatus.

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