JP2010096049A - Control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the suppression of deterioration of emission highly compatible with the control of turbo lag during transient operation due to acceleration in an internal combustion engine with a supercharger containing a waste gate valve. <P>SOLUTION: A control device of an internal combustion engine with a supercharger containing a waste gate valve (WGV) 48, is equipped with an EGR control means for controlling an opening of the EGR valve 44 to a target opening in response to output request to internal combustion engine, a determination means for determining whether or not a prescribed acceleration request to the internal combustion engine is detected, and a waste gate valve control means for operating the WGV 48 to a close side when the prescribed acceleration request is determined to be detected. The EGR control means reduces an opening of the EGR valve 44 for a prescribed period containing a period for executing the waste gate valve control means than a target opening. Preferably, the opening of the EGR valve 44 is reduced than the target opening prior to the execution of the waste gate valve control means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for a supercharged internal combustion engine having a wastegate valve.

  Conventionally, for example, as disclosed in Japanese Patent Application Laid-Open No. 2000-205055, in an engine with a turbocharger, in order to prevent an excessive increase in exhaust gas recirculation (EGR) due to an increase in exhaust pressure during acceleration. A control apparatus has been proposed. In this control apparatus, as a means for adjusting the exhaust pressure upstream of the turbine, a variable blade that forms a nozzle whose opening degree can be changed with respect to the turbine of the supercharger is provided. Then, at the initial stage of acceleration when accelerating from the EGR region, the variable blades are opened to control the exhaust pressure upstream of the turbine to decrease. When the exhaust pressure decreases, the differential pressure between the exhaust pressure and the intake pressure decreases, so the EGR amount becomes small. For this reason, according to the conventional control device, it is possible to prevent the amount of EGR from excessively increasing, and to improve acceleration and emission.

JP 2000-205055 A JP 2005-83362 A JP 2007-92757 A

  However, the conventional control device does not take measures against the turbo lag. That is, if the exhaust pressure is reduced in order to prevent an excessive increase in the EGR amount, a turbo lag appears remarkably in the early stage of acceleration. Therefore, in the conventional control device, it is difficult to achieve both improvement in emission by controlling the EGR amount and suppression of turbo lag.

  This problem is similarly assumed in, for example, a supercharged internal combustion engine having a wastegate valve. That is, in a supercharged internal combustion engine having a wastegate valve, when an output (acceleration) request for the internal combustion engine is detected, the wastegate valve may be transiently controlled to be closed. Thereby, since the amount of exhaust gas flowing into the turbine of the supercharger can be increased, turbo lag can be effectively suppressed. However, when the wastegate valve is controlled to the closed side, the exhaust pressure increases. For this reason, when the opening degree of the EGR valve is set without considering the transient operation of the wastegate valve, the EGR amount becomes excessive as the differential pressure between the exhaust pressure and the intake pressure increases. It is assumed that a desired EGR amount cannot be realized. In such a case, misfire or the like due to a decrease in combustion temperature may occur.

  The present invention has been made to solve the above-described problems, and in an internal combustion engine with a supercharger having a wastegate valve, it has a high level of suppression of deterioration of emissions and suppression of turbo lag during transient operation due to acceleration. An object of the present invention is to provide a control device for an internal combustion engine that can be compatible with each other.

In order to achieve the above object, a first invention is a control device for an internal combustion engine,
In a control device for an internal combustion engine with a supercharger having a wastegate valve,
An EGR passage connecting an exhaust passage and an intake passage of the internal combustion engine;
An EGR valve disposed in the EGR passage;
EGR control means for controlling the opening of the EGR valve to a target opening corresponding to an output request for the internal combustion engine;
Determination means for determining whether or not a predetermined acceleration request for the internal combustion engine is detected;
A wastegate valve control means for operating the wastegate valve to the closed side when it is determined that the predetermined acceleration request is detected;
The EGR control means reduces the opening degree of the EGR valve during a predetermined period including a period during which the waste gate valve control means is executed from the target opening degree.

According to a second invention, in the first invention,
The EGR control means reduces the opening degree of the EGR valve from the target opening degree prior to the execution of the waste gate valve control means.

According to a third invention, in the first or second invention,
The EGR control means controls the opening of the EGR valve in the predetermined period to be fully closed when the engine speed of the internal combustion engine is in a predetermined low rotation range.

  According to the first invention, when a predetermined acceleration request for the internal combustion engine is detected and the wastegate valve is operated to the closed side, the opening degree of the EGR valve is controlled to be smaller than the target opening degree. When the wastegate valve is operated to the closed side, the differential pressure between the back pressure and the supercharging pressure upstream of the supercharger increases transiently. According to the present invention, since the opening degree of the EGR valve during the predetermined period is controlled to be smaller than the target opening degree, it is possible to effectively prevent a situation in which the EGR amount increases as the differential pressure increases. For this reason, according to the present invention, it is possible to achieve both the suppression of turbo lag and the suppression of emission deterioration at a high level during transient operation by acceleration of the internal combustion engine.

  According to the second aspect of the invention, when the waste gate valve is controlled to the closed side, the EGR valve is controlled to a predetermined opening smaller than the target opening before such operation. When the wastegate valve is closed, the back pressure upstream of the turbocharger in the exhaust passage rises with good responsiveness. For this reason, according to this invention, the increase in the amount of EGR immediately after controlling a wastegate valve to the closed side can be suppressed effectively.

  According to the third invention, when the engine speed of the internal combustion engine is in a predetermined low rotation range, the opening degree of the EGR valve for a predetermined period is controlled to be fully closed. The exhaust gas temperature decreases as the EGR amount decreases. For this reason, according to the present invention, in the low rotation region where the supercharging response is poor, the exhaust energy is effectively increased to suppress the occurrence of turbo lag, and the occurrence of misfire is suppressed to suppress the deterioration of emissions. Can do.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted. The present invention is not limited to the following embodiments.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1 is a diagram for explaining a schematic configuration of an internal combustion engine system as a first embodiment of the present invention. As shown in FIG. 1, the system of the present embodiment includes a four-cycle diesel engine 10 having a plurality of cylinders (four cylinders in FIG. 1). It is assumed that the diesel engine 10 is mounted on a vehicle and used as a power source.

  Hereinafter, although this embodiment demonstrates the case where this invention is applied to control of a diesel engine (compression ignition internal combustion engine), this invention is not limited to a diesel engine, A gasoline engine (spark ignition internal combustion engine) It can be applied to control of various other internal combustion engines.

  Each cylinder of the diesel engine 10 is provided with an injector 12 for directly injecting fuel into the cylinder. The injectors 12 of each cylinder are connected to a common common rail 14. Fuel in a fuel tank (not shown) is pressurized to a predetermined fuel pressure by a supply pump 16, stored in the common rail 14, and supplied from the common rail 14 to each injector 12.

  An exhaust passage 18 of the diesel engine 10 is branched by an exhaust manifold 20 and connected to an exhaust port (not shown) of each cylinder. The exhaust passage 18 is connected to the exhaust turbine of the turbocharger 24. A post-treatment device 26 for purifying exhaust gas is provided downstream of the turbocharger 24 in the exhaust passage 18. As the post-processing device 26, for example, an oxidation catalyst, a NOx catalyst, a DPF (Diesel Particulate Filter), a DPNR (Diesel Particulate-NOx-Reduction system), or the like can be used.

  An air cleaner 30 is provided near the inlet of the intake passage 28 of the diesel engine 10. The air drawn through the air cleaner 30 is compressed by the intake compressor of the turbocharger 24 and then cooled by the intercooler 32. The intake air that has passed through the intercooler 32 is distributed by an intake manifold 34 to intake ports (not shown) of each cylinder.

  An intake throttle valve 36 is installed between the intercooler 32 and the intake manifold 34 in the intake passage 28. An air flow meter 52 for detecting the amount of intake air is installed in the intake passage 28 near the downstream of the air cleaner 30.

  One end of an EGR (Exhaust Gas Recirculation) passage 40 is connected to the vicinity of the intake manifold 34 in the intake passage 28. The other end of the EGR passage 40 is connected to the vicinity of the exhaust manifold 20 in the exhaust passage 18. In the present system, a part of the exhaust gas (burned gas) can be recirculated to the intake passage 28 through the EGR passage 40, that is, external EGR can be performed. Hereinafter, the exhaust gas recirculated to the intake passage 28 through the EGR passage 40 is referred to as “external EGR gas”.

  In the middle of the EGR passage 40, an EGR cooler 42 for cooling the external EGR gas is provided. An EGR valve 44 is provided downstream of the EGR cooler 42 in the EGR passage 40. By changing the opening of the EGR valve 44, the amount of exhaust gas passing through the EGR passage 40, that is, the amount of external EGR can be adjusted.

  An intake pressure sensor 54 for detecting the intake pressure is installed downstream of the intake throttle valve 36 in the intake passage 28. Further, a back pressure sensor 56 for detecting a back pressure is installed upstream of the turbocharger 24 in the exhaust passage 18.

  The internal combustion engine system shown in FIG. 1 includes an exhaust bypass passage 46 and a waste gate valve (hereinafter referred to as “WGV”) 48. More specifically, the exhaust bypass passage 46 is connected to the exhaust passage 18 as a passage connecting the vicinity of the exhaust upstream side and the vicinity of the exhaust downstream side of the turbocharger 24. Further, the WGV 48 is disposed in the middle of the exhaust bypass passage 46. When the WGV 48 is opened, a part of the exhaust gas flows bypassing the turbine of the turbocharger 24. The WGV 48 is driven by an actuator 58 and its opening degree is electronically controlled.

  The system according to the present embodiment includes an ECU (Electronic Control Unit) 50 as shown in FIG. In addition to the air flow meter 52, the intake pressure sensor 54, and the back pressure sensor 56 described above, the ECU 50 includes an accelerator position sensor 60 for detecting the amount of depression of the accelerator pedal (accelerator opening), and a crank of the diesel engine 10. Various sensors for controlling the diesel engine 10 such as a crank angle sensor 62 for detecting the angle are connected. In addition to the injector 12, the intake throttle valve 36, the EGR valve 44, and the actuator 58 described above, various actuators for controlling the diesel engine 10 are connected to the output unit of the ECU 50. The ECU 50 drives each device in accordance with a predetermined program based on various types of input information.

[Operation of Embodiment 1]
(Control of external EGR)
The external EGR is performed by returning a part of the exhaust gas (burned gas) to the intake passage 28 through the EGR passage 40. More specifically, the opening degree of the EGR valve 44 is adjusted according to the operating state of the diesel engine 10, and the exhaust gas is introduced into the EGR passage 40. The introduced exhaust gas is cooled in the EGR cooler 42 and then returned to the intake passage 28.

The external EGR amount is controlled based on the oxygen concentration (intake O ₂ concentration) in the gas sucked into the cylinder. That is, the intake O ₂ concentration has a correlation with the EGR rate. The intake O ₂ concentration is detected by the intake air amount detected by the air flow meter 52, the opening of the EGR valve 44, the intake pressure (supercharging pressure) detected by the intake pressure sensor 54, and the back pressure sensor 56. It can be estimated based on back pressure or the like. Therefore, if the estimated value of the intake O ₂ concentration is calculated based on these values, and the opening degree of the EGR valve 44 is controlled so that the estimated value matches the target value according to the operating state, the external EGR becomes the target. The EGR rate can be controlled as follows.

In the system of the present embodiment, the relationship between the operating state of the diesel engine 10 and the intake O ₂ concentration for realizing an appropriate EGR rate according to the operating state is mapped and stored in the ECU 50 in advance. It shall be. Then, the ECU 50 feedback-controls the opening degree of the EGR valve 44 so that the estimated intake O ₂ concentration matches the target value determined according to the map.

[Characteristic Operation of First Embodiment]
Next, a characteristic operation of the present embodiment will be described with reference to FIGS. As described above, during the steady operation of the diesel engine 10, the opening of the EGR valve 44 for realizing a desired EGR rate is specified according to the map.

  Here, the diesel engine 10 of the present embodiment includes a turbocharger 24 having a WGV 48. When the WGV 48 is controlled to open, a part of the exhaust gas flows to the exhaust bypass passage 46 side. Therefore, the exhaust resistance can be effectively reduced by controlling the WGV 48 to the open side in the operating state that is not in the supercharging region. On the other hand, when the WGV 48 is controlled to the closed side, the amount of exhaust gas flowing into the turbine of the turbocharger 24 can be increased. For this reason, when the output request | requirement with respect to the diesel engine 10 is detected, if WGV48 shall be controlled to the close side transiently, generation | occurrence | production of a turbo lag can be suppressed effectively.

  However, when the WGV 48 is controlled to the closed side, the back pressure rises before the intake pressure rises. For this reason, the differential pressure between the intake pressure and the back pressure temporarily increases from the steady state. As described above, the map that defines the opening degree of the EGR valve 44 is defined on the assumption of a steady state. For this reason, during such transient operation, if the EGR amount is controlled according to a map based on the steady state, the amount of EGR increases as the differential pressure increases, and the emission may be deteriorated. is there.

  Therefore, in the first embodiment, when a predetermined acceleration request (supercharging request) to the diesel engine 10 is detected and the WGV 48 is operated from the opening side to the closing side, the differential pressure between the intake pressure and the back pressure. The opening degree of the EGR valve 44 is set in consideration of the increase in the value, and a desired EGR rate is realized. FIG. 2 is a timing chart of various operating states when an acceleration request for the diesel engine 10 is detected. FIG. 3 is a diagram showing the relationship between the opening degree of the EGR valve 44 and the EGR amount when the EGR rate is constant during transient operation due to acceleration of the diesel engine 10. The states A to D in FIG. 3 correspond to the states A to D in FIG.

  As shown in FIG. 2, during the period from state B to state C in which the WGV 48 is controlled to the closed side, the differential pressure between the back pressure and the intake pressure changes transiently. More specifically, the back pressure rises with good responsiveness in the state B in which the WGV 48 is operated to the closed side. On the other hand, the intake pressure gradually increases during the period from state B to state C after the back pressure increases due to the structure of the turbocharger 24. For this reason, the differential pressure between the back pressure and the intake pressure suddenly increases in the state B in which the WGV 48 is operated to the closed side.

  Therefore, in the present embodiment, the opening degree of the EGR valve 44 is controlled to a predetermined small opening degree before the state B in which the WGV 48 is operated to the closing side. More specifically, the opening degree of the EGR valve 44 is changed to a predetermined small opening degree during the period from the state A to the state B so that a desired EGR rate is realized in the state B. In other words, when the supercharging request is issued in the state A, the operation of the WGV 48 is limited to the state B where the opening degree of the EGR valve 44 becomes a predetermined small opening degree. Thereby, a desired EGR rate can be realized in the state B in which the WGV 48 is operated to the closed side.

  Further, as shown in FIG. 2, the differential pressure changes transiently during the period from state B to state C in which the WGV 48 is operated to the closed side. Therefore, in the present embodiment, the opening degree of the EGR valve 44 is feedback-controlled so that the EGR rate does not increase beyond a desired ratio due to an increase in the differential pressure. More specifically, during the period from state B to state C, the operating state such as the amount of air to be sucked in and the differential pressure is the opening degree of the EGR valve 44 so that the EGR rate becomes a desired ratio (for example, constant). Provide feedback. Thereby, while suppressing the turbo lag at the time of transition until it transfers to the stable supercharging area | region, the situation where exhaust emission deteriorates can be suppressed effectively.

  When the desired boost pressure is reached in the state D, the opening degree of the EGR valve 44 is controlled to a predetermined small opening degree from the state C prior to this as shown in FIG. Thereby, immediately after operating the WGV 48 to the open side in the state D, it is possible to effectively prevent a situation in which the EGR rate increases from a desired rate.

  As described above, according to the system of the present embodiment, the opening degree of the EGR valve 44 is controlled to the opening degree considering the opening / closing of the WGV 48 prior to the opening / closing operation of the WGV 48. For this reason, it is possible to effectively suppress the generation of turbo lag during the transient operation that shifts to the supercharging state, and to control the EGR amount optimally, thereby suppressing the deterioration of the exhaust emission.

[Specific Processing in Embodiment 1]
Next, with reference to FIG. 4, the specific content of the process performed in this Embodiment is demonstrated. FIG. 4 is a flowchart of a routine in which the ECU 50 executes EGR control at the time of transition to the supercharging state.

  In the routine shown in FIG. 4, first, the accelerator opening is read (step 100). Specifically, the signal from the accelerator position sensor 60 is read as the accelerator opening.

  Next, the required air amount is calculated (step 102). Here, specifically, the required air amount is calculated based on the accelerator opening read in step 100.

  Next, it is determined whether or not the required air amount is in the supercharging region (step 104). Specifically, it is determined whether or not the required air amount calculated in step 102 is an air amount that requires supercharging. As a result, when it is determined that the required air amount is not in the supercharging region, it is not necessary to perform the closing operation of the WGV 48, so it is determined that the EGR amount does not deviate from the desired amount, and the next step is performed. Then, the opening / closing permission of the WGV 48 is turned off (step 106). Here, specifically, the opening / closing operation of the WGV 48 is prohibited, and then this routine is immediately terminated.

  On the other hand, if it is determined in step 104 that the required air amount is in the supercharging region, it is determined that the WGV 48 needs to be closed, and the process proceeds to the next step. It is determined whether or not the difference between the required air amount and the required air amount in this routine is greater than a predetermined value (step 108). Specifically, the difference between the required air amount calculated in step 102 in the previous routine and the required air amount calculated in step 102 in the present routine is calculated, and the difference between the difference and the predetermined value is calculated. Big and small are compared. As the predetermined value, a preset value is used as a threshold value for determining whether or not an acceleration request is issued to the diesel engine 10, that is, whether or not it is a stable supercharging region. As a result, when it is determined that the difference between the required air amount in the previous routine and the required air amount in the present routine is not larger than a predetermined value, the operation state of the diesel engine 10 is in a stable supercharging region. If it is determined that the operating state is not a transient state, the process proceeds to step 106, the permission for opening / closing the WGV 48 is turned OFF, and then this routine is immediately terminated.

  On the other hand, if it is determined in step 108 that the difference between the required air amount in the previous routine and the required air amount in the present routine is greater than a predetermined value, the operating state of the diesel engine 10 is in a transient state. If it is determined that there is, a transition is made to the next step, and it is determined whether or not a request to close the WGV 48 is detected (step 110). When the WGV 48 is operated from the opening side to the closing side, the amount of exhaust gas flowing into the turbine of the turbocharger 24 is increased. That is, specifically, here, it is determined whether or not a request for operating the WGV 48 to the closing side is issued in order to suppress the turbo lag in the supercharging process.

  As a result, when a request to close the WGV 48 is detected, the process proceeds to the next step, and it is determined whether or not the permission to open and close the WGV 48 is OFF (step 112). Here, specifically, it is determined in step 106 whether the opening / closing permission of the WGV 48 is set to OFF. As a result, when it is determined that the opening / closing permission of the WGV 48 is set to OFF, it is determined that the WGV 48 has not yet operated to the closing side, and the process proceeds to the next step, and the WGV 48 is operated to the closing side. The assumed back pressure in the case of being made is estimated (step 114). Here, specifically, the assumed back pressure is calculated based on the target closing degree of the WGV 48 and the amount of air taken into the diesel engine 10.

  In the routine shown in FIG. 4, next, a target EGR valve opening is calculated (step 116). Here, specifically, based on the differential pressure between the assumed back pressure estimated in step 114 and the intake pressure detected by the intake pressure sensor 54, the opening of the EGR valve 44 for realizing the target EGR rate is performed. The degree is calculated.

  Next, the target EGR valve opening is output (step 118). Here, specifically, the opening degree of the EGR valve 44 is adjusted so as to be the target EGR valve opening degree calculated in step 116.

  Next, it is determined whether or not the target EGR opening degree <actual EGR opening degree-α is established (step 120). Specifically, it is determined whether or not the target EGR opening degree output in step 118 is smaller than the actual EGR opening degree -α (α is an allowable error component). As a result, when it is recognized that the target EGR opening <the actual EGR opening−α, it is determined that the actual EGR opening has not yet decreased to the target EGR opening, and this step is repeatedly executed. The

  On the other hand, if the establishment of the target EGR opening <the actual EGR opening−α is not recognized, it is determined that the actual EGR opening has decreased to the target EGR opening, the process proceeds to the next step, and the opening / closing of the WGV 48 The permission is turned on (step 122). Here, specifically, the WGV 48 is operated to the closing side.

  In the routine after the opening / closing permission of the WGV 48 is turned ON in step 122, that is, after the WGV 48 is operated to the closing side, it is determined in step 112 that the opening / closing permission of the WGV 48 is not OFF. In such a case, next, the target EGR opening is calculated based on the actual back pressure (step 124). Here, specifically, the EGR valve 44 for realizing the target EGR rate based on the differential pressure between the actual back pressure detected by the back pressure sensor 56 and the actual intake pressure detected by the intake pressure sensor 54. Is calculated.

  Next, the target EGR opening is output (step 126). Here, specifically, the opening degree of the EGR valve 44 is adjusted so as to be the target EGR opening degree calculated in step 124. Thereafter, the routine of steps 100 to 112, 124, and 126 is repeatedly executed until a request to open the WGV 48 is detected.

  Thereafter, when an opening request for the WGV 48 is detected, processing for operating the WGV 48 to the opening side is executed. More specifically, if the WGV 48 closing request is not detected in step 110, the process proceeds to the next step, and it is determined whether or not the WGV 48 closing request is detected in step 110 in the previous routine. (Step 128). Specifically, it is determined whether a request to open the WGV 48 is detected in step 110 of this routine or whether it has been detected from the previous routine. As a result, if it is determined in the previous routine that a request to close the WGV 48 has been detected, it is determined from this routine that a request to open the WGV 48 has been detected. Assumed back pressure is estimated when operated. Next, based on the assumed back pressure calculated in step 114, the target EGR valve opening is calculated. Next, the target EGR valve opening is output. Next, it is determined whether or not the target EGR opening degree <the actual EGR opening degree-α is established. Here, specifically, the same processing as in steps 116 to 120 is executed.

  Next, when the establishment of the target EGR opening <the actual EGR opening-α is not recognized in step 120, the process proceeds to step 122, and the opening / closing permission of the WGV 48 is turned ON (step 122). Here, specifically, it is operated to the WGV 48 opening side.

  On the other hand, in step 128, if it is determined in step 110 in the previous routine that the closing request for the WGV 48 has not been detected, it is determined that the opening operation of the WGV 48 has already been performed, and the routine proceeds to step 106. After the opening / closing permission of the WGV 48 is turned off, this routine is immediately terminated.

  As described above, according to the system of the first embodiment, when the WGV 48 is opened / closed transiently, the opening degree of the EGR valve 44 is controlled prior to this operation. For this reason, it is possible to effectively suppress the generation of turbo lag during the transient operation that shifts to the supercharging state and optimally control the EGR amount to suppress the deterioration of the exhaust emission.

  By the way, in Embodiment 1 mentioned above, when performing closing operation of WGV48, prior to this, the opening degree of EGR valve 44 is controlled to a predetermined small opening degree. The opening is not limited to this. FIG. 5 is a diagram illustrating timing charts of various operation states when an acceleration request for the diesel engine 10 is detected. As shown in this figure, for example, the EGR valve 44 may be controlled to be fully closed in a low rotation range where the supercharging response is poor. Thereby, since exhaust gas temperature can be raised and exhaust energy can be increased, generation | occurrence | production of a turbo lag can be suppressed effectively, suppressing generation | occurrence | production of misfire.

  In the first embodiment, the diesel engine 10 corresponds to the “internal combustion engine” in the first invention, and the turbocharger 24 corresponds to the “supercharger” in the first invention. Yes. Further, when the ECU 50 executes the process of step 122, the “waist gate valve control means” in the first aspect of the invention executes the process of step 118 or 126, so that the first aspect of the invention is achieved. The “EGR control means” in FIG.

  In the first embodiment described above, the “EGR control means” according to the second aspect of the present invention is realized by the ECU 50 executing the processing of step 118.

It is a figure for demonstrating schematic structure of the system of Embodiment 1 of this invention. It is a figure which shows the timing chart of the various driving | running states when the acceleration request | requirement with respect to a diesel engine is detected. It is a figure which shows the relationship between the opening degree of the EGR valve | bulb 44, and the amount of EGR when the EGR rate is made constant at the time of transient operation by acceleration of a diesel engine. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a figure which shows the timing chart of the various driving | running states when the acceleration request | requirement with respect to a diesel engine is detected.

Explanation of symbols

10 Diesel engine (engine)
12 Injector 14 Common rail 16 Supply pump 18 Exhaust passage 20 Exhaust manifold 24 Turbocharger 26 After-treatment device 28 Intake passage 30 Air cleaner 32 Intercooler 34 Intake manifold 36 Inlet throttle valve 40 EGR passage 42 EGR cooler 44 EGR valve 46 Exhaust bypass passage 48 Wastegate valve (WGV)
50 ECU (Electronic Control Unit)
52 Air Flow Meter 54 Intake Pressure Sensor 56 Back Pressure Sensor 58 Actuator 60 Acceleration Position Sensor 62 Crank Angle Sensor

Claims (3)

In a control device for an internal combustion engine with a supercharger having a wastegate valve,
An EGR passage connecting an exhaust passage and an intake passage of the internal combustion engine;
An EGR valve disposed in the EGR passage;
EGR control means for controlling the opening of the EGR valve to a target opening corresponding to an output request for the internal combustion engine;
Determination means for determining whether or not a predetermined acceleration request for the internal combustion engine is detected;
A wastegate valve control means for operating the wastegate valve to the closed side when it is determined that the predetermined acceleration request is detected;
The control apparatus for an internal combustion engine, wherein the EGR control means reduces an opening degree of the EGR valve during a predetermined period including a period during which the waste gate valve control means is executed, from the target opening degree.   2. The control apparatus for an internal combustion engine according to claim 1, wherein the EGR control means reduces the opening degree of the EGR valve from the target opening degree prior to the execution of the waste gate valve control means.   The EGR control means controls the opening degree of the EGR valve in the predetermined period to be fully closed when the engine speed of the internal combustion engine is in a predetermined low rotation range. The internal combustion engine control device described.

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