JP2012107525A - Recirculation control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a recirculation control device of an internal combustion engine which can more certainly reduce production of nitrogen oxide at starting of an internal combustion engine.SOLUTION: The recirculation control device of the internal combustion engine includes: a return channel 38 which connects an exhaust channel 36 and an intake channel 16 to recirculate exhaust gas; and an adjustment means which adjusts exhaust gas quantity to be recirculated from the return channel 38 to the intake channel 16. Further, the recirculation control device includes: an operating condition detection means which detects operating condition of the internal combustion engine 1; a start determination means (S100 and S110) which determine whether the internal combustion engine becomes stable after start of the internal combustion engine 1 or not; and back-flow delay calculation means (S120 and S130) which calculate back-flow delay until the return channel 38 is filled with the exhaust gas flowing therein based on the operating condition of the internal combustion engine 1 detected by the operating condition detection means, when the internal combustion engine after the start is determined to become stable by the start determination means (S100 and S110). Furthermore, the recirculation control device includes correction control means (S140 to S160) which control the adjustment means until the back-flow delay is dissolved to increase exhaust gas quantity to be recirculated.

Description

  The present invention relates to a recirculation control device for an internal combustion engine that controls exhaust gas recirculated through a recirculation flow path that connects an exhaust flow path and an intake flow path of the internal combustion engine. The present invention relates to a recirculation control device for an internal combustion engine that controls exhaust gas to be emitted.

  Conventionally, as a countermeasure for exhaust gas from internal combustion engines such as diesel engines and gasoline engines, in order to reduce the amount of nitrogen oxide (NOx) in the exhaust gas, a part of the exhaust gas is recirculated to the intake side. An exhaust gas recirculation device that keeps the combustion temperature low is used. With such an exhaust gas recirculation device, when the internal combustion engine is stopped, the combustion chamber and the like are filled with fresh air, and when the internal combustion engine is restarted, the recirculation flow path is fresh even if the exhaust gas is recirculated. Therefore, the exhaust gas recirculation effect is reduced.

  Also known are those with an idle stop function that improves fuel efficiency and reduces exhaust gas by stopping the operation of the internal combustion engine when stopping at a signal such as an intersection. In order to prevent an increase in combustion noise due to an excessive advance angle of the fuel injection timing in a state where the recirculation flow path is fresh at the time of restart due to, as described in Patent Document 1, the internal combustion engine is restarted after idle stop In this case, it is known that the fuel injection timing is retarded over a preset number of cycles until the exhaust gas flows into the combustion chamber via the recirculation flow path.

Japanese Patent No. 4313073

  However, in such a conventional system, combustion noise can be reduced by retarding the fuel injection timing after restart, and generation of nitrogen oxides can be reduced by retarding, but in order to reduce nitrogen oxides If the fuel injection timing is retarded too much, combustion may worsen and problems such as deterioration of idle vibration may occur, and exhaust gas flows into the intake passage before the preset number of cycles, or When exhaust gas flows into the intake passage after a preset number of cycles, there is a problem that the generation of nitrogen oxides is not reduced.

  The subject of this invention is providing the recirculation | reflux control apparatus of the internal combustion engine which can reduce more reliably generation | occurrence | production of nitrogen oxide at the time of start-up of an internal combustion engine.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
A recirculation flow path for recirculating exhaust gas by connecting an exhaust flow path and an intake flow path of the internal combustion engine, and an adjusting means for adjusting the amount of exhaust gas recirculated from the recirculation flow path to the intake flow path; In a recirculation control device for an internal combustion engine that controls exhaust gas recirculated to the intake flow path via the recirculation flow path,
An operating state detecting means for detecting an operating state of the internal combustion engine;
Start determination means for determining whether or not the engine is in a stable state after starting the internal combustion engine;
When it is determined by the start determination means that the engine is in a stable state after starting, until the recirculation flow path is filled with exhaust gas flowing in based on the operation state of the internal combustion engine detected by the operation state detection means A reflux delay calculating means for calculating the reflux delay of
This is a recirculation control device for an internal combustion engine, comprising correction control means for controlling the adjusting means until the recirculation delay is eliminated to increase the amount of exhaust gas to be recirculated.

  In this case, the start determination means may determine that the internal combustion engine is in a stable state after starting when the restart of the internal combustion engine is completed by an idling stop function. The adjusting means includes a reflux control valve interposed in the reflux flow path, an opening degree control valve provided on the exhaust gas inflow side of the supercharger, an exhaust throttle valve provided in the exhaust flow path, It may be at least one of throttle valves provided in the intake passage.

  The reflux delay calculating means may calculate the reflux delay from the volume of the reflux channel and the amount of exhaust gas flowing into the reflux channel calculated based on the operating state. Further, the correction control means may be configured to control the adjusting means in accordance with the recirculation delay and increase the exhaust gas amount as the recirculation delay increases. Alternatively, the correction control means may be configured to further reduce the fuel pressure until the reflux delay is eliminated. The correction control means may be configured to further increase the pilot injection amount until the reflux delay is eliminated.

  The recirculation control device for an internal combustion engine of the present invention increases the amount of exhaust gas passing through the recirculation flow path according to the recirculation delay calculated according to the operating state of the internal combustion engine when the internal combustion engine is in a stable state at the time of starting. Therefore, it is possible to accurately determine that the recirculation flow path is filled with the exhaust gas at an early stage, and that the recirculation flow path is filled with the exhaust gas, and shift to the normal fuel injection control. There is an effect that it can be reduced.

  When the start determination means completes the restart by the idling stop function, it can be determined that the engine is in a stable state by simple processing by determining that the engine is in a stable state after starting. The adjusting means is provided in the recirculation control valve interposed in the recirculation flow path, the opening control valve provided on the exhaust gas inflow side of the supercharger, the exhaust throttle valve provided in the exhaust flow path, and the intake flow path. By adjusting the amount of exhaust gas with at least one of the throttle valves, adjustment can be made with a simple configuration without adding a new valve.

  The reflux delay calculating means can accurately determine the reflux delay by calculating the reflux delay from the volume of the reflux channel and the amount of exhaust gas flowing into the reflux channel calculated based on the operating state. Nitrogen oxides in the exhaust gas can be further reduced by the correction control means reducing the fuel pressure and increasing the pilot injection amount.

1 is a schematic configuration diagram of an internal combustion engine using a recirculation control device for an internal combustion engine as one embodiment of the present invention. It is a block diagram which shows the electric system of the recirculation | reflux control apparatus of the internal combustion engine of this embodiment. It is a flowchart which shows an example of the recirculation | reflux control process at the time of starting performed in the electronic control circuit of this embodiment. It is a graph which shows the relationship between the reflux delay degree of this embodiment, and opening degree increase correction | amendment. It is a graph which shows the relationship between the reflux delay degree of this embodiment, and opening degree reduction correction | amendment. It is a flowchart which shows another example of the recirculation | reflux control process at the time of starting performed in the electronic control circuit of this embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail based on the drawings.
FIG. 1 is a schematic configuration diagram of an internal combustion engine using a recirculation control device for an internal combustion engine as an embodiment of the present invention. As shown in FIG. 1, the internal combustion engine 1 is a multi-cylinder, in this embodiment, for example, a 4-cylinder diesel engine, and a combustion chamber 8 is formed from a cylinder 2, a piston 4, and a cylinder head 6. The internal combustion engine 1 is not limited to a diesel engine, and can be implemented with a gasoline engine.

  The intake system of the internal combustion engine 1 includes an intake port 14 communicating with the combustion chamber 8 via an intake valve 12, an intake passage 16, a surge tank 18 that absorbs intake air pulsation, and a throttle valve 20 that adjusts the intake air amount. Is arranged. An air cleaner 22 is provided at the most upstream portion of the intake flow path 16, and an air flow sensor 24 is provided at the downstream side of the air cleaner 22.

  The intake passage 16 between the air flow sensor 24 and the throttle valve 20 is provided with a compressor 28 of the supercharger 26 and an intercooler 30 that cools the intake air pressurized by the compressor 28. Further, a fuel injection valve 31 for injecting fuel into the combustion chamber 8 is provided in the cylinder head 6.

  The exhaust system of the internal combustion engine 1 is provided with an exhaust port 34 and an exhaust passage 36 that communicate with the combustion chamber 8 via an exhaust valve 32. A recirculation flow path 38 that connects the intake flow path 16 and the exhaust flow path 36 is provided, and a recirculation control valve 40 is provided on the recirculation flow path 38 on the intake flow path 16 side.

  The recirculation flow path 38 is branched into an exhaust cooling flow path 42 and a bypass flow path 44 on the upstream side (exhaust flow path 36 side) of the recirculation control valve 40. An exhaust cooler 46 is interposed in the exhaust cooling flow path 42, and the exhaust cooler 46 is a well-known one that cools exhaust gas passing through the exhaust cooling flow path 42 with supplied cooling water. The bypass flow path 44 is provided to bypass the exhaust cooler 46, and the exhaust gas flowing through the bypass flow path 44 flows through the recirculation flow path 38 without passing through the exhaust cooler 46.

  A switching valve 48 is provided at a branch point where the exhaust cooling passage 42 and the bypass passage 44 branch. The switching valve 48 can switch the flow of exhaust gas between the exhaust cooling passage 42 and the bypass passage 44.

  An exhaust turbine 29 of the supercharger 26 is provided on the downstream side of the exhaust flow path 36 to which the recirculation flow path 38 is connected, and the supercharger 26 drives the exhaust turbine 29 with the exhaust gas to drive the compressor 28. And the intake air is supercharged.

  On the exhaust gas inflow side of the supercharger 26, an opening degree control valve 50 for adjusting the exhaust gas flowing into the exhaust turbine 29 is provided. An exhaust gas purification device 52 in which a catalyst, a diesel particulate filter, and the like are accommodated is interposed in the exhaust flow path 36 on the downstream side of the supercharger 26. An exhaust throttle valve 54 that can adjust the amount of exhaust gas in the exhaust passage 36 is provided in the exhaust passage 36 on the downstream side of the exhaust purification device 52.

  As shown in FIGS. 1 and 2, the detection system of the internal combustion engine 1 includes the air flow sensor 24, the throttle sensor 56 for detecting the opening degree of the throttle valve 20, and one rotation by two rotations of a crankshaft (not shown). A rotational speed sensor 58 that detects the rotational speed of the internal combustion engine 1 according to the rotation of a distributor shaft (not shown), an intake pressure sensor 60 that detects the intake pressure in the surge tank 18, and an intake air temperature in the intake passage 16. An intake air temperature sensor 62 and a cooling water temperature sensor 64 provided in the cylinder 2 for detecting the cooling water temperature are disposed.

  As shown in FIG. 2, each of the sensors is connected to an electronic control circuit 70. The electronic control circuit 70 is configured as a logical operation circuit centering on a well-known CPU 72, ROM 74, RAM 76, etc. An input circuit 78 to be performed and an output circuit 80 to be output to the outside are connected to each other via a common bus 82.

  The CPU 72 inputs input signals from the air flow sensor 24, the throttle sensor 56, the rotation speed sensor 58, the intake pressure sensor 60, the intake air temperature sensor 62, the cooling water temperature sensor 64, and the like via the input circuit 78, and these signals and the ROM 74. Based on the data in the RAM 76 and a control program stored in advance, the CPU 72 sends signals to the throttle valve 20, the reflux control valve 40, the switching valve 48, the opening control valve 50, the exhaust throttle valve 54, etc. via the output circuit 80. Is output.

Next, the start-up reflux control process performed in the electronic control circuit 70 described above will be described with reference to the flowchart of FIG.
The starting recirculation control process is repeatedly executed at regular intervals, and first, it is determined whether or not the starting of the internal combustion engine 1 has been completed (step 100; hereinafter referred to as S100, and so on). Whether or not the start is complete is determined based on the state of a starter (not shown), the rotational speed of the internal combustion engine 1 detected by the rotational speed sensor 58, and when it is determined that the start is not complete ( (S100: NO), this control process is temporarily terminated. When it is determined that the start has been completed (S100: YES), it is next determined whether or not the operation of the internal combustion engine 1 is in a stable state (S110).

  Whether or not the engine is in a stable state is determined based on the coolant temperature detected by the coolant temperature sensor 64, the rotational speed of the internal combustion engine 1 detected by the rotational speed sensor 58, and the like. If the cooling water temperature is equal to or higher than the predetermined temperature and the rotational speed is equal to or higher than the predetermined rotational speed, it can be determined that the internal combustion engine 1 is in a stable state in which continuous operation is possible without depending on the driving force of a starter (not shown).

  If it is determined that it is not in a stable state (S110: NO), this control process is once terminated. If it is determined that the engine is in a stable state (S110: YES), an estimate is made as to how long this control should continue based on the operating state of the internal combustion engine 1 (S120). The estimation is performed by calculating the degree of reflux delay, and is calculated by the following equation (1).

  In the equation (1), the EGR system volume is the volume of the return flow path 38 from the exhaust flow path 36 to the surge tank 18 of the intake flow path 16 and is determined by the configuration of the internal combustion engine 1 and is calculated and measured in advance. And memorized. The EGR flow rate is the exhaust gas flow rate that flows through the recirculation flow path 38 from the exhaust flow path 36 to the surge tank 18 side, and can be calculated by the following equation (2).

EGR flow rate = cylinder inflow air amount-air cleaner passage air amount (2)
Here, the cylinder inflow air amount is the operating state of the internal combustion engine 1 detected by the operating state detecting means, for example, the intake pressure detected by the intake pressure sensor 60, the rotational speed detected by the rotational speed sensor 58, and the intake air temperature. This is the amount of air that can be calculated as a function of the intake air temperature detected by the sensor 62 and is taken into the combustion chamber 8. The amount of air passing through the air cleaner is the amount of air that has passed through the air cleaner 22 detected by the air flow sensor 24.

  Since the amount of exhaust gas that has passed through the recirculation flow path 38 flows into the air cleaner passage air amount and flows into the combustion chamber 8, the EGR flow rate is calculated by the above equation (2), which is obtained by subtracting the air cleaner passage air amount from the cylinder inflow air amount. By integrating the EGR flow rate every time the control process is repeatedly executed, the exhaust gas flow rate (EGR flow rate) flowing into the reflux flow path 38 at each time can be calculated. By subtracting the exhaust gas flow rate (EGR flow rate) flowing into the reflux flow path 38 up to that time from the EGR system volume, it is possible to know the return delay of how far the exhaust gas has reached the reflux flow path 38. it can.

  When the internal combustion engine is stopped, the combustion chamber and the like are filled with fresh air, and when the internal combustion engine is started, the return flow path is filled with fresh air. Further, for example, when the internal combustion engine 1 is started, the internal combustion engine in which the air compressed by the supercharger 26 flows back from the intake flow channel 16 side to the exhaust flow channel 36 in order to warm the catalyst early. There is one.

  When the internal combustion engine 1 is started, the recirculation flow path 38 is filled with fresh air. When the internal combustion engine 1 is started and becomes stable, the recirculation flow path 38 is connected from the exhaust flow path 36 to the intake flow path 16 side. Exhaust gas flows in. The exhaust gas gradually flows through the recirculation flow path 38 from the exhaust flow path 36 side toward the intake flow path 16 side as time passes.

  By calculating and integrating the EGR flow rate of the above equation (2) every time this control process is repeatedly executed, it is possible to estimate the return delay of how much the exhaust gas flows into the return flow path 38 at that time. .

  In the present embodiment, as shown in the above equation (1), a reflux delay degree indicating a reflux delay is calculated as a ratio to the EGR system volume, and the reflux delay degree gradually changes from “1” to “0”. When the reflux delay degree is “1”, the reflux flow path 38 is filled with fresh air, and when it is “0”, the reflux flow path 38 is filled with exhaust gas.

  By calculating and updating the reflux delay degree every time this control process is repeatedly executed according to the above equation (1), it is possible to estimate how much the exhaust gas is flowing into the reflux flow path 38 at that time. In the present embodiment, the degree of reflux delay is calculated. However, the present invention is not limited to the case of calculating the degree of reflux. For example, the degree of reflux delay may be calculated only by the numerator of equation (1).

  After estimating the recirculation delay degree, next, the respective opening degrees of the recirculation control valve 40, the throttle valve 20, the opening degree control valve 50, and the exhaust throttle valve 54 are adjusted according to the recirculation delay degree. (S130).

  The correction of the opening degree of the recirculation control valve 40 is performed so that the opening degree of the recirculation control valve 40 increases as the recirculation delay degree increases as shown in FIG. When the opening degree of the reflux control valve 40 increases, the amount of exhaust gas passing through the reflux flow path 38 increases.

  Further, as shown in FIG. 5, the correction of the opening of the throttle valve 20, the opening control valve 50, and the exhaust throttle valve 54 is performed as the degree of reflux delay increases. It correct | amends so that each opening degree of 54 may reduce. As the respective openings of the throttle valve 20, the opening control valve 50, and the exhaust throttle valve 54 decrease, the amount of exhaust gas passing through the recirculation flow path 38 increases.

  When the opening degree of the throttle valve 20 is reduced, the intake passage 16 is throttled and the air pressure in the surge tank 18 is reduced, the pressure difference between the intake passage 16 side and the exhaust passage 36 side is increased, and the reflux flow is increased. The amount of exhaust gas passing through the path 38 increases.

  When the opening degree of the opening degree control valve 50 decreases, the amount of exhaust gas flowing into the exhaust turbine 29 of the supercharger 26 increases, and the flow path resistance of the exhaust flow path 36 increases. The amount of exhaust gas increases. When the opening degree of the exhaust throttle valve 54 decreases, the flow resistance of the exhaust flow path 36 increases, so that the amount of exhaust gas passing through the reflux flow path 38 increases.

  In the present embodiment, when the switching valve 48 is switched to the bypass flow path 44 side, the exhaust gas flows through the bypass flow path 44 and flows out to the intake flow path 16 side. The bypass channel 44 has a smaller channel resistance than the exhaust cooling channel 42, and the amount of exhaust gas passing through the reflux channel 38 is increased by switching the switching valve 48 to the bypass channel 44 side.

  Depending on the degree of reflux delay, the opening of the reflux control valve 40, throttle valve 20, opening control valve 50, and exhaust throttle valve 54 is corrected to increase the amount of exhaust gas passing through the reflux flow path 38, and The switching valve 48 is switched to increase the amount of exhaust gas passing through the reflux flow path 38. For example, each opening degree of the recirculation control valve 40, the throttle valve 20, the opening degree control valve 50, and the exhaust throttle valve 54 calculated by another control process (not shown) of the internal combustion engine 1 is corrected and passed through the recirculation flow path 38. Increase emissions. In the present embodiment, the recirculation control valve 40, the throttle valve 20, the opening degree control valve 50, and the exhaust throttle valve 54 constitute the adjusting means. However, the adjusting means includes the recirculation control valve 40, the throttle valve 20, and the opening degree. Any one of the control valve 50 and the exhaust throttle valve 54 may be used.

  Next, based on the degree of reflux delay, it is determined whether the reflux delay has been eliminated (S140). When the reflux delay degree calculated by executing the process of S120 is “0” or less, it is determined that the reflux delay has been eliminated. If the degree of reflux delay is not yet “0” or less, it is determined that the exhaust gas does not fill the recirculation flow path 38 and the exhaust gas has not reached the intake flow path 16 side.

  If it is determined that the reflux delay has not been eliminated (S140: NO), the correction of the opening degree by the process of S130 is continued, and the correction of reducing the fuel pressure of the common rail (not shown) and increasing the pilot injection amount is performed. (S150).

  When the fuel pressure of the common rail is reduced, the fuel injection pressure from the fuel injection valve 31 is reduced, the combustion temperature is lowered, and nitrogen oxides in the exhaust gas can be reduced. Further, when correction for increasing the pilot injection amount is performed, the main injection amount is reduced accordingly, the combustion temperature is lowered, and nitrogen oxides in the exhaust gas can be reduced. This correction is also performed by correcting the fuel pressure and pilot injection amount of the common rail calculated by another control process (not shown) of the internal combustion engine 1.

  While continuing the opening correction and correcting the decrease in the fuel pressure of the common rail and the increase in the pilot injection amount, this control process is repeatedly executed. Then, by executing the processing of S120, the reflux delay degree is calculated and updated to the estimated reflux delay degree. Then, according to the updated degree of recirculation delay, correction of the recirculation control valve 40, throttle valve 20, opening control valve 50, and exhaust throttle valve 54 is performed, and the switching valve 48 is connected to the bypass flow path 44 side. Switch to.

  If it is determined that the reflux delay has not been eliminated by the execution of the process of S140, this control process is repeatedly executed. If it is determined that the reflux delay has been eliminated (S140: YES), the reflux control valve 40, the throttle valve 20, The correction of the opening degree of the degree control valve 50 and the exhaust throttle valve 54 is stopped, and the switching of the switching valve 48 is stopped (S160), and this control process is temporarily ended.

  In the present embodiment, control is performed to retard the fuel injection timing until it is determined in S140 that the return delay has been eliminated after it is determined that the engine is in the stable state after the start in S110. . By retarding, the generation of nitrogen oxides can be reduced.

  In this embodiment, the execution of the processes of S100 and S110 functions as a start determination unit, the execution of the processes of S120 and S130 functions as a reflux delay calculation unit, and the execution of the processes of S140 to S160 serves as a correction control unit. work.

  In this way, when the internal combustion engine 1 is in a stable state when the internal combustion engine 1 is started, the reflux delay degree is estimated according to the operation state of the internal combustion engine 1, and the reflux control is performed according to the reflux delay degree. The opening of the valve 40, the throttle valve 20, the opening control valve 50, and the exhaust throttle valve 54 is corrected to increase the amount of exhaust gas passing through the recirculation flow path 38, and the switching valve 48 is switched to recirculate. The amount of exhaust gas passing through the flow path 38 is increased. Further, correction is performed to reduce the fuel pressure of the common rail and increase the pilot injection amount to reduce nitrogen oxide in the exhaust gas.

  When the reflux delay is resolved, each correction is stopped. When the reflux delay is eliminated, the reflux passage 38 is filled with the exhaust gas, and when the reflux delay is eliminated, the exhaust gas reflux rate (not shown) is determined based on the rotational speed, the injection amount, and the like of the internal combustion engine 1. The exhaust gas recirculation rate is calculated from the map, and the recirculation control valve 40 is controlled based on the exhaust gas recirculation rate to adjust the amount of exhaust gas recirculated from the recirculation flow path 38 to the intake flow path 16. Can be started appropriately, the combustion temperature of the internal combustion engine 1 can be lowered, and the generation of nitrogen oxides can be suppressed.

  Next, a recirculation control device for an internal combustion engine according to a second embodiment will be described with reference to the flowchart of FIG. The same processes as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the second embodiment, whether or not the internal combustion engine 1 is in a stable state in the processing of S110 of the above-described embodiment is determined based on whether or not the internal combustion engine 1 has been restarted by the idling stop function (ISS) (S110a). ). Since the idling stop function (ISS) is performed only in a stable state such as after the internal combustion engine 1 is warmed up, it can be determined that the internal combustion engine 1 is in a stable state when the internal combustion engine 1 is restarted by the idling stop function (ISS). Thereby, it is not necessary to detect and judge the operating state of the internal combustion engine 1, and the processing becomes easy.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder 4 ... Piston 6 ... Cylinder head 8 ... Combustion chamber 12 ... Intake valve 14 ... Intake port 16 ... Intake passage 18 ... Surge tank 20 ... Throttle valve 22 ... Air cleaner 24 ... Air flow sensor 26 ... Supercharging Machine 30 ... Intercooler 31 ... Fuel injection valve 32 ... Exhaust valve 34 ... Exhaust port 36 ... Exhaust flow path 38 ... Recirculation flow path 40 ... Recirculation control valve 42 ... Exhaust cooling flow path 44 ... Bypass flow path 46 ... Exhaust cooler 48 ... Switch valve 50 ... Opening control valve 52 ... Exhaust gas purification device 54 ... Exhaust throttle valve 56 ... Throttle sensor 58 ... Revolution sensor 60 ... Intake pressure sensor 62 ... Intake temperature sensor 64 ... Cooling water temperature sensor 70 ... Electronic control circuit

Claims (7)

A recirculation flow path for recirculating exhaust gas by connecting an exhaust flow path and an intake flow path of the internal combustion engine, and an adjusting means for adjusting the amount of exhaust gas recirculated from the recirculation flow path to the intake flow path; In a recirculation control device for an internal combustion engine that controls exhaust gas recirculated to the intake flow path via the recirculation flow path,
An operating state detecting means for detecting an operating state of the internal combustion engine;
Start determination means for determining whether or not the engine is in a stable state after starting the internal combustion engine;
When it is determined by the start determination means that the engine is in a stable state after starting, until the recirculation flow path is filled with exhaust gas flowing in based on the operation state of the internal combustion engine detected by the operation state detection means A reflux delay calculating means for calculating the reflux delay of
A recirculation control apparatus for an internal combustion engine, comprising: correction control means for increasing the amount of exhaust gas to be recirculated by controlling the adjusting means until the recirculation delay is eliminated. 2. The internal combustion engine according to claim 1, wherein the start determination unit determines that the internal combustion engine is in a stable state after starting when the restart of the internal combustion engine is completed by an idling stop function. Reflux control device. The adjusting means includes a recirculation control valve interposed in the recirculation flow path, an opening degree control valve provided on the exhaust gas inflow side of the supercharger, an exhaust throttle valve provided in the exhaust flow path, the intake flow The recirculation control apparatus for an internal combustion engine according to claim 1 or 2, wherein the recirculation control apparatus is at least one of throttle valves provided on the road. The recirculation delay calculation means calculates a recirculation delay from the volume of the recirculation flow path and the amount of exhaust gas flowing into the recirculation flow path calculated based on the operating state. 4. The internal combustion engine reflux control device according to any one of 3 above. The correction control means controls the adjusting means according to the reflux delay, and increases the exhaust gas amount as the reflux delay is larger. The internal combustion engine reflux control device according to claim 1. 6. The recirculation control device for an internal combustion engine according to claim 1, wherein the correction control means further reduces the fuel pressure until the recirculation delay is eliminated. The internal combustion engine recirculation control apparatus according to any one of claims 1 to 6, wherein the correction control means further increases the pilot injection amount until the recirculation delay is eliminated.

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