JP2019065821A - Control device of internal combustion engine - Google Patents

Abstract

To provide a technology which can accurately diagnose the adhesion or accumulation of deposits to an intake valve and a throttle valve at a low cost.SOLUTION: It is determined whether or not a throttle opening TA is larger than an opening TA1 (S10). When a determination result of the step S10 is affirmative, it is determined whether or not Pmr-Pme>H1 is satisfied (S12). When a determination result of the step S12 is affirmative, an intake valve map Mi is corrected (S14). When the determination result of the step S10 is non-affirmative, it is determined whether or not a correction completion flag of the intake valve map Mi is turned on (S20). When a determination result of the step S20 is affirmative, it is determined whether or not Pmr-Pme>TH2 is satisfied (S22). When a determination result of the step S22 is affirmative, a throttle valve map Mt is corrected (S24).SELECTED DRAWING: Figure 5

Description

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

  It is known that deposits adhere or accumulate on an intake valve, a throttle valve, and an inner wall of an intake pipe in the vicinity thereof, which are intake system components of an internal combustion engine. Deposits are derived from lubricating oil components and combustion products. If deposits adhere to or accumulate on the intake system components, the intake characteristics of the internal combustion engine will change over time, which will adversely affect fuel injection control and the like. Therefore, it is important to diagnose the deposition or deposition of the deposit and to take appropriate measures according to the diagnostic result.

  Japanese Patent Laid-Open No. 2006-312890 discloses an apparatus for diagnosing deposition of deposits using detection values of an air flow meter, an intake pipe pressure sensor, and a throttle opening degree sensor during idle operation. This conventional diagnostic device diagnoses that deposits are accumulated on the intake valve when the detected value of intake air amount does not change with time, while the detected value of intake pipe pressure increases with time. . Further, in this conventional diagnostic device, when the detected values of the intake air amount and the intake pipe pressure do not change with time, and when the detected values of the throttle opening change with time, deposits accumulate on the throttle valve. To diagnose.

JP, 2006-312890, A JP 2008-014179 A JP, 2009-293515, A

  Although not mentioned in Japanese Patent Laid-Open No. 2006-312890, in idle operation, it is general to adjust the opening degree of the throttle valve in order to keep the intake air amount constant. In idle operation, for example, when the amount of intake air decreases, the degree of opening of the throttle valve is adjusted to the open side so as to compensate for this decrease. When the opening degree of the throttle valve is adjusted to the open side, the intake pipe pressure rises.

  If deposits accumulate on the intake valve, the amount of intake air decreases. Therefore, according to the idle operation, when deposits are accumulated on the intake valve, the intake pipe pressure is increased. Therefore, the detection value of the intake pipe pressure during idle operation will increase with time. However, even if deposits are accumulated on the throttle valve, the amount of intake air decreases. Therefore, according to the idle operation, even when deposits are accumulated on the throttle valve, the detected value of the intake pipe pressure during the idle operation will increase with time.

  The above-mentioned conventional diagnostic device does not change with time in the detected value of the intake air amount, and on the other hand, when the detected value of the intake pipe pressure increases with time, it diagnoses that deposits are accumulated on the intake valve. Therefore, even if deposits are accumulated on both the intake valve and the throttle valve, the above-described conventional diagnostic device diagnoses that the deposits are accumulated on the intake valve. As described above, in consideration of the adjustment of the opening of the throttle valve in the idle operation, the above-described conventional diagnostic device can not diagnose that deposits are accumulated on both valves.

  Further, the above-described conventional diagnostic device diagnoses the deposition of deposits based on the temporal change of the detected value of the intake pipe pressure. Therefore, depending on the altitude at the time of diagnosis, there is a possibility that the diagnosis of deposit may be mistaken due to the influence of atmospheric pressure. For example, if deposits are accumulated on the intake valve during movement to the high ground after the first diagnosis at low ground, no change in detected value over time is found in the second diagnosis at high ground where the intake pipe pressure decreases there is a possibility. As a result, it is misdiagnosed that deposits have not accumulated on the intake valve. In addition, if deposits are accumulated on the throttle valve during movement to the low ground after the first diagnosis at high ground, the detection value may increase over time in the second diagnosis on the low ground where the intake pipe pressure rises. There is. As a result, it is misdiagnosed that deposits have accumulated on the intake valve.

  Further, the above-described conventional diagnostic device performs diagnosis using detection values of an air flow meter, an intake pipe pressure sensor, and a throttle opening degree sensor. Therefore, there is room for improvement also in terms of the cost of these on-vehicle sensors.

  The present invention has been made in view of at least one of the above-described problems, and provides a technology capable of realizing diagnosis of adhesion or deposition of deposits on the intake valve and the throttle valve with high accuracy and at low cost. The purpose is to

The present invention is a control device for an internal combustion engine to achieve the above object, and has the following features.
The internal combustion engine includes an intake valve, a throttle valve, an intake pipe pressure sensor, a throttle opening degree sensor, and a rotational speed sensor. The intake pipe pressure sensor detects an actual intake pipe pressure downstream of the throttle valve. The throttle opening degree sensor detects an actual opening degree of the throttle valve. The rotational speed sensor detects an actual rotational speed of the internal combustion engine.
The control device is configured to control the internal combustion engine using an intake valve map and a throttle valve map. The intake valve map is a map that defines the relationship between the amount of air passing through the intake valve and the intake pipe pressure downstream of the throttle valve. The throttle valve map is a map that defines the relationship between the amount of air passing through the throttle valve and the intake pipe pressure downstream of the throttle valve.
The control device includes an intake valve determination unit. The intake valve determination unit determines whether deposits adhere or accumulate on the intake valve when the actual opening degree is larger than a predetermined value. The intake valve determination unit calculates a first pressure difference calculated by subtracting the first estimated intake pipe pressure estimated using the actual rotation speed and the actual opening degree from the actual intake pipe pressure from the first determination value. If the value is too large, it is determined that deposits are attached or accumulated on the intake valve.
The control device includes an intake valve map correction unit. The intake valve map correction unit corrects the intake valve map when it is determined that deposits adhere or accumulate on the intake valve. The intake valve map correction unit corrects the intake valve map by learning using a difference between the first air amount and the second air amount. The first air amount is calculated by applying the first estimated intake pipe pressure to the intake valve map. The second air amount is calculated by applying the actual intake pipe pressure to the throttle valve map.
The control device includes a throttle valve determination unit. The throttle valve determination unit determines whether or not deposits adhere or deposit on the throttle valve when a predetermined condition regarding correction of the intake valve map is satisfied and the actual opening degree is smaller than the predetermined value. Determine if The throttle valve determination unit calculates a second pressure difference calculated by subtracting the actual intake pipe pressure from a second estimated intake pipe pressure estimated from the actual rotational speed and the actual opening degree from a second determination value. If it is too large, it is determined that deposits are deposited or accumulated on the throttle valve.
The controller includes a throttle valve map correction unit. The throttle valve map correction unit corrects the throttle valve map when it is determined that deposits are deposited or accumulated on the throttle valve. The throttle valve map correction unit is configured to calculate the third amount of air calculated by applying the second estimated intake pipe pressure to the throttle valve, and the actual intake to the latest intake valve map after the establishment of the predetermined condition. The throttle valve map is corrected by learning using the difference between the fourth air amount calculated by applying the tube pressure and the fourth air amount.

  According to the present invention, when the actual opening degree of the throttle valve is larger than a predetermined value, it is determined whether the deposit adheres or deposits on the intake valve. If the actual opening degree of the throttle valve is large to a certain extent, even if deposits adhere to or accumulate on the throttle valve, the influence of the deposits on the actual intake pipe pressure decreases. Therefore, by setting the predetermined value to an appropriate value, it is possible to determine with high accuracy whether or not the deposit is attached to or accumulated in the intake valve by eliminating the influence of the deposit attached or accumulated on the throttle valve.

  Further, according to the present invention, after the predetermined condition for correcting the intake valve map is satisfied, when the actual opening degree of the throttle valve is smaller than a predetermined value, it is determined whether deposit adheres or deposits on the throttle valve. Is done. After the predetermined condition is established, it is at least determined whether deposit of the intake valve is attached or accumulated, and depending on the determination result, correction of the intake valve map is performed. Therefore, it is possible to determine with high accuracy whether or not the deposit is adhered to or accumulated in the throttle valve, taking into consideration only the influence on the actual intake pipe pressure by the deposit adhered to or accumulated in the throttle valve. As described above, according to the present invention, it can be determined with high accuracy that deposits adhere or accumulate on both the intake valve and the throttle valve.

  In the above-described conventional diagnostic device, the diagnosis of whether deposits are accumulated on the intake valve or the throttle valve is performed based on the temporal change of the detected value of the intake pipe pressure. On the other hand, in the present invention, it is determined whether deposits adhere or deposit on the intake valve or the throttle valve using the detection values of the rotational speed sensor, the intake pipe pressure sensor, and the throttle opening sensor. That is, in the present invention, the above determination can be performed without being based on the temporal change of the detected value of the intake pipe pressure. Therefore, according to the present invention, the above determination can be performed regardless of the altitude at the time of diagnosis.

  In the above-mentioned conventional diagnostic device, the diagnosis of whether deposits are accumulated on the intake valve or the throttle valve is performed using the detection values of the air flow meter, the intake pipe pressure sensor and the throttle opening degree sensor. On the other hand, in the present invention, it is determined whether deposits adhere or deposit on the intake valve or the throttle valve using the detection values of the rotational speed sensor, the intake pipe pressure sensor, and the throttle opening sensor. That is, in the present invention, the above-described conventional diagnostic device can perform the above determination without using the detection value of the air flow meter required. Therefore, according to the present invention, it is possible to remove the air flow meter from the vehicle and reduce the total number of on-board sensors, thereby reducing the cost of on-board sensors.

It is a schematic diagram explaining composition of a system concerning Embodiment 1 of the present invention. FIG. 6 is a view for explaining an example of an intake valve characteristic representing the relationship between an air amount mi and an intake pipe pressure Pm, and an example of a throttle valve characteristic representing the relationship between the air amount mi and the intake pipe pressure Pm. It is a figure explaining the correction method of intake valve map Mi. It is a figure explaining the correction method of throttle valve map Mt. It is the flowchart which showed an example of the processing routine which ECU performs in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[Description of system configuration]
FIG. 1 is a schematic diagram for explaining the configuration of a system according to Embodiment 1 of the present invention. The system shown in FIG. 1 includes an internal combustion engine (hereinafter also referred to as "engine") 10 mounted on a vehicle. The engine 10 is a spark ignition engine. The number of cylinders of the engine 10 and the cylinder arrangement are not particularly limited. Each cylinder of the engine 10 is provided with a combustion chamber 12. A spark plug 14 of an igniter is attached to the top of the combustion chamber 12. The piston 16 of the engine 10 is connected to the crankshaft 20 via a connecting rod 18. The crankshaft 20 is provided with a crank angle sensor 42 used to measure the engine rotational speed NE.

  An intake port 22 is in communication with the combustion chamber 12. The intake port 22 is provided with an intake valve 24 for opening and closing the intake port 22. The intake port 22 is also provided with a port injector 26 for injecting fuel into the intake port 22. Although only the port injector 26 is disclosed in FIG. 1, an in-cylinder injector that directly injects fuel into the combustion chamber 12 may be provided in the combustion chamber 12 instead of the port injector 26. Both the port injector 26 and the in-cylinder injector may be provided in the combustion chamber 12.

  An intake manifold 28 in which a surge tank is integrated is connected to the intake port 22. An intake pipe pressure sensor 44 for measuring an intake pipe pressure Pm is attached to the intake manifold 28. An intake pipe 30 that sucks in air from the outside is connected to the intake manifold 28. In the vicinity of the intake manifold 28 in the intake pipe 30, an electronically controlled throttle valve 32 is provided. In the vicinity of the throttle valve 32, a throttle opening degree sensor 46 for detecting the throttle opening degree TA is attached.

  The system shown in FIG. 1 includes an ECU (Electronic Control Unit) 40 as a control device. The ECU 40 includes an input / output interface, a memory, and an arithmetic processing unit (CPU). The input / output interface is provided to take in sensor signals from various sensors attached to the engine 10 or the vehicle and to output operation signals to various actuators for controlling the engine 10. The memory stores various control programs for controlling the engine 10, maps, and the like. The CPU reads out and executes a control program and the like from the memory, and generates operation signals of various actuators based on the acquired sensor signal.

[Description of fuel injection control]
The control of the engine 10 performed by the ECU 40 includes fuel injection control of the port injector 26. In the fuel injection control, the ECU 40 estimates the intake air amount Ga based on the intake valve map Mi or the throttle valve map Mt and the actual intake pipe pressure Pmr. Further, the ECU 40 calculates the fuel injection amount tau from the port injector 26 based on the estimated intake air amount Ga. The intake valve map Mi is a map that defines the relationship between the amount of air passing through the intake valve 24 (that is, the amount of air taken into the cylinder) mi and the intake pipe pressure Pm. The throttle valve map Mt is a map that defines the relationship between the amount of air mt passing through the throttle valve 32 and the intake pipe pressure Pm.

  FIG. 2 is a view for explaining an example of an intake valve characteristic representing the relationship between the air amount mi and the intake pipe pressure Pm and an example of a throttle valve characteristic representing the relationship between the air amount mi and the intake pipe pressure Pm. . From the intake valve characteristics shown in FIG. 2, it can be seen that the air amount mi increases as the intake pipe pressure Pm increases. The intake valve map Mi is created based on such an intake valve characteristic. From the throttle valve characteristics shown in FIG. 2, when the intake pipe pressure Pm is lower than a certain pressure value, the air quantity mt is constant, and when the intake pipe pressure Pm is higher than this pressure value, the intake pipe pressure Pm is It can be seen that the air amount mi decreases as the value increases. The throttle valve map Mt is created based on such throttle valve characteristics.

  When the operating state of the engine 10 is steady, the air amount mi obtained from the intake valve map Mi matches the air amount mt obtained from the throttle valve map Mt. The intersection of the intake valve characteristic and the throttle valve characteristic shown in FIG. 2 represents this coincident point. When the operating state of the engine 10 is steady, for example, when the rate of change of the throttle opening degree TA is approximately constant, the air amount mi obtained from the intake valve map Mi or the air amount mt determined using the throttle valve map Mt Is the intake air amount Ga. On the other hand, when the operating state of the engine 10 is not steady, for example, when the rate of change is not constant, the air amount mt is also not constant. Therefore, in this case, the amount of air mi obtained from the intake valve map Mi is the amount of intake air Ga.

[Correction of intake valve map Mi and throttle valve map Mt]
1. Problems when deposit adheres to or deposits on the intake valve 24 or the throttle valve 32 Deposits or deposits on the intake valve 24 cause aging in the intake valve characteristics. Similarly, if deposits adhere to or accumulate on the throttle valve 32, the throttle valve characteristics change with time. When temporal changes occur in these characteristics, the estimation accuracy of the intake air amount Ga determined based on the intake valve map Mi or the throttle valve map Mt and the actual intake pipe pressure Pmr decreases. Then, the calculation accuracy of the fuel injection amount tau decreases, and the emission and the drivability deteriorate.

2. Therefore, in the present embodiment, the ECU 40 determines whether deposits adhere or deposit on the intake valve 24 or the throttle valve 32 (hereinafter, also referred to as "deposit determination"). . However, deposits may adhere to or accumulate on both the intake valve 24 and the throttle valve 32. Therefore, in the present embodiment, first, deposit determination is performed on the intake valve 24. The deposit determination of the intake valve 24 is performed for the following reason. That is, when deposits adhere to or accumulate on the intake valve 24, the intake pipe pressure Pm increases and the air amount mt and the air amount mi decrease even if the throttle opening degree TA is constant. However, even if deposits adhere to or accumulate on the throttle valve 32, the air amount mt does not change if the throttle opening degree TA is large to a certain extent. As described above, if the condition of the throttle opening degree TA is satisfied, it is possible to investigate only the influence of the intake valve 24 on the intake valve characteristic by ignoring the influence on the intake valve characteristic by the deposit attached to or accumulated on the throttle valve 32. .

For the above reasons, in the present embodiment, the deposit determination of the intake valve 24 is performed first. When the throttle opening degree TA is larger than the predetermined opening degree TA1 (provided that the operating state of the engine 10 is steady), the ECU 40 makes a deposit determination on the intake valve 24. The deposit determination of the intake valve 24 is performed based on whether the relationship between the actual intake pipe pressure Pmr and the estimated intake pipe pressure Pme satisfies the condition of the following formula (1).
Pmr-Pme> threshold TH1 (1)
The estimated intake pipe pressure Pme is an estimated value of the intake pipe pressure Pm calculated using a physical model or an empirical formula model with the throttle opening degree TA and the engine rotational speed NE as variables.

3. When the condition of the correction formula (1) of the intake valve map Mi is satisfied, the ECU 40 determines that the deposit is attached or accumulated on the intake valve 24. If it is determined that the deposit adheres to or deposits on the intake valve 24, the ECU 40 learns that the air amount mi is decreased due to the deposit. That is, the ECU 40 learns the temporal change of the intake valve characteristic. FIG. 3 is a diagram for explaining a method of correcting the intake valve map Mi. In the present embodiment, temporal change in intake valve characteristics is learned using the difference Dmi between the estimated air amount mie and the actual air amount mtr shown in FIG. The estimated air amount mie is calculated based on the latest intake valve map Mi and the estimated intake pipe pressure Pme. The actual air amount mtr is calculated based on the latest throttle valve map Mt and the actual intake pipe pressure Pmr.

  For convenience of explanation, in the following, the latest intake valve map Mi is referred to as an intake valve map Mi (k) with reference to the number k of deposit determinations of the intake valve 24 performed before the deposit determination of this intake valve 24 this time. It is also called. Further, the latest throttle valve map Mt is also referred to as a throttle valve map Mt (k).

  When deposits adhere to or accumulate on the intake valve 24, the data value of the air amount mi constituting the intake valve map Mi (k) indicates a value smaller than the true air amount mi. However, as described above, when the operating state of the engine 10 is steady, the air amount mi obtained from the intake valve map Mi matches the air amount mt obtained from the throttle valve map Mt. Therefore, it is estimated that the actual air amount mtr obtained from the throttle valve map Mt (k) is close to the true air amount mi. Under this assumption, in the present embodiment, the difference Dmi is calculated. If the throttle opening degree TA or the engine rotational speed NE changes, the estimated intake pipe pressure Pme also changes. Therefore, the ECU 40 calculates the difference Dmi each time the throttle opening degree TA or the engine rotational speed NE changes. The estimated intake pipe pressure Pme when the throttle opening degree TA is smaller than the opening degree TA1 is estimated using the calculated difference Dmi.

  After calculation or estimation of the difference Dmi, the ECU 40 uses the difference Dmi to correct the data value of the air amount mi constituting the intake valve map Mi (k). The broken line shown in FIG. 3 represents the relationship between the data value of the air amount mi constituting the corrected intake valve map Mi (k) and the intake pipe pressure Pm, that is, the intake valve characteristics after learning of the change over time is completed. It represents.

4. Determination of Deposit of Throttle Valve 32 After the processing regarding correction of the data value of the air amount mi constituting the intake valve map Mi (k) is completed, the ECU 40 determines that the throttle opening degree TA is smaller than the opening degree TA1 (however, The operating condition of the engine 10 is assumed to be steady), and the deposit determination of the throttle valve 32 is performed. The deposit determination of the throttle valve 32 is performed based on whether or not the relationship between the actual intake pipe pressure Pmr and the estimated intake pipe pressure Pme satisfies the condition of the following formula (2).
Pme−Pmr> threshold TH2 (2)

  Here, there are two reasons that the process regarding correction of the data value of the air amount mi is completed. The first reason is that the data value of the air amount mi may not be corrected depending on the result of the deposit determination of the intake valve 24. That is, when it is determined that the deposit does not adhere or deposit on the intake valve 24, the ECU 40 determines that "the process related to the correction of the data value of the air amount mi is completed" based on the determination result. The second reason is that it takes time to complete the correction of the data value of the air amount mi in the entire range of the engine rotational speed. That is, when the correction of the region NE1 (for example, a region near 1000 rpm) of the engine rotational speed NE is completed, the ECU 40 “data value of the air amount mi even if the correction of another region NE2 (for example a region near 2000 rpm) is not completed It is determined that the processing for the correction of has been completed. Then, with respect to the area NE2, while continuing the processing relating to the correction, the process proceeds to the deposit determination of the throttle valve 32 for the area NE1.

5. When the condition of the correction formula (2) of the throttle valve map Mt is satisfied, the ECU 40 determines that the deposit is attached or accumulated on the throttle valve 32. When it is determined that the deposit adheres to or accumulates on the throttle valve 32, the ECU 40 learns that the air amount mt is decreased due to the deposit. That is, the ECU 40 learns the change over time of the throttle valve characteristic. FIG. 4 is a diagram for explaining a method of correcting the throttle valve map Mt. In the present embodiment, the temporal change of the throttle valve characteristic is learned using the difference Dmt between the estimated air amount mte and the actual air amount mir shown in FIG. The estimated air amount mte is calculated based on the throttle valve map Mt (k) and the estimated intake pipe pressure Pme. The actual air amount mir is calculated based on the corrected intake valve map Mi (k) and the actual intake pipe pressure Pmr.

  When deposits adhere to or accumulate on the throttle valve 32, the data value of the air amount mt constituting the throttle valve map Mt (k) indicates a value smaller than the true air amount mt. However, as described above, when the operating state of the engine 10 is steady, the air amount mi obtained from the intake valve map Mi matches the air amount mt obtained from the throttle valve map Mt. Further, the intake valve map Mi is corrected by the process described above. Therefore, it is estimated that the actual air amount mir obtained from the corrected intake valve map Mi (k) is close to the true air amount mt. Under this assumption, in the present embodiment, the difference Dmt is calculated. If the throttle opening degree TA or the engine rotational speed NE changes, the estimated intake pipe pressure Pme also changes. Therefore, the ECU 40 calculates the difference Dmt each time the throttle opening degree TA or the engine rotational speed NE changes. The estimated intake pipe pressure Pme when the throttle opening degree TA is larger than the opening degree TA1 is estimated using the calculated difference Dmt.

  After calculating or estimating the difference Dmt, the ECU 40 uses the difference Dmt to correct the data value of the air amount mt that constitutes the throttle valve map Mt (k). The broken line shown in FIG. 4 indicates the relationship between the data value of the air amount mt constituting the corrected throttle valve map Mt (k) and the intake pipe pressure Pm, that is, the throttle valve characteristics after learning of the change over time is completed. It represents.

  After the process related to the correction of the data value of the air amount mt constituting the throttle valve map Mt (k) is completed, the ECU 40 proceeds to the k + 1st deposit determination of the intake valve 24. The reason why the process for correcting the data value of the air amount mt has been completed is basically the same as the reason that the process for correcting the data value of the air amount mi is completed. .

[Specific processing]
FIG. 5 is a flowchart showing an example of a processing routine performed by the ECU 40 to realize the above-described function in the present embodiment. The processing routine shown in the figure is repeatedly executed at a predetermined control cycle.

  In the processing routine shown in FIG. 5, the ECU 40 first determines whether the throttle opening degree TA is larger than the opening degree TA1 (step S10). If the determination result of this step is affirmative, the ECU 40 proceeds to the process of step S12. If the determination result of this step is negative, the ECU 40 proceeds to the process of step S20.

  In step S12, the ECU 40 determines whether Pmr-Pme> TH1 is satisfied. That is, the ECU 40 determines whether the condition of the equation (1) is established as the deposit determination of the intake valve 24. When the condition of the equation (1) is satisfied, the ECU 40 determines that the deposit adheres or deposits on the intake valve 24, and proceeds to the process of step S14. When the condition of the equation (1) is not satisfied, the ECU 40 determines that the deposit does not adhere or deposit on the intake valve 24, and proceeds to the process of step S18.

  In step S14, the ECU 40 corrects the intake valve map Mi. The method of correcting the intake valve map Mi is as described in FIG.

  Subsequently to step S14, the ECU 40 determines whether or not the process regarding the correction of the data value of the air amount mi is completed in a predetermined engine rotational speed region (step S16). The predetermined engine rotational speed region is set, for example, by dividing the entire region of the engine rotational speed at predetermined intervals. In order to perform the process related to the correction of the data value of the air amount mi in the entire region of the engine rotational speed, the processing routine shown in the figure may be provided as many as the number of areas after division at predetermined intervals. If the determination result of this step is affirmative, the ECU 40 proceeds to the process of step S18. If the determination result of this step is negative, the ECU 40 returns to the process of step S10.

  In step S18, the ECU 40 sets the correction completion flag of the intake valve map Mi to ON. Then, the ECU 40 returns to the process of step S10.

  In step S20, the ECU 40 determines whether the correction completion flag of the intake valve map Mi is set to ON. If the determination result of this step is affirmative, the ECU 40 proceeds to the process of step S22. If the determination result of this step is negative, the ECU 40 returns to the process of step S10.

  In step S22, the ECU 40 determines whether Pme-Pmr> TH2 is satisfied. That is, the ECU 40 determines whether the condition of the equation (2) is satisfied as the deposit determination of the throttle valve 32. When the condition of the equation (2) is satisfied, the ECU 40 determines that the deposit is attached or accumulated on the throttle valve 32, and proceeds to the process of step S24. When the condition of the equation (2) is not satisfied, the ECU 40 determines that the deposit does not adhere or deposit on the throttle valve 32, and proceeds to the process of step S28.

  In step S24, the ECU 40 corrects the throttle valve map Mt. The correction method of the throttle valve map Mt is as described in FIG.

  Subsequently to step S24, the ECU 40 determines whether or not the process related to the correction of the data value of the air amount mt is completed in a predetermined engine rotational speed region (step S26). The predetermined engine rotational speed area is the same as the area used in the process of step S16. If the determination result of this step is affirmative, the ECU 40 proceeds to the process of step S28. If the determination result of this step is negative, the ECU 40 returns to the process of step S10.

  In step S28, the ECU 40 sets the correction completion flag of the intake valve map Mi to OFF, and exits the processing routine.

  According to the processing routine of FIG. 5 described above, the intake valve map Mi and the throttle valve map Mt can be corrected in a predetermined engine rotational speed region. Therefore, it is possible to suppress a decrease in the estimation accuracy of the intake air amount Ga obtained based on the intake valve map Mi or the throttle valve map Mt. Therefore, the calculation accuracy of the fuel injection amount tau is lowered, and deterioration of the emission and the drivability can be suppressed.

In the above embodiment, the “intake valve determination unit” of the present invention is realized by the ECU 40 executing the processes of steps S10 and S12. Further, the difference between the actual intake pipe pressure Pmr and the estimated intake pipe pressure Pme used in the process of step S12 corresponds to the "first pressure value" of the present invention, and the threshold TH1 is the "first determination value" of the present invention. Equivalent to.
Further, the “intake valve map correction unit” of the present invention is realized by the ECU 40 executing the process of step S14. Further, the estimated air amount mie used in the process of step S14 corresponds to the "first air amount" of the present invention, and the actual air amount mtr corresponds to the "second air amount" of the present invention.
Further, the "throttle valve determination unit" of the present invention is realized by the ECU 40 executing the processing of steps S20 and S22. When it is determined in step S20 that the correction completion flag of the intake valve map Mi is set to ON, the "predetermined condition regarding correction of the intake valve map" of the present invention is satisfied. The difference between the estimated intake pipe pressure Pme and the actual intake pipe pressure Pmr used in the process of step S22 corresponds to the “second pressure value” in the present invention, and the threshold TH2 corresponds to the “second determination value” in the present invention. .
Further, the "throttle valve map correction unit" of the present invention is realized by the ECU 40 executing the processing of step S24. Further, the estimated air amount mte used in the process of step S24 corresponds to the "third air amount" of the present invention, and the actual air amount mir corresponds to the "fourth air amount" of the present invention.

  In addition, when the number of the number, the quantity, the quantity, the range, etc. of each element is mentioned in the above embodiment, the case is mentioned except in the case where it is particularly clearly indicated or the case where the number is clearly specified in principle. The invention is not limited to a number. Further, the structures and the like described in this embodiment are not necessarily essential to the present invention, unless otherwise specified or clearly specified in principle.

10 internal combustion engine 24 intake valve 32 throttle valve 40 ECU
42 crank angle sensor 44 intake pipe pressure sensor 46 throttle opening sensor Mi intake valve map Mt throttle valve map mie, mte estimated air amount mir, mtr actual air amount Pme estimated intake pipe pressure Pmr actual intake pipe pressure

Claims (1)

A control device for an internal combustion engine,
The internal combustion engine includes an intake valve, a throttle valve, an intake pipe pressure sensor that detects an actual intake pipe pressure downstream of the throttle valve, and a throttle opening degree sensor that detects an actual opening degree of the throttle valve. A rotational speed sensor for detecting an actual rotational speed of the internal combustion engine;
The control device is an air estimated using an actual intake pipe pressure and an intake valve map that defines a relationship between an amount of air passing through the intake valve and an intake pipe pressure downstream of the throttle valve. Or an amount of air estimated using the actual intake pipe pressure and a throttle valve map that defines the relationship between the amount or the amount of air passing through the throttle valve and the intake pipe pressure downstream of the throttle valve Configured to control the internal combustion engine using
The controller
An intake valve determination unit that determines whether deposits adhere or accumulate on the intake valve when the actual opening degree is larger than a predetermined value, using the actual rotation speed and the actual opening degree. When the first pressure difference calculated by subtracting the estimated first estimated intake pipe pressure from the actual intake pipe pressure is larger than the first determination value, it is determined that deposits are attached or accumulated on the intake valve An intake valve determination unit to
An intake valve map correction unit that corrects the intake valve map when it is determined that deposits adhere or deposit on the intake valve, and applying the first estimated intake pipe pressure to the intake valve map. An intake valve that corrects the intake valve map by learning using a difference between the first air amount calculated in step b and the second air amount calculated by applying the actual intake pipe pressure to the throttle valve map Map correction section,
Throttle valve determination to determine whether deposits adhere or accumulate on the throttle valve when a predetermined condition regarding correction of the intake valve map is satisfied and the actual opening degree is smaller than the predetermined value A second pressure difference calculated by subtracting the actual intake pipe pressure from the second estimated intake pipe pressure estimated using the actual rotational speed and the actual opening degree, and is larger than a second determination value And a throttle valve determination unit that determines that deposits are attached to or accumulated on the throttle valve.
A throttle valve map correction unit that corrects the throttle valve map when it is determined that deposits are deposited or accumulated on the throttle valve, and applying the second estimated intake pipe pressure to the throttle valve. By learning using the difference between the calculated third air amount and the fourth air amount calculated by applying the actual intake pipe pressure to the latest intake valve map after the establishment of the predetermined condition Throttle valve map correction unit that corrects the throttle valve map;
A control device for an internal combustion engine, comprising:

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