Control device for internal combustion engines

Abstract

This system accurately calculates the amount of particulate matter deposited based on pressure information. [Solution] The internal combustion engine 10 includes a GPF 18 provided in the exhaust passage 15 to collect particulate matter in the exhaust, and a pressure sensor 50 that detects pressure information including the pressure upstream of the GPF 18 from the exhaust. The control device 100 performs an accumulation amount calculation process to calculate the amount of particulate matter accumulated on the GPF 18 based on the pressure information. The accumulation amount calculation process includes a process to correct the amount of particulate matter accumulated in the GPF 18 according to the degree of variation in the amount of particulate matter accumulated in the exhaust flow direction.

Description

Technical Field

[0001] The present invention relates to a control device for an internal combustion engine.

Background Art

[0002] The internal combustion engine described in Patent Document 1 includes a filter in an exhaust passage for collecting particulate matter in exhaust gas. And the control device calculates the deposition amount of the particulate matter deposited on the filter based on the differential pressure before and after the filter, which is pressure information.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is desirable to accurately calculate the deposition amount of particulate matter calculated based on pressure information.

Means for Solving the Problems

[0005] The control device for an internal combustion engine that solves the above problems is applied to an internal combustion engine including a filter provided in an exhaust passage for collecting particulate matter in exhaust gas and a pressure sensor for detecting pressure information including the pressure on the upstream side of the exhaust of the filter. The control device has a processing circuit. The processing circuit executes a deposition amount calculation process for calculating the deposition amount of the particulate matter deposited on the filter based on the pressure information, and the deposition amount calculation process includes a process of correcting the deposition amount according to the degree of variation in the deposition amount of the particulate matter in the exhaust flow direction of the filter.

Effects of the Invention

[0006] According to this invention, the amount of particulate matter deposited, calculated based on pressure information, can be calculated with high accuracy. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram of an internal combustion engine to which one embodiment of the control device is applied. [Figure 2] Figure 2 is a flowchart showing the procedure for calculating the amount of sediment executed by the control device of this embodiment. [Figure 3] Figure 3 is a graph showing the relationship between the degree of variation in sediment volume, the sediment density counter, the correction coefficient, and the differential pressure. [Figure 4] Figure 4 is a flowchart showing the procedure for the index value calculation process performed by the control device of the same embodiment. [Figure 5] Figure 5 is a flowchart showing the procedure of processing performed by the control device of this embodiment. [Modes for carrying out the invention]

[0008] The following describes one embodiment of a control device for an internal combustion engine with reference to Figures 1 to 5. In this embodiment, the upstream side in the exhaust flow direction is referred to as "upstream," and the downstream side in the same exhaust flow direction is referred to as "downstream."

[0009] <Configuration of an internal combustion engine> As shown in Figure 1, the gasoline-fueled internal combustion engine 10 has multiple cylinders 10a. An intake passage 13 is connected to the intake port of each cylinder 10a. A throttle valve 14 is provided in the intake passage 13 to adjust the amount of intake air.

[0010] Each cylinder 10a has a combustion chamber equipped with a fuel injection valve 11. In the combustion chamber of each cylinder 10a, a mixture of air drawn in through the intake passage 13 and fuel injected from the fuel injection valve 11 is ignited by a spark discharge and combusted. The exhaust gas produced by the combustion of the mixture in the combustion chamber is discharged into an exhaust passage 15 connected to the exhaust port of the internal combustion engine 10.

[0011] A three-way catalyst 17 is provided in the exhaust passage 15. This three-way catalyst 17 oxidizes hydrocarbons (HC) and carbon monoxide (CO) contained in the exhaust to produce water and carbon dioxide. In addition, the three-way catalyst 17 reduces nitrogen oxides (NOx) contained in the exhaust to produce nitrogen.

[0012] A gasoline particulate filter (hereinafter referred to as GPF) 18 is provided in the exhaust passage 15 downstream of the three-way catalytic converter 17. The GPF 18 is a filter that collects particulate matter (hereinafter referred to as PM) in the exhaust gas, with the three-way catalytic converter supported on top.

[0013] The control device 100 is equipped with a CPU 110, memory 120, etc., and the CPU 110 executes programs stored in the memory 120 to perform various controls on the internal combustion engine 10.

[0014] The control device 100 receives detection signals from various sensors. For example, a pressure sensor 50 is provided in the exhaust passage 15, downstream of the three-way catalytic converter 17 and upstream of the GPF 18. This pressure sensor 50 detects pressure information, including the pressure upstream of the GPF 18. This pressure information is the differential pressure ΔP between the exhaust pressure EP upstream of the GPF 18 and atmospheric pressure. A crank angle sensor 53 is provided near the crankshaft of the internal combustion engine 10, and the engine speed NE of the internal combustion engine 10 is calculated based on the detection signal from this crank angle sensor 53. The internal combustion engine 10 is also equipped with an air flow meter 54 for detecting the intake air volume GA and a water temperature sensor 55 for detecting the coolant temperature THW of the internal combustion engine 10.

[0015] The control device 100 controls the fuel injection of the fuel injection valve 11, the opening degree of the throttle valve 14, etc. Further, when the output required for the internal combustion engine 10 is "0", the control device 100 executes a fuel cut that stops the fuel injection from the fuel injection valve 11.

[0016] The control device 100 calculates the PM deposition amount, which is the amount of PM deposited on the GPF 18. Then, various controls are performed based on the calculated PM deposition amount. An example of various controls is maintenance control of the GPF 18 and component protection control of the exhaust system. An example of maintenance control is regeneration control that is implemented to burn and remove the PM deposited on the GPF 18 when the PM deposition amount becomes equal to or greater than a predetermined regeneration determination value A. An example of maintenance control is notification control that notifies a warning to prompt maintenance at a maintenance factory to burn and remove the PM deposited on the GPF 18 when the PM deposition amount becomes equal to or greater than a predetermined over-deposition determination value B. An example of component protection control of the exhaust system is over-temperature rise suppression control that is implemented to suppress an excessive temperature rise of the GPF 18 when the PM deposition amount becomes equal to or greater than a predetermined protection determination value C. Examples of over-temperature rise suppression control include control to lower the temperature of the exhaust gas.

[0017] <Deposition amount calculation process> The control device 100 executes a deposition amount calculation process for calculating a first deposition amount Ps1, which is the deposition amount of PM deposited on the GPF 18, based on a differential pressure ΔP, which is pressure information.

[0018] FIG. 2 shows the procedure of the deposition amount calculation process executed by the control device 100. Note that the series of processes shown in FIG. 2 is realized by the CPU 110 executing a program stored in the memory 120 of the control device 100 at a predetermined cycle. Further, hereinafter, step numbers are represented by numbers preceded by "S".

[0019] In the series of processes shown in FIG. 2, the control device 100 first acquires the current differential pressure ΔP and the current intake air amount GA, and calculates a basic deposition amount Psb, which is a base value of the first deposition amount Ps1, based on these values (S100). In the process of S100, the larger the differential pressure ΔP is, the larger the basic deposition amount Psb is set.

[0020] When the process of S100 is executed, next, the control device 100 executes the process of S110. In the process of S110, the control device 100 calculates a correction coefficient K based on the deposition density counter Cd. The deposition density counter Cd is an index value indicating the degree of variation in the deposition amount of PM in the exhaust flow direction of the GPF18. Hereinafter, the degree of variation in the deposition amount of PM in the exhaust flow direction of the GPF18 is referred to as the "degree of variation in the deposition amount". When the value of the deposition density counter Cd is small, it indicates that the degree of variation in the deposition amount is larger than when the value of the deposition density counter Cd is large.

[0021] The correction coefficient K is a correction value for correcting the basic deposition amount Psb. The value of the correction coefficient K is variably set according to the value of the deposition density counter Cd such that the larger the value of the deposition density counter Cd is, the smaller the value becomes (see FIG. 3). Note that the value of the correction coefficient K that is variably set is, for example, a value of "1" or more.

[0022] When the process of S110 is executed, next, the control device 100 executes the process of S120. In the process of S120, the control device 100 executes a process of substituting the value obtained by multiplying the basic deposition amount Psb by the correction coefficient K into the first deposition amount Ps1.

[0023] When the process of S120 is executed, the control device 100 ends the execution of this process in the current cycle. <Calculation of the second deposition amount> The control device 100 executes a process of calculating a second deposition amount Ps2, which is the deposition amount of PM deposited on the GPF18 and is calculated based on the operating state of the internal combustion engine 10.

[0024] For example, the control device 100 acquires the engine rotational speed NE, the charging efficiency η, and the coolant temperature THW. The charging efficiency η is calculated by the control device 100 based on the engine rotational speed NE and the intake air volume GA.

[0025] The control device 100 calculates the PM emission amount Pa, which is the amount of PM discharged per unit time from the internal combustion engine 10 into the exhaust passage 15, based on the engine rotational speed NE, the charging efficiency η, and the coolant temperature THW.

[0026] Furthermore, the control device 100 acquires the currently calculated second deposit amount Ps2, GPF temperature T, and intake air amount GA, and calculates the PM combustion amount Pb, which is the amount of PM burned per hour in the GPF18, based on these values. The GPF temperature T is the temperature of the GPF18. The control device 100 calculates the GPF temperature T based on the engine rotation speed NE and the charging efficiency η. The GPF temperature T may also be detected using a sensor or the like.

[0027] The control device 100 then substitutes the value obtained by subtracting the PM combustion amount Pb from the PM emission amount Pa into the renewal amount ΔPs. Therefore, if the PM emission amount Pa is greater than the PM combustion amount Pb, the renewal amount ΔPs will be a positive value, and if the PM combustion amount Pb is greater than the PM emission amount Pa, the renewal amount ΔPs will be a negative value.

[0028] Next, the control device 100 updates the second accumulation amount Ps2 by adding the update amount ΔPs to the currently calculated second accumulation amount Ps2. Therefore, if the PM emission amount Pa is greater than the PM combustion amount Pb, the second accumulation amount Ps2 increases, while if the PM combustion amount Pb is greater than the PM emission amount Pa, the second accumulation amount Ps2 decreases. The calculation of the second accumulation amount Ps2 is performed by executing this process.

[0029] <About the sediment density counter> The above-mentioned sediment density counter Cd will be explained with reference to Figures 3 and 4. For example, when oxygen supply is initiated by fuel cut to a high-temperature GPF18, PM burns in the upstream portion of the GPF18. However, because oxygen is consumed by this combustion in the upstream portion, PM combustion does not proceed easily in the downstream portion of the GPF18. Therefore, when PM is burning, the degree of variation in the amount of PM deposited in the exhaust flow direction of the GPF18 tends to be large. On the other hand, when PM is not burning, the PM emitted from the internal combustion engine 10 is collected in the GPF18, so the degree of variation in the amount of PM deposited in the exhaust flow direction of the GPF18 tends to be small.

[0030] The inventors have found that the relationship between differential pressure ΔP and PM deposition amount tends to change depending on the degree of variation in deposition amount. Specifically, as shown in Figure 3, even if the actual PM deposition amount in GPF18 is the same, when the degree of variation in deposition amount is large, the differential pressure ΔP tends to be smaller compared to when the variation is small. Therefore, when the degree of variation in deposition amount is large, the first deposition amount Ps1 calculated may be less than the actual deposition amount compared to when the variation is small.

[0031] Therefore, the control device 100 of this embodiment calculates the sediment density counter Cd such that the value of the sediment density counter Cd, which is an index value indicating the degree of variation in sediment amount, increases as the degree of variation in sediment amount decreases. The control device 100 then corrects the first sediment amount Ps1 such that the first sediment amount Ps1 increases as the degree of variation in sediment amount increases by calculating the correction coefficient K such that the value of the correction coefficient K increases as the value of the sediment density counter Cd decreases.

[0032] Figure 4 shows the procedure for calculating the index value used to calculate the sediment density counter Cd. The series of processes shown in Figure 4 are realized by the CPU 110 executing a program stored in the memory 120 of the control device 100 at predetermined intervals. The initial value of the sediment density counter Cd is "0".

[0033] In the series of processes shown in Figure 4, the control device 100 first determines whether or not PM is currently burning (S200). In process S200, for example, if the first accumulation amount Ps1 or the second accumulation amount Ps2 is decreasing, the control device 100 determines that PM is currently burning. On the other hand, in process S200, for example, if the first accumulation amount Ps1 or the second accumulation amount Ps2 is not decreasing, the control device 100 determines that PM is not currently burning.

[0034] In the process of S200, if it is determined that PM is currently burning (S100: YES), the control device 100 performs a process to subtract a predetermined value A from the current value of the sediment density counter Cd (S210). A lower limit is set for the sediment density counter Cd. For example, the lower limit is "0". If the value of the sediment density counter Cd after the subtraction in the process of S210 is less than the lower limit, the control device 100 performs a lower limit guard for the sediment density counter Cd by substituting the lower limit value into the sediment density counter Cd.

[0035] On the other hand, in the process of S200, if it is determined that PM is not currently burning (S100: NO), the control device 100 performs a process of adding a predetermined value B to the current value of the deposit density counter Cd (S220). Here, when the PM emission Pa is high, the amount of PM collected by the GPF18 increases compared to when it is low, so the rate at which the degree of variation in the amount of deposit decreases becomes faster. Therefore, when the PM emission Pa is high, it is desirable to increase the rate at which the deposit density counter Cd increases compared to when it is low. To this end, the control device 100 of this embodiment variably sets the value B so that the value B becomes larger as the PM emission Pa increases. Incidentally, the value B may be a fixed value.

[0036] In addition, an upper limit value is set for the deposition density counter Cd. For example, the upper limit value is the value of the deposition density counter Cd when the deposition amount of PM in the exhaust gas flow direction of GPF18 is uniform and the degree of variation in the deposition amount is minimized. Such an upper limit value is set to an appropriate value through preliminary tests or the like. When the value of the deposition density counter Cd after being added in the process of S220 becomes larger than the upper limit value, the control device 100 performs an upper limit guard of the deposition density counter Cd by substituting the upper limit value into the deposition density counter Cd.

[0037] When either the process of S210 or the process of S220 is completed, the control device 100 ends the execution of this process in the current cycle. <PM Deposition Amount Selection Process> The control device 100 executes a selection process of selecting either the first deposition amount Ps1 or the second deposition amount Ps2 as the PM deposition amount for control.

[0038] Fig. 5 shows the procedure of the selection process executed by the control device 100. The series of processes shown in Fig. 5 is realized by the CPU 110 executing a program stored in the memory 120 of the control device 100 at predetermined intervals.

[0039] In the series of processes shown in Fig. 5, the control device 100 first acquires the currently calculated first deposition amount Ps1 and the currently calculated second deposition amount Ps2 (S300). When the process of S300 is executed, next, the control device 100 executes the process of S310.

[0040] In the process of S310, the control device 100 substitutes the deposition amount with the larger value between the first deposition amount Ps1 and the second deposition amount Ps2 into the deposition amount for component protection Psp. The deposition amount for component protection Psp is the PM deposition amount referred to when performing the component protection control of the exhaust system described above. Therefore, in the component protection control of the exhaust system, a comparison between the deposition amount for component protection Psp and the protection determination value C is performed.

[0041] After executing the process in S310, the control device 100 then executes the process in S320. In the process of S320, the control device 100 substitutes the smaller of the first accumulation amount Ps1 and the second accumulation amount Ps2 into the maintenance accumulation amount Psm. The maintenance accumulation amount Psm is the PM accumulation amount referenced when performing the maintenance control described above. Therefore, in the maintenance control, the maintenance accumulation amount Psm is compared with the regeneration judgment value A. In addition, in the maintenance control, the maintenance accumulation amount Psm is compared with the over-accumulation judgment value B.

[0042] Once the process in S320 described above is completed, the control device 100 terminates the execution of this process for the current cycle. <Operation and Effects of This Embodiment> (1) The control device 100 performs a deposition amount calculation process to calculate a first deposition amount Ps1, which is the amount of PM deposited in the GPF18, based on the differential pressure ΔP, which is pressure information. The deposition amount calculation process includes a process to correct the first deposition amount Ps1 according to the degree of variation in the amount of PM deposited in the exhaust flow direction of the GPF18.

[0043] The relationship between the differential pressure ΔP and the PM accumulation amount tends to change depending on the degree of variation in the PM accumulation amount in the exhaust flow direction of the GPF18. Therefore, the control device 100 of this embodiment performs a process to correct the first accumulation amount Ps1, which is calculated based on the differential pressure ΔP, according to the degree of variation in the PM accumulation amount in the exhaust flow direction of the GPF18. Consequently, the first accumulation amount Ps1 calculated based on the differential pressure ΔP can be calculated with greater accuracy compared to the case where the first accumulation amount Ps1 is calculated without considering the degree of variation in the accumulation amount.

[0044] (2) In the sediment volume calculation process, if the degree of variation in sediment volume is large, the first sediment volume Ps1 is corrected to be larger than when the degree of variation is small. Even if the actual amount of PM deposited in GPF18 is the same, if the degree of variation in the amount of deposited is large, the differential pressure ΔP tends to be smaller compared to the case where the variation is small. Therefore, when the degree of variation in the amount of deposited is large, the first deposited amount Ps1 calculated tends to be less than the actual deposited amount compared to the case where the variation is small. Accordingly, in this embodiment, when the degree of variation in the amount of deposited is large, the first deposited amount Ps1 is corrected to be larger than when the degree of variation in the amount of deposited is small. Thus, the first deposited amount Ps1 can be appropriately calculated according to the degree of variation in the amount of deposited.

[0045] (3) The control device 100 performs an index value calculation process to calculate a sediment density counter Cd, which is an index value indicating the degree of variation in sediment volume. In the index value calculation process, the value of the sediment density counter Cd is updated to indicate that the degree of variation in sediment volume is large when PM is burning. On the other hand, in the index value calculation process, the value of the sediment density counter Cd is updated to indicate that the degree of variation in sediment volume is small when PM is not burning.

[0046] When oxygen supply is initiated to the high-temperature GPF18 by fuel cut-off, PM burns in the upstream portion of the GPF18. However, because oxygen is consumed by this combustion in the upstream portion, PM combustion does not proceed easily in the downstream portion of the GPF18. Therefore, when PM is burning, the degree of variation in the amount of PM deposited in the GPF18 in the exhaust flow direction tends to be large. On the other hand, when PM is not burning, the PM discharged from the combustion chamber is collected in the GPF18, so the degree of variation in the amount of PM deposited in the GPF18 in the exhaust flow direction tends to be small.

[0047] Therefore, in this embodiment, a sediment density counter Cd, which is an index value related to the degree of variation in sediment volume, is calculated. When the value of this sediment density counter Cd is small, it indicates that the degree of variation in sediment volume is greater than when the value of the sediment density counter Cd is large.

[0048] As mentioned above, when PM burns, the degree of variation in the amount of sediment increases, so the value of the sediment density counter Cd is updated to reflect this increased variation. In other words, when PM is burning, the value of the sediment density counter Cd is updated to decrease. On the other hand, when PM is not burning, the degree of variation in the amount of sediment decreases, so the value of the sediment density counter Cd is updated to reflect this decreased variation. In other words, when PM is not burning, the value of the sediment density counter Cd is updated to increase. Therefore, an appropriate index value indicating the degree of variation in the amount of sediment can be calculated.

[0049] (4) The control device 100 performs a process to acquire a first accumulation amount Ps1 calculated based on the differential pressure ΔP and a second accumulation amount Ps2 calculated based on the operating state of the internal combustion engine 10 (process S300 shown in Figure 5). The control device 100 then performs a process to substitute the larger of the first accumulation amount Ps1 and the second accumulation amount Ps2 into the component protection accumulation amount Psp (process S310 shown in Figure 5). The control device 100 then performs component protection control of the exhaust system using the component protection accumulation amount Psp.

[0050] Therefore, compared to the case where the smaller of the first accumulation amount Ps1 and the second accumulation amount Ps2 is substituted for the accumulation amount Psp for component protection, the exhaust system component protection control can be implemented appropriately.

[0051] For example, in this embodiment, when the component protection deposit amount Psp exceeds the protection judgment value C, overheating suppression control is implemented to suppress overheating of the GPF18. Here, when the component protection deposit amount Psp is large, the opportunities for the component protection deposit amount Psp to exceed the protection judgment value C increase compared to when the component protection deposit amount Psp is small. Therefore, the opportunities for overheating suppression control to be executed increase, and overheating of the GPF18 is appropriately suppressed.

[0052] (5) The control device 100 performs a process to acquire a first accumulation amount Ps1 calculated based on the differential pressure ΔP and a second accumulation amount Ps2 calculated based on the operating state of the internal combustion engine 10 (process S300 shown in Figure 5). The control device 100 then performs a process to substitute the smaller of the first accumulation amount Ps1 and the second accumulation amount Ps2 into the maintenance accumulation amount Psm (process S320 shown in Figure 5). The control device 100 then performs the above maintenance control using the maintenance accumulation amount Psm.

[0053] Therefore, compared to the case where the larger of the first deposit amount Ps1 and the second deposit amount Ps2 is substituted for the maintenance deposit amount Psm, maintenance control can be implemented more appropriately.

[0054] For example, in this embodiment, when the maintenance deposit amount Psm reaches or exceeds the regeneration judgment value A, regeneration control of the GPF18 is performed. Here, when the maintenance deposit amount Psm is small, the opportunity for the maintenance deposit amount Psm to reach or exceed the regeneration judgment value A decreases compared to when the maintenance deposit amount Psm is large. Therefore, the opportunities to perform regeneration control are reduced, and thus the frequent execution of regeneration control can be suppressed.

[0055] Furthermore, in this embodiment, for example, since the notification control described above is implemented, if the maintenance deposit amount Psm exceeds the over-deposit determination value B, a warning is issued prompting maintenance at a repair shop to burn off the PM accumulated in the GPF18. Here, when the maintenance deposit amount Psm is small, the opportunity for the maintenance deposit amount Psm to exceed the over-deposit determination value B decreases compared to when the maintenance deposit amount Psm is large. Therefore, the opportunity to issue a warning decreases, thus preventing frequent warnings.

[0056] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0057] In the S200 process shown in Figure 4, whether or not PM is burning was determined based on the trend of change in the first accumulation amount Ps1 or the second accumulation amount Ps2. However, whether or not PM is burning may be determined by other methods. For example, if the PM burning amount Pb is greater than "0", it may be determined that PM is burning. Alternatively, whether or not PM is burning may be determined based on, for example, the engine rotational speed NE and the engine load factor.

[0058] In the above embodiment, it was shown that when the value of the sediment density counter Cd is small, the degree of variation in sediment amount is larger compared to when the value of the sediment density counter Cd is large. Conversely, it may be shown that when the value of the sediment density counter Cd is small, the degree of variation in sediment amount is smaller compared to when the value of the sediment density counter Cd is large. In this modified example, the same effect as in the above embodiment can be obtained by variably setting the value of the correction coefficient K such that the value of the correction coefficient K becomes smaller as the value of the sediment density counter Cd decreases.

[0059] The above pressure information was the differential pressure ΔP between the exhaust pressure EP upstream of GPF18 and atmospheric pressure. Alternatively, the above pressure information may also be the differential pressure between the exhaust pressure EP upstream of GPF18 and the exhaust pressure downstream of GPF18.

[0060] The second deposit amount Ps2 may be calculated in a manner different from that of the above embodiment. The placement position of the GPF18 in the exhaust passage 15 can be changed as appropriate. • GPF18 may be a filter that does not support a three-way catalyst.

[0061] The control device 100 is not limited to one that includes a CPU and memory and performs software processing. For example, the control device 100 may include a dedicated hardware circuit, such as an ASIC, that performs hardware processing for at least a portion of what is processed by software in the above embodiment. That is, the control device 100 may include a processing circuit having any of the following configurations (a) to (c): (a) A processing circuit comprising one or more processing units that perform all of the above processing according to a program, and one or more program storage devices such as ROMs that store the program. (b) A processing circuit comprising one or more processing units and one or more program storage devices that perform a portion of the above processing according to a program, and one or more dedicated hardware circuits that perform the remaining processing. (c) A processing circuit comprising one or more dedicated hardware circuits that perform all of the above processing. The program storage device, i.e., computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer. [Explanation of Symbols]

[0062] Internal combustion engine… 10a…Cylinder 11…Fuel injector 13…Intake passage 14…Throttle valve 15…Exhaust passage 17…Through catalytic converter 18…GPF 18…Gasoline particulate filter 50…Pressure sensor 53…Crank angle sensor 54…Air flow meter 55…Water temperature sensor 100…Control unit 110…CPU 120…Memory

Claims

1. A control device for an internal combustion engine, comprising a filter installed in the exhaust passage for collecting particulate matter in the exhaust, and a pressure sensor for detecting pressure information including the pressure upstream of the exhaust from the filter, It has a processing circuit, The aforementioned processing circuit is A deposit amount calculation process is performed to calculate the amount of particulate matter deposited on the filter based on the pressure information, The aforementioned deposit amount calculation process includes a process for correcting the deposit amount according to the degree of variation in the amount of particulate matter deposited in the exhaust flow direction of the filter. Control device for internal combustion engines.

2. In the aforementioned deposit amount calculation process, if the degree of variation is large, the deposit amount is corrected to be larger than when the degree of variation is small. A control device for an internal combustion engine according to claim 1.

3. The aforementioned processing circuit is An index value calculation process is performed to calculate an index value that indicates the degree of variation, In the index value calculation process, the index value is updated to indicate that the degree of variation increases when the particulate matter is burning, while the index value is updated to indicate that the degree of variation decreases when the particulate matter is not burning. A control device for an internal combustion engine according to claim 1.

4. The aforementioned processing circuit is A process to obtain the amount of deposit calculated based on the pressure information as the first amount of deposit, The process involves obtaining a second deposit amount, which is the amount of particulate matter deposited on the filter and is calculated based on the operating state of the internal combustion engine. The exhaust system component protection control is performed using the larger of the first and second accumulation amounts. A control device for an internal combustion engine according to claim 1.

5. The aforementioned processing circuit is A process to obtain the amount of deposit calculated based on the pressure information as the first amount of deposit, The process involves obtaining a second deposit amount, which is the amount of particulate matter deposited on the filter and is calculated based on the operating state of the internal combustion engine. Maintenance control of the filter is performed using the smaller of the first and second accumulation amounts. A control device for an internal combustion engine according to claim 1.

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