JP2016130456A - Internal combustion engine control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to accurately estimate a PM accumulation quantity of a filter for collecting the PM.SOLUTION: A single-tap filter 31 that collects PM (particulate matter) in exhaust gas of an engine 11 is constituted to have at least one cell an outlet side of which is opened out of remaining cells except for partial cells inlet sides of which are closed out of a plurality of cells. Since a predetermined correlation is held among a PM accumulation quantity of the single-tap filter 31, a PM quantity (sensor-detected PM quantity) detected by a PM sensor 32, and a PM collection rate of the single-tap filter 31, an ECU 30 estimates (calculates) the PM accumulation quantity on the basis of the sensor-detected PM quantity and the PM collection rate. At that time, in the light of a change in the PM collection rate in response to parameters such as the PM accumulation quantity, an exhaust gas flow rate, an exhaust gas pressure, an exhaust gas temperature, and an ash accumulation quantity, the PM collection rate used to estimate the PM accumulation quantity is changed in response to these parameters.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an internal combustion engine control device including a filter that collects particulate matter in exhaust gas from an internal combustion engine.

  In internal combustion engines mounted on vehicles, demand for in-cylinder gasoline engines is expected to increase as fuel efficiency regulations are tightened. However, the in-cylinder injection type gasoline engine has a problem that the amount of PM (Particulate Matter) emission increases as compared with the intake port injection type gasoline engine. As a countermeasure, there is one in which a filter for collecting PM discharged from the engine is disposed in the exhaust passage of the engine.

  In such a system equipped with a filter for collecting PM, in order to perform regeneration control of the filter (control for burning and removing PM accumulated on the filter) and abnormality diagnosis, etc., the amount of PM accumulated on the filter (in the filter) It may be necessary to estimate the amount of PM deposited.

  As a technique for estimating the PM accumulation amount of the filter for collecting PM, for example, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-262983), the differential pressure across the filter, the exhaust gas flow rate, and the exhaust gas There is one in which the PM accumulation amount of the filter is calculated based on the viscosity, and the exhaust viscosity is corrected in accordance with the exhaust gas flow rate.

  Conventionally, in a filter for collecting PM, the inlet side of some of the plurality of cells provided in the filter is closed, and the outlet side of the remaining cells (that is, cells whose inlet side is opened) is closed. There is a structure.

JP 2007-262983 A

  In the above conventional filter, almost all of the exhaust gas flowing into the cell with the inlet side opened passes through the porous partition wall (partition wall) that partitions the cell, flows out of the cell with the outlet side opened, and is discharged. Although the PM in the exhaust gas is collected when the gas passes through the partition wall, there is a drawback that the pressure loss of the exhaust gas increases.

  In order to reduce the pressure loss of the exhaust gas by the filter, the applicant of the present invention has at least one cell in which the inlet side of some of the plurality of cells is closed and the outlet side of the remaining cells is opened. We are studying a system with a single plug filter having the above structure (or a structure having at least one cell in which the outlet side of some cells is closed and the inlet side among the remaining cells is opened). The following new issues were found during the research process.

  In a system equipped with a single-ended filter, the pressure loss of the exhaust gas by the filter can be reduced. However, since the change in the differential pressure across the filter due to the accumulation of PM is reduced accordingly, the filter as in the technique of Patent Document 1 is used. In the method of estimating the PM accumulation amount of the filter by using the differential pressure before and after, it is difficult to accurately estimate the PM accumulation amount of the filter. In addition, the technique disclosed in Patent Document 1 has a drawback in that it increases the cost and complexity of the system because it is necessary to provide a differential pressure sensor for detecting the differential pressure across the filter.

  Therefore, the problem to be solved by the present invention is to provide a control device for an internal combustion engine capable of accurately estimating the amount of PM deposited on the filter for collecting PM without causing an increase in system cost or complication. There is.

  In order to solve the above problems, the present invention is a filter for collecting particulate matter (hereinafter referred to as “PM”) in exhaust gas of an internal combustion engine (11), and a plurality of filters provided on the filter. A structure having at least one cell in which the inlet side of some of the cells (33) is closed and the outlet side of the remaining cells is open or the outlet side of some of the cells is closed and Of these, a single plug filter (31) having a structure having at least one cell whose inlet side is open, a PM sensor (32) for detecting the amount of PM in the exhaust gas that has passed through the single plug filter (31), A configuration comprising estimation means (30) for estimating the amount of PM deposited on the single plug filter (31) based on the PM amount detected by the PM sensor (32) and the PM collection rate of the single plug filter (31); It is a thing.

  A predetermined correlation is established between the amount of PM deposited on the single plug filter, the amount of PM detected by the PM sensor (the amount of PM passing through the single plug filter), and the PM collection rate of the single plug filter. Therefore, if the PM amount detected by the PM sensor and the PM collection rate are used, the PM accumulation amount can be estimated (calculated). At that time, since the amount of accumulated PM can be estimated without using the differential pressure across the single plug filter, the PM accumulated amount can be accurately estimated even when the amount of accumulated PM is small and the differential pressure across the single plug filter is small. can do. Moreover, since it is not necessary to provide a differential pressure sensor for detecting the differential pressure across the single plug filter, it is possible to avoid an increase in system cost and complexity.

FIG. 1 is a diagram showing a schematic configuration of an engine control system in one embodiment of the present invention. FIG. 2 is a cross-sectional view of the single-ended filter along the exhaust gas flow direction. FIG. 3 is a cross-sectional view taken along the direction perpendicular to the direction of exhaust gas flow on the inlet side of the single-ended filter. FIG. 4 is a cross-sectional view taken along a direction perpendicular to the exhaust gas flow direction on the outlet side of the single plug filter. FIG. 5 is an output characteristic diagram of a linear type PM sensor. FIG. 6 is an output characteristic diagram of the integration type PM sensor. FIG. 7 is a time chart for explaining the reproduction control. FIG. 8 is a diagram showing the relationship between the PM deposition amount and the PM collection rate. FIG. 9 is a diagram showing the relationship between the exhaust gas flow rate and the PM collection rate. FIG. 10 is a diagram showing the relationship between the exhaust pressure and the PM collection rate. FIG. 11 is a diagram showing the relationship between the exhaust gas temperature and the PM collection rate. FIG. 12 is a diagram showing the relationship between the ash deposition amount and the PM collection rate. FIG. 13 is a flowchart showing a process flow of the PM accumulation amount estimation routine.

Hereinafter, an embodiment embodying a mode for carrying out the present invention will be described.
First, a schematic configuration of the engine control system will be described with reference to FIG.

  An engine 11 that is an in-cylinder internal combustion engine is an in-cylinder injection gasoline engine that directly injects gasoline as fuel into a cylinder. An air cleaner 13 is provided at the most upstream portion of the intake pipe 12 of the engine 11, and an air flow meter 14 for detecting the intake air amount is provided downstream of the air cleaner 13. A throttle valve 16 whose opening is adjusted by a motor 15 and a throttle opening sensor 17 for detecting the opening (throttle opening) of the throttle valve 16 are provided on the downstream side of the air flow meter 14.

  Further, a surge tank 18 is provided on the downstream side of the throttle valve 16, and an intake pipe pressure sensor 19 for detecting the intake pipe pressure is provided in the surge tank 18. The surge tank 18 is provided with an intake manifold 20 that introduces air into each cylinder of the engine 11. Each cylinder of the engine 11 has a fuel injection valve 21 that directly injects fuel (gasoline) into the cylinder. It is attached. An ignition plug 22 is attached to the cylinder head of the engine 11 for each cylinder, and the air-fuel mixture in each cylinder is ignited by spark discharge of the ignition plug 22 of each cylinder.

On the other hand, the exhaust pipe 23 of the engine 11 is provided with an exhaust gas sensor 24 (such as an air-fuel ratio sensor or an oxygen sensor) that detects the air-fuel ratio or rich / lean of the exhaust gas. A catalyst 25 such as a three-way catalyst for purifying CO, HC, NO _{x and the} like in the gas is provided.

  A single plug filter 31 that collects PM (Particulate Matter) in the exhaust gas of the engine 11 is provided on the downstream side of the catalyst 25 in the exhaust pipe 23 of the engine 11. The catalyst 25 and the single plug filter 31 may be accommodated in one case or in separate cases. Furthermore, a PM sensor 32 that detects the amount of PM in the exhaust gas that has passed through the single plug filter 31 is provided on the downstream side of the single plug filter 31.

  A cooling water temperature sensor 26 that detects the cooling water temperature and a knock sensor 27 that detects knocking are attached to the cylinder block of the engine 11. A crank angle sensor 29 that outputs a pulse signal every time the crankshaft 28 rotates by a predetermined crank angle is attached to the outer peripheral side of the crankshaft 28, and the crank angle and the engine are determined based on the output signal of the crank angle sensor 29. The rotation speed is detected.

  Outputs of these various sensors are input to an electronic control unit (hereinafter referred to as “ECU”) 30. The ECU 30 is mainly composed of a microcomputer, and executes various engine control programs stored in a built-in ROM (storage medium), so that the fuel injection amount and the ignition timing are determined according to the engine operating state. The throttle opening (intake air amount) and the like are controlled.

  As shown in FIGS. 2 to 4, the single plug filter 31 has a plurality of cells 33 extending in the exhaust gas flow direction (direction from the inlet side to the outlet side) partitioned by a porous partition wall (partition wall) 34. The end portion on the inlet side of some of the cells 33 among the plurality of cells 33 is closed by the sealing member 35, and the outlet side of all the cells 33 is open. In this embodiment, a cell 33A in which the inlet side is closed and the outlet side is opened (hereinafter referred to as “inlet closed cell”) 33A, and a cell in which both the inlet side and the outlet side are opened (hereinafter referred to as “double-side open cell”) 33B; Are alternately arranged so as to be adjacent to each other.

  In the single plug filter 31, when exhaust gas flows into the cell 33B from the inlet side of the both-side open cell 33B, the pressure in the both-side open cell 33B rises, and the pressure in the inlet-closed cell 33A is increased in the both-side open cell 33B. Relative to the pressure of. For this reason, a part of the exhaust gas from the open cells 33 on both sides passes through the porous partition wall 34 and flows into the inlet closed cell 33 and flows out of the cell 33 from the outlet side of the inlet closed cell 33. At that time, PM (for example, SOOT particles having a particle diameter of 20 to 100 nm) in the exhaust gas is collected by adhering to the pores (inner wall surfaces of the pores) and the surface wall surfaces of the partition walls 34. In addition, ash, which is a non-combustible substance in the exhaust gas (for example, ash due to the oil of the engine 11), is also collected by adhering to the pores of the partition wall 34 and the surface wall surface.

  The PM sensor 32 is preferably a PM sensor having a linear output characteristic, but may be a PM sensor having an integral output characteristic. As shown in FIG. 5, in the linear type PM sensor, the sensor output changes linearly according to the amount of PM in the exhaust gas. On the other hand, as shown in FIG. 6, in the integration type PM sensor, when the integrated value of the PM amount adhering to the PM sensor exceeds a certain value, the sensor output changes in accordance with the integrated value of the PM amount.

  By the way, in the system provided with the single plug filter 31 for collecting PM, if the amount of PM deposited on the single plug filter 31 (the amount of PM deposited on the single plug filter 31) becomes too large, the pressure loss of the exhaust gas increases. . For this reason, as shown in FIG. 7, the ECU 30 performs regeneration control for burning and removing the PM collected by the single plug filter 31 to regenerate the single plug filter 31 (PM of the single plug filter 31). The amount of deposition is reduced). The regeneration control includes, for example, fuel cut control that is executed when a predetermined fuel cut execution condition is satisfied (for example, during deceleration). Further, when the PM accumulation amount of the single plug filter 31 exceeds a predetermined upper limit value (see FIG. 7), for example, control for making the air-fuel ratio lean or control for increasing the exhaust temperature is executed as regeneration control.

  At this time, in this embodiment, the ECU 30 executes a PM accumulation amount estimation routine of FIG. 13 to be described later, so that the sensor detected PM amount that is the PM amount detected by the PM sensor 32 and the PM collection rate of the single plug filter 31 are obtained. Based on the above, the PM accumulation amount of the single plug filter 31 is estimated.

There is a predetermined correlation between the PM accumulation amount (for example, the PM accumulation amount per predetermined time), the sensor detected PM amount (for example, the PM amount per predetermined time that has passed through the single plug filter 31), and the PM collection rate. [Relationship shown by the following formula (1)] holds.
PM accumulation amount = sensor detection PM amount × PM collection rate / (1-PM collection rate) (1)
Therefore, if the sensor detected PM amount and the PM collection rate are used, the PM accumulation amount can be estimated (calculated) by the above equation (1).

  In addition, the single plug filter 31 has a characteristic that the PM collection rate changes in accordance with the PM accumulation amount. Specifically, as shown in FIG. 8, after the PM is removed by regeneration control or the like (after the PM deposition amount becomes almost zero), the single-ended filter 31 first has a pore inside the partition wall 34. Then, PM is deposited, and thereafter, PM is deposited on the surface of the partition wall 34. In the pore accumulation region where PM accumulates in the pores of the partition wall 34 (region where the PM deposition amount is relatively small), the PM trapping rate decreases after increasing once as the PM deposition amount increases. Thereafter, in the surface layer deposition region where PM is deposited on the surface layer wall surface of the partition wall 34, the PM collection rate is substantially constant. In consideration of such characteristics, in this embodiment, the PM collection rate used for estimating the PM accumulation amount is changed according to the previous value (integrated value up to the previous time) of the PM accumulation amount.

  Further, the single plug filter 31 has a characteristic that the PM collection rate changes according to the flow rate of the exhaust gas passing through the single plug filter 31. Specifically, as shown in FIG. 9, the single plug filter 31 has a substantially constant PM collection rate in a region where the exhaust gas flow rate is relatively low, but is exhausted in a region where the exhaust gas flow rate is relatively high. As the gas flow rate increases, the exhaust gas flow rate that blows through without passing through the partition wall 34 increases (that is, the exhaust gas flow rate that passes through the partition wall 34 decreases), and the PM collection rate decreases. In consideration of such characteristics, in this embodiment, the PM collection rate used for estimating the PM accumulation amount is changed according to the flow rate of the exhaust gas passing through the single plug filter 31.

  Further, the single plug filter 31 has a characteristic that the PM collection rate changes according to the exhaust pressure upstream of the single plug filter 31. Specifically, as shown in FIG. 10, in the single plug filter 31, as the exhaust pressure increases, the flow rate of exhaust gas passing through the partition wall 34 increases, and the PM collection rate increases. In consideration of such characteristics, in this embodiment, the PM collection rate used for estimating the PM accumulation amount is changed according to the exhaust pressure on the upstream side of the single plug filter 31.

  Further, the single plug filter 31 has a characteristic that the PM collection rate changes according to the temperature of the exhaust gas flowing into the single plug filter 31. Specifically, as shown in FIG. 11, in the single plug filter 31, as the exhaust gas temperature increases, the Brownian motion of PM becomes active and the PM collection rate increases. In consideration of such characteristics, in this embodiment, the PM collection rate used for estimating the PM accumulation amount is changed according to the temperature of the exhaust gas flowing into the one-side plug filter 31. In addition, you may make it change PM collection rate used for estimation of PM deposition amount according to the temperature of the exhaust gas which flows out out of the single plug filter 31, or the temperature of the single plug filter 31. FIG.

  Further, the single plug filter 31 has a characteristic that the PM collection rate changes according to the amount of ash deposited on the single plug filter 31. Specifically, as shown in FIG. 12, in the single plug filter 31, as the ash deposition amount increases, the exhaust gas flow rate passing through the partition wall 34 and the exhaust gas flow rate contacting the partition wall 34 decrease, and the PM trapping. The collection rate becomes low. In consideration of such characteristics, in this embodiment, the PM collection rate used for estimating the PM accumulation amount is changed according to the ash accumulation amount of the single plug filter 31.

  That is, in this embodiment, considering that the PM collection rate changes according to parameters such as the PM deposition amount, the exhaust gas flow rate, the exhaust pressure, the exhaust gas temperature, the ash deposition amount, etc., according to these parameters. Change the PM collection rate used to estimate the amount of accumulated PM.

Hereinafter, the processing content of the PM accumulation amount estimation routine of FIG. 13 executed by the ECU 30 in the present embodiment will be described.
The PM accumulation amount estimation routine shown in FIG. 13 is repeatedly executed at a predetermined period during the power-on period of the ECU 30, and serves as estimation means in the claims. When this routine is started, it is first determined in step 101 whether or not regeneration control is being executed. If it is determined that regeneration control is being executed, the processing from step 102 is executed. This routine is terminated without doing so.

On the other hand, if it is determined in step 101 that the regeneration control is not being executed, the process proceeds to step 102 where the PM accumulation amount at the end of the regeneration control is calculated as the initial value of the PM accumulation amount. At this time, if the execution time of the regeneration control is equal to or longer than a predetermined time (a time necessary for removing the PM accumulated on the one plug filter 31), the initial value of the PM accumulation amount is set to “0”. On the other hand, when the execution time of the regeneration control is shorter than the predetermined time, the PM accumulation amount is determined based on the PM accumulation amount at the start of the regeneration control, the regeneration control execution time, the temperature of the single plug filter 31, and the like. An initial value (PM accumulation amount at the end of regeneration control) is calculated by a map or a mathematical expression.
Thereafter, the process proceeds to step 103, and the PM amount detected by the PM sensor 32 (for example, the PM amount per predetermined time that has passed through the single plug filter 31) is read as the sensor detected PM amount.

  Thereafter, the process proceeds to step 104, and the base PM collection rate is calculated by a map or a mathematical formula according to the initial value or the previous value of the PM accumulation amount. At this time, immediately after the end of the regeneration control (the first time after the end), the base PM collection rate is calculated by a map or the like according to the initial value of the PM accumulation amount. Thereafter, the base PM collection rate is calculated by a map or the like according to the previous value of PM accumulation amount (integrated value up to the previous time). The map or formula of the base PM collection rate is created in advance in consideration of the relationship between the PM accumulation amount and the PM collection rate (see FIG. 8) based on test data, design data, etc., and stored in the ROM of the ECU 30. Has been.

  Thereafter, the process proceeds to step 105, and the first correction coefficient of the PM collection rate is calculated by a map or a mathematical expression or the like according to the exhaust gas flow rate passing through the single plug filter 31. At this time, for example, the intake air flow rate is used as substitute information for the exhaust gas flow rate. Alternatively, the exhaust gas flow rate may be calculated based on the engine operating state (for example, engine rotational speed, load, etc.). The map or formula of the first correction coefficient is created in advance in consideration of the relationship between the exhaust gas flow rate and the PM collection rate (see FIG. 9) based on test data, design data, etc., and is stored in the ROM of the ECU 30. Has been.

  Thereafter, the process proceeds to step 106, and the second correction coefficient of the PM collection rate is calculated by a map or a mathematical formula or the like according to the exhaust pressure on the upstream side of the single plug filter 31. At this time, the exhaust pressure is calculated based on the engine operating state (for example, engine rotation speed, load, etc.). Alternatively, in the case of a system including a pressure sensor that detects the exhaust pressure upstream of the single plug filter 31, the exhaust pressure detected by the pressure sensor is used. The second correction coefficient map or mathematical expression is created in advance in consideration of the relationship between the exhaust pressure and the PM collection rate (see FIG. 10) based on test data, design data, and the like, and is stored in the ROM of the ECU 30. ing.

  Thereafter, the process proceeds to step 107, and the third correction coefficient of the PM collection rate is calculated by a map or a mathematical formula or the like according to the exhaust gas temperature flowing into the one-end filter 31. At this time, the exhaust gas temperature is calculated based on the engine operating state (for example, engine rotation speed, load, etc.). Or in the case of the system provided with the temperature sensor which detects the exhaust gas temperature which flows into the single plug filter 31, the exhaust gas temperature detected with the temperature sensor is used. The map or mathematical expression of the third correction coefficient is created in advance in consideration of the relationship between the exhaust gas temperature and the PM collection rate (see FIG. 11) based on test data, design data, etc., and is stored in the ROM of the ECU 30. Has been. Note that the third correction coefficient of the PM collection rate may be calculated by a map or a mathematical expression according to the temperature of the exhaust gas flowing out from the single plug filter 31 or the temperature of the single plug filter 31.

  Thereafter, the process proceeds to step 108, and the fourth correction coefficient of the PM collection rate is calculated by a map or a mathematical expression or the like according to the ash accumulation amount of the single plug filter 31. At this time, the ash accumulation amount is calculated based on the engine operating state (for example, engine rotation speed, load, etc.). The map or formula of the fourth correction coefficient is created in advance in consideration of the relationship between the ash deposition amount and the PM collection rate (see FIG. 12) based on test data, design data, and the like, and is stored in the ROM of the ECU 30. Has been.

  Thereafter, the process proceeds to step 109, where the base PM collection rate is corrected using the first to fourth correction coefficients, and the final PM collection rate is obtained. Considering that the PM collection rate changes according to parameters such as the amount of PM deposition, the exhaust gas flow rate, the exhaust pressure, the exhaust gas temperature, and the amount of ash deposition due to the processing of these steps 104 to 109, these parameters The PM collection rate used for estimating the PM accumulation amount is changed accordingly.

  Thereafter, the process proceeds to step 110, and the current PM deposition amount (for example, the PM deposition amount per predetermined time) is estimated (calculated) by the above equation (1) using the sensor detected PM amount and the PM collection rate. Thereafter, the process proceeds to step 111, where the current PM deposition amount is added to the previous accumulated value of the PM deposition amount, and the PM accumulated amount up to this time is obtained.

  In the present embodiment described above, the PM accumulation amount of the single plug filter 31 is estimated based on the PM amount detected by the PM sensor 32 (sensor detected PM amount) and the PM collection rate of the single plug filter 31. Yes. Since a predetermined correlation is established among the PM accumulation amount, the sensor detection PM amount, and the PM collection rate, the PM accumulation amount is estimated (calculated) by using the sensor detection PM amount and the PM collection rate. Can do. At this time, since the PM accumulation amount can be estimated without using the differential pressure across the single plug filter 31, the PM accumulation amount is accurate even when the PM accumulation amount is small and the differential pressure across the single plug filter 31 is small. It can be estimated well. In addition, since there is no need to provide a differential pressure sensor for detecting the differential pressure across the single plug filter 31, it is possible to avoid an increase in system cost and complexity.

  Further, in this embodiment, considering that the PM collection rate changes according to parameters such as the PM deposition amount, the exhaust gas flow rate, the exhaust pressure, the exhaust gas temperature, the ash deposition amount, etc., according to these parameters. The PM collection rate used for estimating the PM accumulation amount is changed. Accordingly, the PM collection rate used for estimating the PM deposition amount is changed in accordance with the change of the PM collection rate according to the PM deposition amount, the exhaust gas flow rate, the exhaust pressure, the exhaust gas temperature, the ash deposition amount, and the like. It can be changed and set to an appropriate value, and the PM deposition amount estimation accuracy can be improved.

  In the above embodiment, the PM collection rate used for estimating the PM deposition amount is changed according to all of the PM deposition amount, the exhaust gas flow rate, the exhaust pressure, the exhaust gas temperature, and the ash deposition amount. However, the present invention is not limited to this, and the PM collection rate used for estimating the PM deposition amount is changed according to one or more of the PM deposition amount, the exhaust gas flow rate, the exhaust pressure, the exhaust gas temperature, and the ash deposition amount. You may do it.

  In the above embodiment, the present invention is applied to a system including a single plug filter having a structure in which the inlet sides of some cells are closed and the outlet sides of all cells are opened. However, the present invention is not limited to this. The present invention may be applied to a system including a single plug filter having a structure in which the inlet side of some cells is closed and the outlet side of some of the remaining cells (cells whose inlet side is opened) is closed. . Alternatively, a single plug filter having a structure in which the outlet side of some cells is closed and the inlet side of all cells is opened, or the remaining cells (cells in which the outlet side is opened) with the outlet side of some cells closed The present invention may be applied to a system including a single-ended filter having a structure in which the inlet side of some of the cells is closed. In short, the present invention can be applied to any system provided with a single plug filter having a structure in which both the inlet side and the outlet side of some cells are open.

  In the above embodiment, the present invention is applied to a system equipped with an in-cylinder injection gasoline engine. However, the present invention is not limited to this, and a diesel engine or an intake port injection gasoline may be used as long as the system includes a single plug filter. Even a system equipped with an engine can be implemented by applying the present invention.

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 30 ... ECU (estimating means), 31 ... Single plug filter, 32 ... PM sensor, 33 ... Cell

Claims (6)

A filter that collects particulate matter (hereinafter referred to as “PM”) in the exhaust gas of the internal combustion engine (11), and is a part of a plurality of cells (33) provided in the filter. A structure having at least one cell in which the inlet side is closed and the outlet side is opened among the remaining cells, or at least one cell in which the outlet side of some of the cells is closed and the inlet side is opened A single-ended filter (31) having a structure comprising:
A PM sensor (32) for detecting the amount of PM in the exhaust gas that has passed through the single plug filter (31);
Estimating means (30) for estimating the amount of PM deposited on the single plug filter (31) based on the amount of PM detected by the PM sensor (32) and the PM collection rate of the single plug filter (31). A control device for an internal combustion engine.   The control device for an internal combustion engine according to claim 1, wherein the estimating means (30) changes a PM collection rate used for estimating the PM accumulation amount in accordance with the PM accumulation amount.   The said estimation means (30) changes PM collection rate used for estimation of the said PM deposition amount according to the flow volume of the exhaust gas which passes through the said one end plug filter (31), The characterized by the above-mentioned. The control apparatus of the internal combustion engine described in 1.   The said estimation means (30) changes the PM collection rate used for estimation of the said PM deposit amount according to the exhaust pressure of the upstream of the said single plug filter (31), The Claim 1 thru | or 3 characterized by the above-mentioned. The control apparatus of the internal combustion engine in any one.   The estimation means (30) sets the PM collection rate used for the estimation of the amount of accumulated PM, the temperature of the exhaust gas flowing into the single plug filter (31), and the temperature of the exhaust gas flowing out of the single plug filter (31). 5. The control device for an internal combustion engine according to claim 1, wherein the control device is changed according to at least one of the temperature of the single plug filter (31).   The said estimation means (30) changes PM collection rate used for estimation of the said PM deposit amount according to the ash deposit amount of the said one piece filter (31), The one of Claims 1 thru | or 5 characterized by the above-mentioned. The control apparatus of the internal combustion engine described in 1.

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