JP2017198160A - Filter regeneration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter regeneration control device capable of securing cleanliness of exhaust gas by performing filter regeneration processing appropriate to an operating state of an internal combustion engine.SOLUTION: An ECU 31 is mounted to a vehicle 100 including: a DPF 22 for collecting PMs in exhaust gas; a fuel injection valve 12 for injecting fuel into a combustion chamber 13 of the engine 11; and a fuel addition valve 27 for adding fuel to exhaust gas flowing into a catalyst 21 upstream of the DPF. The ECU estimates the accumulation amount of PMs accumulated in the DPF, and increases an exhaust gas temperature to regenerate the DPF by executing injection processing for injecting fuel from the fuel injection valve into the combustion chamber also after main injection is performed or addition processing for adding fuel from the fuel addition valve into the exhaust gas when the accumulation amount reaches equal to or larger than a first threshold value in a memory 32 in accordance with the operating state of the engine and by executing the addition processing when the accumulation amount reaches equal to or larger than a second threshold value that is smaller than the first threshold value in the memory.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a filter regeneration control device that executes a regeneration process of a filter that purifies exhaust gas from an internal combustion engine.

  2. Description of the Related Art An internal combustion engine that outputs power by burning fuel is often used to provide a device that removes and purifies harmful substances contained in exhaust gas after combustion. For example, in diesel engines, exhaust purification devices such as catalysts and filters (DPF described later) are installed to purify unburned fuel, NOx, SOx, and particulate matter (hereinafter referred to as PM) contained in the exhaust. It is widely used to do.

  Since the performance of this exhaust gas purification device is lowered according to the processing amount of exhaust gas, it is necessary to appropriately perform regeneration processing. In particular, a filter that removes particulate matter generated in a diesel engine will cause pressure loss in the exhaust and hinder combustion if the collected PM accumulates more than a certain amount. Here, the filter that removes the particulate matter has a filter temperature that becomes excessively high during the regeneration process by PM combustion described later when the collected PM becomes a certain amount or more. It is necessary to do it appropriately.

  Therefore, in an apparatus such as a diesel engine vehicle equipped with this filter, PM containing carbon as a main component is burned by causing the catalyst for purifying the exhaust gas of the internal combustion engine to process the unburned fuel and raising the exhaust gas temperature. It has been developed to execute a reproduction process (see Patent Document 1). This patent document 1 discloses an in-cylinder post-injection process for injecting new fuel into a cylinder after combustion of an internal combustion engine for the purpose of mixing unburned fuel into exhaust gas flowing into a catalyst, An exhaust passage fuel addition process is described which is performed by installing a fuel addition valve for adding new fuel upstream of the catalyst that does not return into the cylinder. Note that, as described in Patent Document 1, an internal combustion engine may have a so-called EGR function that improves a combustion efficiency by recirculating a part of exhaust gas into a cylinder.

JP 2010-116817 A

  However, in such a filter regeneration control device, when the in-cylinder post-injection process for injecting unburned fuel into the exhaust by injecting new fuel into the cylinder of the internal combustion engine is performed, the engine oil Unburned fuel is mixed in and diluted.

  On the other hand, the engine regeneration can be prevented by performing the filter regeneration process using the fuel addition valve installed upstream of the catalyst, but the injection at the fuel addition valve is less than the post injection, There is a demerit that the injected fuel is difficult to uniformly mix with the exhaust gas, and depending on the injection timing, an additional device for uniformly mixing the fuel is required. In addition, in the fuel addition valve, it is necessary to inject more fuel than in the post-injection, or when the exhaust gas temperature does not rise sufficiently during low-load operation where the exhaust gas flow rate is low, the PM accumulated in the filter Can't burn.

  Therefore, the present invention performs filter regeneration processing appropriate for the operating state of the internal combustion engine to greatly reduce the dilution of oil due to post-injection, and to re-filter the filter while avoiding the occurrence of filter pressure loss. An object of the present invention is to provide a filter regeneration control device capable of preventing an excessive temperature rise during processing.

  One aspect of the invention of a filter regeneration control device that solves the above problems is a filter that is installed in an exhaust passage and collects particulate matter contained in exhaust gas, and a fuel injection valve that injects fuel into a cylinder of an internal combustion engine And a fuel addition valve for adding fuel to the exhaust passage upstream of the installation location of the filter, and trapping the filter by raising the temperature of the exhaust gas introduced into the filter. A filter regeneration control device that regenerates the filter by burning and removing the collected particulate matter, an acquisition unit that obtains an accumulation amount of the particulate matter in the filter, and a predetermined particulate matter The first threshold value of the accumulation amount and the second threshold value of the accumulation amount smaller than the first threshold value are set in advance, and after the main injection into the cylinder at the time of power output of the internal combustion engine, One of a cylinder post-injection process for injecting fuel into the cylinder from the fuel injection valve and an exhaust passage fuel addition process for adding fuel from the fuel addition valve to the exhaust passage. A regeneration control unit that regenerates the filter by selecting and executing based on the above, and the regeneration control unit is configured such that the accumulated amount of the particulate matter acquired by the acquisition unit is equal to or greater than the first threshold value. In addition, at least one of the in-cylinder post-injection process and the exhaust passage fuel addition process selected based on the operating state of the internal combustion engine is executed, and the accumulated amount of the particulate matter acquired by the acquisition unit is the first When the exhaust passage fuel addition process selected based on the operating state of the internal combustion engine is performed when the threshold value is less than one threshold value and greater than or equal to the second threshold value, the accumulated amount of the particulate matter acquired by the acquisition unit is If it is less than the serial second threshold value, the in-cylinder post injection process and the none of the execution of the exhaust passage fuel addition processing is configured to limit.

  Thus, according to one aspect of the present invention, in-cylinder post injection processing and exhaust passage fuel addition selected based on the operating state of the internal combustion engine when the amount of particulate matter accumulated in the filter is equal to or greater than the first threshold value. When at least one of the processes is performed and the amount of accumulation is less than the first threshold and greater than or equal to the second threshold, the exhaust passage fuel addition process selected based on the operating state of the internal combustion engine is performed, and the amount of accumulation is When it is less than two threshold values, execution of both the in-cylinder post injection process and the exhaust passage fuel addition process is limited.

  For this reason, when the accumulation amount of the particulate matter is equal to or greater than the first threshold value, one or both of the in-cylinder post injection and the exhaust passage fuel addition processing is forcibly selected and executed in a situation appropriate for the operating state of the internal combustion engine. The Further, when the accumulation amount is less than the first threshold value and greater than or equal to the second threshold value, it is selectively executed when the exhaust passage fuel addition process can be executed for the operating state of the internal combustion engine. Further, when the accumulation amount is less than the second threshold value, the regeneration process of the filter is postponed.

  Therefore, the filter regeneration process is not repeated despite the fact that the amount of particulate matter deposited is less than the second threshold and the necessity is low. The filter can be regenerated by repeatedly selecting and executing an exhaust passage fuel addition process in which no oil dilution occurs. Further, when the accumulation amount of the particulate matter reaches a first threshold value that is larger than the second threshold value for some reason, the in-cylinder post injection processing and the exhaust passage fuel addition processing appropriate for the operating state of the internal combustion engine are performed. The filter can be regenerated by at least one of them.

  As a result, filter regeneration processing according to the operating state of the internal combustion engine is executed as appropriate based on the amount of particulate matter deposited, greatly reducing oil dilution due to post-injection, and generating pressure loss due to filter clogging. It is possible to prevent an excessive increase in temperature during reprocessing of the filter while preventing the above.

FIG. 1 is a diagram illustrating an example of a vehicle equipped with a filter regeneration control device according to an embodiment of the present invention, and is a conceptual diagram illustrating a configuration of a main part of the vehicle. FIG. 2 is a graph for explaining the operating state of the engine mounted on the vehicle. FIG. 3 is a flowchart illustrating a control process for regenerating the filter provided in the engine.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 3 are views showing an example of a vehicle equipped with a filter regeneration control device according to an embodiment of the present invention.

  In FIG. 1, a vehicle 100 travels with an internal combustion engine 11 as a power source. The engine 11 of this embodiment is a compression ignition type diesel engine. The engine 11 mixes fuel injected by the fuel injection valve 12 into the combustion chamber (in-cylinder) 13 with intake air (new air) drawn from the intake passage 14 and burns the mixture by self-igniting. Further, the engine 11 discharges the exhaust after combustion scavenged from the combustion chamber 13 into the outside air from the exhaust passage 15.

  The engine 11 is provided with a turbocharger 16 so as to straddle the intake passage 14 and the exhaust passage 15. The turbocharger 16 rotates the compressor 16b in the intake passage 14 with the rotational force of the turbine 16a rotated by the exhaust gas in the exhaust passage 15 to rotate the intake air taken in through the intake passage 14 into the combustion chamber 13. It is designed to be supercharged by pushing it in. In addition, a throttle valve 17 is installed in the intake passage 14 on the downstream side of the compressor 16b of the turbocharger 16, and the intake air amount is adjusted by adjusting the opening and closing of the throttle valve 17.

  The engine 11 is provided with an EGR (Exhaust Gas Recirculation) passage 18 that allows the intake passage 14 and the exhaust passage 15 to communicate with each other. The engine 11 has an EGR function that improves combustion efficiency by returning a part of the exhaust gas in the exhaust passage 15 as EGR gas to the intake passage 14 via the EGR passage 18 and recirculating it. The EGR passage 18 is provided with an EGR valve 19 for adjusting the flow rate of EGR gas. The EGR valve 19 is opened and closed to adjust the flow rate of the EGR gas by adjusting the opening amount.

  The engine 11 also has a catalyst 21 for purifying the exhaust passage 15 by occluding or oxidizing and reducing harmful substances such as unburned fuel and NOx remaining in the exhaust, and PM (particulate matter) generated in the diesel engine. And a diesel particulate filter (hereinafter referred to as DPF: diesel particulate filter) 22 are disposed as an exhaust purification device.

  The catalyst 21 is installed in the exhaust passage 15 located on the downstream side of the turbine 16 a of the turbocharger 16. The catalyst 21 performs a purification process to remove unburned fuel and NOx and other harmful substances contained in the inflowing exhaust gas, and burns the unburned fuel with oxygen in the exhaust gas. A regeneration process such as reducing and releasing the stored NOx and the like is appropriately performed.

  The DPF 22 is installed in the exhaust passage 15 located on the downstream side of the catalyst 21. The DPF 22 performs a purification process for collecting PM contained in the exhaust gas flowing in through the catalyst 21, and introduces high-temperature exhaust gas whose temperature has been raised by combustion in the catalyst 21. Thus, the regeneration process for burning PM is appropriately performed.

  Incidentally, the engine 11 is controlled in an integrated manner by an ECU (Electronic Control Unit) 31 mounted on the vehicle 100 and outputs a desired drive torque as rotational power. The ECU 31 performs a control process according to various information by executing a control program stored in the memory 32 provided. In addition, the ECU 31 appropriately starts a counter (timer) 33 to time the time used in various control processes, for example, the timing adjustment of a specific process required according to the elapsed time, etc. Is to be performed as appropriate.

  The ECU 31 includes an accelerator opening sensor 35 that detects the amount of depression of an accelerator pedal (not shown), a crank position sensor 36 that detects the rotation speed (rotation speed) of the engine 11, and an upstream side of the compressor 16b of the turbocharger 16. An air flow meter 37 that detects the intake fresh air amount (intake amount) of fresh air that is installed and circulated in the intake passage 14 is connected so as to be able to receive a sensor signal. The ECU 31 derives a target torque as rotational power to be output from the engine 11 based on the sensor signals of the accelerator opening sensor 35 and the crank position sensor 36, and circulates in the intake passage 14 from the sensor signal of the air flow meter 37. Get the intake air amount. The ECU 31 optimizes the fuel injection amount by the fuel injection valve 12 based on the target torque and the intake air amount, and adjusts the opening and closing of the throttle valve 17 and the EGR valve 19 and the driving of the turbocharger 16 to adjust the intake passage 14. A control process for optimizing the amount of intake air through the engine is executed.

  As a result, the ECU 31 can efficiently drive the engine 11 under operating conditions with a small burden on the catalyst 21 and the DPF 22, and outputs desired rotational power from the engine 11 while purifying exhaust from the exhaust passage 15. 100 can be run.

  In addition, in the ECU 31, a control program for executing regeneration processing of the catalyst 21 and the DPF 22 is stored in the memory 32 as appropriate in order to ensure the processing capacity of the catalyst 21 and the DPF 22 to a certain level or more.

  For example, the ECU 31 controls driving of a fuel system such as the fuel injection valve 12 and an intake system such as the throttle valve 17, the EGR valve 19, and the turbocharger 16 so as to output rotational power for traveling from the engine 11. Then, a main injection process is performed in which fuel or intake air is supplied into the combustion chamber 13 and burned. The ECU 31 is configured to execute an in-cylinder post injection process in which a small amount of fuel corresponding to the driving state of the engine 11 is injected from the fuel injection valve 12 at a retarded timing after the main injection process.

  Thereby, the ECU 31 can newly add unburned fuel to the exhaust gas after combustion by the execution of the in-cylinder post-injection process and allow the unburned fuel to flow into the catalyst 21. The regeneration process can be executed by burning an air-fuel mixture with oxygen.

  Further, the engine 11 is provided with a fuel addition valve 27 that injects the unburned fuel so as to be newly added to the exhaust passage 15 downstream of the turbine 16 a of the turbocharger 16. The ECU 31 is connected to the ECU 31 so that an air-fuel ratio sensor 25 installed in the exhaust passage 15 on the downstream side of the catalyst 21 and detecting the air-fuel ratio in the mixture of unburned fuel and air in the exhaust can receive the sensor signal. Has been.

  This ECU 31 is connected to the exhaust passage 15 from the fuel injection valve 12 and the fuel addition valve 27 based on the driving state (driving condition) of the engine 11 controlled to output the target torque and the sensor signal of the air-fuel ratio sensor 25. An exhaust passage fuel addition process for adding a small amount of unburned fuel to the exhaust inside is performed.

  As a result, the ECU 31 can newly add unburned fuel to the exhaust gas after combustion and allow it to flow into the catalyst 21 even when the exhaust passage fuel addition process is executed. The regeneration process can be executed by burning the air-fuel mixture with the residual oxygen.

  In this way, by the in-cylinder post injection process or the exhaust passage fuel addition process, the DPF 22 is fed with the high-temperature exhaust gas whose temperature has been raised by the combustion in the catalyst 21, and the collected PM is removed by combustion and regenerated. . That is, the ECU 31 is injected (added) from the in-cylinder post-injection process (hereinafter also simply referred to as injection process) in which unburned fuel injected from the fuel injection valve 12 flows into the catalyst 21 and the fuel addition valve 27. A regeneration control unit that executes at least one of exhaust passage fuel addition processing (hereinafter also simply referred to as addition processing) for causing unburned fuel to flow into the catalyst 21 and introduces high-temperature exhaust gas from the catalyst 21 into the DPF 22 for regeneration. Is configured.

  The ECU 31 executes control processing for regenerating the DPF 22 by in-cylinder post injection processing or exhaust passage fuel addition processing in accordance with a control program in the memory 32 in accordance with the driving state of the engine 11.

  Specifically, the ECU 31 estimates and acquires the PM accumulation amount accumulated in the DPF 22 based on the driving conditions such as the integrated fuel injection amount of the engine 11 from the previous regeneration process, and stores the estimated accumulation amount in the memory. By comparing with a first threshold value and a second threshold value preset in 32, the regeneration process of the in-cylinder post-injection process or the exhaust passage fuel addition process is appropriately executed. That is, the memory 32 constitutes a setting unit, and the ECU 31 constitutes an acquisition unit.

  Here, the amount of PM accumulated is a map created from the amount of PM generated according to various conditions such as the rotational speed, intake air amount, valve opening / closing timing as well as the driving conditions of the engine 11, for example, the fuel injection amount. Or an arithmetic expression incorporating a valid parameter.

  Further, as the first threshold value, the limit value of the PM accumulation amount that must be immediately regenerated by the DPF 22, in other words, the DPF 22 generates pressure loss due to PM accumulation, or the temperature rise due to combustion during the regeneration process causes the DPF 22 In the memory 32, a value smaller than the PM accumulation amount that may cause damage such as cracks is set in the memory 32. Further, as the second threshold value, a value that is smaller than the first threshold value, for example, a value that allows the engine 11 to continue to be driven for at least two hours before reaching the first threshold value is stored in the memory 32. Is set to

  For example, in the case of the engine 11 having a predetermined output capacity, when the PM accumulation amount of the first threshold is 15 g, the PM accumulation amount of the second threshold is 13 g, and the difference is about 2 g. It may be set so that driving at a low load and a low rotation can be continued for about 5 hours before reaching the first threshold value after reaching. Alternatively, as the second threshold value, a value smaller than the first threshold value may be set to such an extent that the PM collection capability does not become insufficient even if the regeneration process of the DPF 22 is skipped a predetermined number of times.

  The engine 11 stores engine oil in order to smoothly move a piston (not shown) up and down by combustion (explosion) in the combustion chamber 13 of a mixture of fuel and intake air. Therefore, in the engine 11, depending on the timing of fuel injection into the combustion chamber 13, the injected fuel is mixed into the engine oil and diluted. In order to prevent dilution of the engine oil, for example, in the control program of the ECU 31, various measures are taken such as devising the timing of fuel injection from the fuel injection valve 12.

  Here, in the exhaust passage fuel addition processing executed by the ECU 31, unburned fuel is added directly from the fuel addition valve 27 to the exhaust passage 15 downstream of the turbine 16a (EGR passage 18) of the turbocharger 16 to thereby form the catalyst 21. To flow into. For this reason, in this addition process, since fuel is not injected into the combustion chamber 13, the dilution of the engine oil does not occur.

  However, in this exhaust passage fuel addition process, as shown in region A of FIG. 2, when the exhaust temperature is low in an operating state where the engine 11 is rotating at a low load and low speed with little fuel injection, the exhaust passage Even if unburned fuel is added to 15, it cannot be efficiently burned by the catalyst 21, and cannot be uniformly mixed with exhaust gas. For this reason, in this addition process, unevenness in combustion occurs depending on the operating state of the engine 11, and high-quality regeneration process may not be executed.

  On the other hand, in the in-cylinder post-injection process executed by the ECU 31, unburned fuel in the exhaust gas scavenged from the combustion chamber 13 after the main injection, even in the operating state of the engine 11 in the region A shown in FIG. Is injected. For this reason, in this injection process, the exhaust temperature is high, and the unburned fuel is effectively mixed with the exhaust gas, thereby causing incomplete combustion and uneven combustion as in the exhaust passage fuel addition process. The possibility of being incomplete is low.

  However, in this in-cylinder post-injection process, unburned fuel is injected from the fuel injection valve 12 after main injection and mixed into the exhaust gas from the combustion chamber 13. Therefore, in this injection process, unburned fuel tends to enter the engine oil side from the combustion chamber 13 and cause dilution.

  Therefore, when it is necessary to execute the regeneration process of the DPF 22, the ECU 31 of the present embodiment preferentially executes the exhaust passage fuel addition process in the region B shown in FIG. 2 according to the operating state of the engine 11. In the region A shown in FIG. 2, the in-cylinder post injection process is executed. When this injection process is executed at the timing of using the EGR function, the EGR valve 19 is closed to avoid (limit) the execution of the EGR function.

  Specifically, the ECU 31 executes the regeneration control process for the DPF 22 shown in the flowchart of FIG. 3 in accordance with the control program in the memory 32. When the drive control of the engine 11 is started, the ECU 31 regenerates the DPF 22. Control processing is processed in parallel.

  First, as shown in FIG. 3, the ECU 31 reads the estimated accumulation amount of PM accumulated after the previous regeneration process of the DPF 22 from the memory 32 and temporarily holds it (step S <b> 11), and various driving of the engine 11. An operation state corresponding to the conditions is acquired (step S12), and a calculation process is performed to estimate the amount of PM accumulated in addition to the PM accumulation amount (step S13), and the PM amount is added to calculate the PM accumulation amount. Update (step S14).

  Next, the ECU 31 checks whether or not the PM accumulation amount has reached or exceeded the first threshold value in the memory 32 (step S15). If not, the PM accumulation amount is further stored in the memory 32. It is confirmed whether or not the second threshold value has been reached (step S16). If not, the process returns to step S12 and the same processing is repeated.

  In step S16, when the ECU 31 confirms that the PM accumulation amount has reached the second threshold value in the memory 32, the operation shown in the region B of FIG. 2 in which the engine 11 can execute the exhaust passage fuel addition process. It is confirmed whether or not the state is in the state (step S17). When the region A is not the region B and cannot be executed, the process returns to the step S12 and the same processing is repeated.

  In step S17, when the ECU 31 confirms that the engine 11 is in the operating state of the region B where the exhaust passage fuel addition process can be performed, unburned fuel is injected from the fuel addition valve 27 at a predetermined timing. A regeneration process for adding to the exhaust gas in the exhaust passage 15 flowing into the catalyst 21 is executed (step S18).

  Thereafter, the ECU 31 resets the PM accumulation amount held in the memory 32 (step S19), and once ends the regeneration control process, the same process is repeated again from step S11 at a predetermined timing.

  As a result, when the high-temperature exhaust gas whose temperature has been raised by the catalyst 21 flows in the DPF 22, the collected PM is burned and removed and regenerated, and the PM collecting ability is restored. At this time, the ECU 31 performs the exhaust passage fuel addition process even when the PM accumulation amount of the DPF 22 is less than the second threshold value that does not require the regeneration process or when the PM 31 is greater than or equal to the second threshold value. When it is impossible to execute, the execution of the regeneration process of the DPF 22 can be postponed, and it is possible to avoid forcibly performing the regeneration process by the in-cylinder post injection process.

  On the other hand, in step S15, when the ECU 31 confirms that the PM accumulation amount has reached the first threshold value in the memory 32, the region shown in FIG. 2 in which the engine 11 can execute the exhaust passage fuel addition process. It is confirmed whether or not the operation state is B (step S21). If the operation state is executable, unburned fuel is injected from the fuel addition valve 27 at a predetermined timing as in step S18. Then, a regeneration process for adding to the exhaust gas in the exhaust passage 15 flowing into the catalyst 21 is executed (step S22).

  Thereafter, the ECU 31 proceeds to step S19, resets the PM accumulation amount held in the memory 32, once ends this regeneration control process, and then repeats the same process from step S11 again at a predetermined timing.

  Further, in step S21, when the ECU 31 confirms that the engine 11 is not in the operation state of the region B shown in FIG. 2 where the exhaust passage fuel addition process can be performed (the region A cannot be performed), the main injection is performed. A regeneration process is performed by an in-cylinder post-injection process in which unburned fuel is injected into the combustion chamber 13 from the fuel injection valve 12 at a predetermined timing and mixed with the exhaust gas flowing into the catalyst 21 (step S23).

  Thereafter, the ECU 31 proceeds to step S19, resets the PM accumulation amount held in the memory 32, once ends this regeneration control process, and then repeats the same process from step S11 again at a predetermined timing.

  As a result, when the high-temperature exhaust gas whose temperature has been raised by the catalyst 21 flows in the DPF 22, the collected PM is burned and removed and regenerated, and the PM collecting ability is restored. At this time, the ECU 31 preferentially executes an exhaust passage fuel addition process that can be executed when the operating state of the engine 11 is in the region B of FIG. When the operating state is the region A in FIG. 2, the in-cylinder post-injection that can be executed can be executed to regenerate the DPF 22.

  If the regeneration control process is terminated after the ignition is turned off before the PM accumulation amount in the memory 32 is reset in step S19, the PM accumulation amount before the reset is stored in the memory 32. Will be retained.

  As described above, in the ECU 31 of the present embodiment, the exhaust passage fuel addition process is performed at the timing when the accumulated amount of PM collected by the DPF 22 reaches the second threshold value when the engine 11 is operating in the region B of FIG. The purification ability of the DPF 22 can be ensured by repeatedly executing it. The ECU 31 executes the in-cylinder post-injection process at an extremely rare timing when the operating state of the engine 11 in the region A of FIG. 2 continues and the PM accumulation amount of the DPF 22 becomes equal to or greater than the first threshold value. As a result, the purification ability of the DPF 22 can be secured.

  Therefore, it is possible to execute the filter regeneration process of the DPF 22 that is appropriate for the operating state of the engine 11, and the DPF 22 can continue clean exhaust without causing pressure loss due to PM accumulation.

  Moreover, in this embodiment, although the case where it applies to a diesel engine is demonstrated as an example, it cannot be overemphasized that it is applicable not only to this but a gasoline engine, for example.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

11 Engine (Internal combustion engine)
12 Fuel Injection Valve 13 Combustion Chamber 14 Intake Passage 15 Exhaust Passage 17 Throttle Valve 18 EGR Passage 19 EGR Valve 21 Catalyst 22 DPF (Filter)
25 Air-fuel ratio sensor 27 Fuel addition valve 31 ECU (acquisition unit, regeneration control unit, filter regeneration control device)
32 Memory (setting part)
35 Accelerator opening sensor 36 Crank position sensor 37 Air flow meter 100 Vehicle

Claims (1)

A filter installed in the exhaust passage to collect particulate matter contained in the exhaust;
A fuel injection valve for injecting fuel into a cylinder of the internal combustion engine;
A fuel addition valve for adding fuel to the exhaust passage upstream of the filter installation location;
And a filter regeneration control device that regenerates the filter by burning and removing the particulate matter trapped in the filter by increasing the temperature of the exhaust gas introduced into the filter. And
An acquisition unit for acquiring a deposition amount of the particulate matter in the filter;
A setting unit in which a first threshold value of the predetermined accumulation amount of the particulate matter and a second threshold value of the accumulation amount smaller than the first threshold value are set in advance;
In-cylinder post injection processing for injecting fuel from the fuel injection valve into the cylinder after main injection into the cylinder at the time of power output of the internal combustion engine, and adding fuel from the fuel addition valve to the exhaust passage A regeneration control unit for regenerating the filter by selecting and executing one of the exhaust passage fuel addition processing based on the operating state of the internal combustion engine;
The regeneration control unit includes the in-cylinder post-injection process and the exhaust gas selected based on an operating state of the internal combustion engine when the accumulation amount of the particulate matter acquired by the acquisition unit is equal to or greater than the first threshold value. Performing at least one of the passage fuel addition processes;
When the acquisition amount of the particulate matter acquired by the acquisition unit is less than the first threshold and greater than or equal to the second threshold, the exhaust passage fuel addition process selected based on the operating state of the internal combustion engine is executed. ,
A filter regeneration control device that restricts execution of both the in-cylinder post-injection process and the exhaust passage fuel addition process when the accumulation amount of the particulate matter acquired by the acquisition unit is less than the second threshold value.

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