JP7052717B2 - Internal combustion engine control device - Google Patents

Description

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

Generally, in a diesel engine (internal combustion engine), a filter for collecting particulate matter (PM: Particulate Matter) contained in exhaust gas is provided in an exhaust passage to suppress the release of particulate matter into the atmosphere. In this filter, if the accumulated amount of collected PM increases, the pressure loss of the filter increases, which may lead to a decrease in the output of the diesel engine and a deterioration in fuel efficiency.

The exhaust gas purification device for an in-vehicle diesel engine described in Patent Document 1 raises the temperature of exhaust gas by reacting fuel injected by post-injection with an oxidation catalyst in an idling state. Then, the heated exhaust gas is guided to the filter, and the regeneration process (manual regeneration process) for burning and removing the particulate matter accumulated in the filter is executed. It is known that the regeneration process of the filter can be completed earlier by raising the temperature of the exhaust gas flowing into the filter and burning the particulate matter faster.

Japanese Unexamined Patent Publication No. 2008-20273

By the way, if a large amount of fuel is injected by post-injection, a part of the fuel adhering to the cylinder may be mixed with the lubricating oil in the oil pan together with the lubricating oil. If the lubricating oil is diluted due to such mixing of fuel, the lubricating and cooling actions of the lubricating oil are deteriorated, which may lead to seizure and wear of various parts of the internal combustion engine.

Further, the exhaust gas purification device for an in-vehicle diesel engine described in Patent Document 1 requires that the accelerator be not operated as a requirement for carrying out the manual regeneration process, but the internal combustion engine can operate the accelerator during the manual regeneration. There is also. In this case, the driver opens the accelerator to increase the rotation speed of the internal combustion engine in order to finish the regeneration process earlier.

However, if the accelerator is opened and the rotation speed of the internal combustion engine is increased too much, the post-injection amount increases too much, and a part of the fuel accompanying the post-injection may dilute the lubricating oil. In order to prevent this, when the number of revolutions exceeds a predetermined value, the post injection amount is reduced (post injection amount limit), and the temperature of the exhaust gas flowing into the filter does not rise as expected, resulting in the time required for the regeneration process. However, it may be longer than the target reproduction time, which is the target time for ending the reproduction process.

The present invention was devised in view of these points, and in a manual regeneration process in which particulate matter deposited on a filter is burned and incinerated by using post-injection, the accelerator is depressed to post. An object of the present invention is to provide a control device for an internal combustion engine capable of completing a manual regeneration process within a target regeneration time even when the injection amount is increased to a reduced rotation speed.

In order to solve the above problems, the first invention is an internal combustion engine in an internal combustion engine system having a filter for collecting particulate matter and an oxidation catalyst arranged on the upstream side of the filter in the exhaust path of the internal combustion engine. The control device detects the operating state of the internal combustion engine, and performs main injection to inject an amount of fuel corresponding to the detected operating state into the cylinder of the internal combustion engine. While controlling the engine, the internal combustion engine is controlled so as to be equal to or lower than a preset maximum rotation speed, and the control device is provided with the maximum rotation speed, which is the upper limit rotation speed of the internal combustion engine, or the maximum rotation speed. The maximum injection amount, which is the upper limit injection amount of the main injection corresponding to the number, is set, and the idling rotation speed is increased and the exhaust temperature is increased to burn and incinerate the particulate matter accumulated in the filter. The maximum rotation of manual regeneration based on the target regeneration time, which is the target time from the start of manual regeneration to the regeneration end amount or less of the particulate matter remaining in the filter. The number or the maximum injection amount for manual regeneration is set, and the control device sets the idling rotation speed to the target regeneration time when the manual regeneration instruction is input from the driver and the manual regeneration is started. The idling rotation speed increasing means for increasing the manual regeneration lower limit rotation speed set based on the above, and when the manual regeneration is started, the exhaust temperature is increased in the oxidation catalyst and deposited in the filter. A post-injection executing means that injects a post-injection for injecting fuel for burning and incinerating the particulate matter into the cylinder after the main injection, and an upper limit of the internal combustion engine when the manual regeneration is started. The rotation speed is changed to the manual regeneration maximum rotation speed set lower than the maximum rotation speed, or the upper limit injection amount of the main injection into the cylinder is set lower than the maximum injection amount. A control device for an internal combustion engine having an upper limit rotation limiting means for changing to the maximum manually regenerated injection amount.

The second invention is the control device for the internal combustion engine according to the first invention, and the injection amount of the post injection performed at the time of the manual regeneration is the injection amount according to the rotation speed of the internal combustion engine. In addition to being set, when the rotation speed of the internal combustion engine exceeds a preset post injection limit start rotation speed, the amount is set to decrease as the rotation speed of the internal combustion engine increases. The maximum manual regeneration speed or the maximum manual regeneration injection amount is an internal combustion engine control device set based on the injection amount of the post injection and the target regeneration time.

The third invention is the control device for the internal combustion engine according to the second invention, wherein the maximum manual regeneration rotation speed is equal to or higher than the post-injection limit start rotation speed and less than the maximum rotation speed. Or, the manual regeneration maximum injection amount is set to an injection amount equal to or more than the post-limit start injection amount, which is the injection amount corresponding to the post-injection limit start rotation speed, and less than the maximum injection amount. It is a control device for an internal combustion engine.

A fourth invention is a control device for an internal combustion engine according to the second or third invention, wherein the control device has particles deposited in the filter at least when the manual regeneration is not performed. A means for estimating the amount of accumulated matter that estimates the amount of the state substance, and a means for estimating the residual amount that estimates the residual amount of the particulate matter in the filter that has been reduced by combustion incineration when the manual regeneration is performed. An upper limit rotation limit changing means for changing the maximum manual regeneration speed or the maximum manual regeneration injection amount based on the elapsed time from the start of manual regeneration, the remaining amount, and the target regeneration time. It is a control device for an internal combustion engine.

According to the first invention, in the manual regeneration process by the driver, the regeneration process can be completed within the target reproduction time.

According to the second invention, in the manual regeneration process by the driver, the regeneration process can be completed within the target regeneration time, and the injection amount in the post injection can be reduced to prevent the lubricating oil from being diluted.

According to the third invention, even when the accelerator operation is performed, the reproduction process can be surely completed within the target reproduction time.

According to the fourth invention, since the regeneration process is performed by optimizing the maximum manual regeneration speed or the maximum manual regeneration injection amount based on the residual amount of particulate matter (PM) in the filter, the regeneration time can be further shortened.

It is a figure explaining an example of the configuration to which the control device of the internal combustion engine (engine) which concerns on embodiment is applied. It is a figure explaining the relationship between the regeneration process (without the accelerator operation of a driver) and the PM accumulation amount of a filter. It is a figure explaining the relationship between the regeneration process (with the accelerator operation of a driver), and the PM accumulation amount of a filter. It is a flowchart explaining the procedure of the reproduction processing of embodiment. It is a flowchart explaining the procedure of idling control processing. It is a flowchart explaining the procedure of the upper limit rotation speed control processing. It is a flowchart explaining the procedure of the upper limit injection amount control processing. It is a flowchart explaining the procedure of the filter deposition amount estimation processing. It is a flowchart explaining the procedure of a post-injection control process. It is a figure which shows the relationship between the engine speed and the regeneration process.

● [Overall configuration to which the control device of the internal combustion engine according to the embodiment is applied (Fig. 1)]
The overall configuration of the embodiment for carrying out the present invention will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a configuration to which a control device for an internal combustion engine according to an embodiment is applied. The internal combustion engine 10 is a diesel engine (hereinafter referred to as an engine). In the following description, the DPF 43 is a Diesel Particulate Filter (corresponding to a filter). Further, the description of the selective reduction catalyst or the like which is arranged in the exhaust passage on the downstream side of the DPF43 and detoxifies nitrogen oxides (NOx) is omitted.

As shown in FIG. 1, an exhaust gas purifying device 41 is provided in the exhaust passage (corresponding to the exhaust path) 12 of the internal combustion engine 10. Further, inside the exhaust gas purification device 41, an oxidation catalyst (DOC: Diesel Oxidation Catalyst) 42 and a DPF 43 are provided from the upstream side. The exhaust gas purification device 41 constitutes an exhaust gas passage and removes harmful substances contained in the exhaust gas while the exhaust gas passes from the upstream side to the downstream side. Here, the internal combustion engine 10 burns fuel and causes harmful substances such as particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HC) together with the exhaust gas. Discharge.

The oxidation catalyst 42 is made of a cell-shaped cylinder formed of a ceramic columnar or the like, and has a large number of through holes formed in the axial direction thereof, and the inner surface thereof is coated with a noble metal such as platinum (Pt). Then, the oxidation catalyst 42 oxidizes and removes carbon monoxide (CO), hydrocarbons (HC) and the like contained in the exhaust gas by passing the exhaust gas through a large number of through holes under a predetermined temperature.

The DPF43 is a honeycomb-structured cell-shaped cylinder formed in a columnar shape or the like by a porous member made of a ceramic material or the like and provided with a large number of small holes in the axial direction, and the small holes are alternately adjacent to each other. Different ends are closed by a sealing member. Then, the DPF 43 collects particulate matter (PM) by passing the exhaust gas flowing into each small hole from the upstream side through the porous material, and causes only the exhaust gas to flow out to the downstream side through the adjacent small hole. ..

An exhaust temperature detection device 36A (for example, an exhaust temperature sensor) is provided on the upstream side of the oxidation catalyst 42 (upstream side of the exhaust gas purification device 41). An exhaust temperature detection device 36B (for example, an exhaust temperature sensor) is provided on the downstream side of the oxidation catalyst 42 and on the upstream side of the DPF 43.

An exhaust temperature detection device 36C (for example, an exhaust temperature sensor) is provided on the downstream side of the DPF 43. Further, in the exhaust gas purification device 41, the differential pressure (pressure) between the exhaust pressure (corresponding to the pressure inside the exhaust pipe) on the downstream side of the oxidation catalyst 42 and the upstream side of the DPF 43 and the pressure inside the exhaust pipe on the downstream side of the DPF 43. A differential pressure detecting device 35 (for example, a differential pressure sensor) for detecting the difference) is provided.

The control device 50 includes a CPU (not shown), a storage means 40, an idling rotation speed increasing means 52, a post injection executing means 54, an upper limit rotation limiting means 56, an upper limit rotation limiting changing means 58, and an accumulation amount estimation. The means 60 and the residual amount estimation means 62 are provided. The CPU executes various arithmetic processes based on various programs and the like stored in the storage means 40. Further, the storage means 40 temporarily stores predetermined values used for each process, calculation results by the CPU, data input from each detection device, and the like, and data to be stored when the internal combustion engine 10 is stopped. And so on.

The control device 50 has a detection signal of the intake air flow rate detection device 31 (for example, an air flow meter) provided in the intake passage 11, a detection signal of the accelerator opening degree detection device 33, and a detection signal of the rotation detection device 34, respectively. It has been entered.

The control device 50 can detect the operating state of the internal combustion engine 10 based on the detection signals from these detection devices. Further, the control device 50 receives the detected operating state of the internal combustion engine 10 and the request from the driver based on the detection signal from the accelerator opening degree detecting device 33, and the cylinders of the internal combustion engine 10 are sent from the injectors 14A to 14D. It outputs a control signal that controls the amount of fuel injected into the engine. Then, the control device 50 calculates the fuel injection amount (g / s) per second injected from each of the injectors 14A to 14D and stores it in the storage means 40.

The intake air flow rate detection device 31 (for example, an intake air flow rate sensor) is provided in the intake passage 11 of the internal combustion engine 10 and outputs a detection signal according to the flow rate of the air sucked by the internal combustion engine 10 to the control device 50. The accelerator opening degree detecting device 33 (for example, the accelerator opening degree sensor) outputs a detection signal corresponding to the opening degree of the accelerator operated by the driver (that is, the load requested by the driver) to the control device 50. The rotation detection device 34 (for example, a rotation sensor) outputs, for example, a detection signal corresponding to the rotation speed of the crankshaft of the internal combustion engine 10 (that is, the engine rotation speed) to the control device 50.

Further, in the example shown in FIG. 1, the control device 50 has a warning lamp 15 prompting the driver to execute the manual reproduction process of the DPF 43 (filter), and a manual reproduction switch SW for instructing the driver to start the manual reproduction. And have. Further, the manual reproduction switch SW operates only while the driver is pressing, for example, and outputs a signal corresponding to ON / OFF to the control device 50. The warning lamp 15 and the manual reproduction switch SW are provided, for example, in the instrument panel of the vehicle.

The control device 50 controls the internal combustion engine 10 by injecting the amount of fuel corresponding to the detected operating state from the injectors 14A to 14D in the cylinder of the internal combustion engine to control the internal combustion engine 10, and also controls the internal combustion engine 10. The internal combustion engine 10 is controlled so as to be as follows.

The control device 50 is set with a maximum rotation speed, which is the upper limit rotation speed of the internal combustion engine 10, and a maximum injection amount, which is the upper limit injection amount of the main injection corresponding to the maximum rotation speed, to increase the idling rotation speed. At the same time, the exhaust temperature is raised to burn and incinerate the particulate matter (PM) accumulated in the DPF43 to regenerate the DPF43 (filter). After the manual regeneration is started, the particulate matter remaining in the filter is regenerated. The maximum manual regeneration speed and the maximum manual regeneration injection amount are set based on the target regeneration time, which is the target time until the end amount becomes less than or equal to the end amount. The target reproduction time is a predetermined reproduction time set in advance and is stored in the storage means 40.

The idling rotation speed increasing means 52 increases the idling rotation speed to the manual reproduction lower limit rotation speed set based on the target reproduction time when the manual reproduction instruction is input from the driver and the manual reproduction is started. Let me. The lower limit rotation speed for manual reproduction is a preset rotation speed and is stored in the storage means 40.

When the manual regeneration is started, the post injection executing means 54 injects fuel into the cylinder for raising the exhaust temperature in the oxidation catalyst 42 and burning and incinerating the particulate matter accumulated in the filter. The injection is injected after the main injection.

In the post-injection, the fuel injected from the injectors 14A to 14D undergoes an oxidation reaction with the oxygen remaining in the exhaust gas by the oxidation catalyst 42 and burns, and the exhaust gas temperature rises due to the heat generation thereof. When the temperature of the DPF 43 rises due to the high temperature exhaust gas and reaches a predetermined temperature or higher (for example, 600 ° C. or higher), the particulate matter (PM) deposited in the DPF 43 is burnt and incinerated. By maintaining such a state for a predetermined time, the particulate matter accumulated in the DPF43 is burned and removed, and the collecting function of the DPF43 that collects the particulate matter (PM) in the exhaust gas is restored. Can be (reproduced).

When the manual regeneration is started, the upper limit rotation limiting means 56 changes the upper limit rotation speed of the internal combustion engine to a manual regeneration maximum rotation speed set lower than the maximum rotation speed, or enters the cylinder (not shown). The upper limit injection amount of the main injection of is changed to the manual regeneration maximum injection amount set lower than the maximum injection amount. The maximum rotation speed and the maximum injection amount are predetermined values set in advance and are stored in the storage means 40.

The upper limit rotation limit changing means 58 is based on the elapsed time from the start of manual regeneration, the residual amount of particulate matter (PM) of DPF43 (filter), and the target regeneration time, and the maximum manual regeneration speed and Manual regeneration Change the maximum injection amount.

The deposit amount estimation means 60 estimates the amount of particulate matter deposited in the DPF43 (filter) at least when manual regeneration is not performed, and stores the estimated deposit amount as the filter PM deposit amount (g). Store in means 40. The residual amount estimating means 62 estimates the residual amount of particulate matter in the DPF 43 reduced by combustion incineration when manual regeneration is performed.

● [Manual reproduction processing of DPF43 (filter) (FIGS. 2 to 8)]
The manual regeneration process of the DPF43 (filter) will be described with reference to FIGS. 2 to 8. FIG. 2 is a diagram illustrating the relationship between the regeneration process (without accelerator operation by the driver) and the PM accumulation amount of the filter. FIG. 3 is a diagram illustrating the relationship between the regeneration process (with the accelerator operation of the driver) and the PM accumulation amount of the filter. FIG. 4 is a flowchart illustrating the procedure of the reproduction process of the embodiment.

The figures shown in the upper part of FIGS. 2 and 3 show the relationship between the amount of filtered PM deposited on the DPF43 (filter) and the time in the regeneration process. The manual regeneration upper limit deposit indicates the maximum acceptable filter PM deposit at which the DPF43 can maintain its function as a filter.

Further, Tmax is the time from the manual regeneration upper limit deposition to the regeneration end amount, and indicates the target regeneration time, which is the target processing time for ending the regeneration process. The reproduction end amount is stored in advance in the storage means 40 (see FIG. 1), and is a filter PM accumulation amount for determining that the control device 50 has completed the manual reproduction process.

Hereinafter, the procedure of the manual reproduction process will be described with reference to FIGS. 4 to 8. When the control device 50 (see FIG. 1) is activated, each process (reproduction process, idling control process, upper limit rotation speed control process) in FIGS. 4 to 8 is performed at a predetermined time interval (for example, a number [ms] interval). , Upper limit injection amount control process, filter deposit amount estimation process) are executed sequentially. Hereinafter, each step in FIG. 4 will be described in detail.

In step S005, when the control device 50 determines that the filter PM accumulation amount is larger than the warning determination value (Yes), the process proceeds to step S010, and it is determined that the filter PM accumulation amount is not larger than the warning determination value. (No) advances the process to step S065. The warning determination value is a threshold value in the filter PM accumulation amount that prompts the driver to perform manual regeneration processing, is a predetermined accumulation amount set in advance, and is stored in the storage means 40.

In step S010, the control device 50 turns on (ON) the warning lamp 15 (see FIG. 1), and proceeds to step S015.

In step S015, when the control device 50 determines that the reproduction processing execution flag is ON (Yes), the process proceeds to step S020, and when it is determined that the reproduction processing execution flag is not ON (No), the step Proceed to S060. The reproduction process execution flag is a flag indicating whether or not the reproduction process is executed, and is set to ON when the reproduction process is executed and OFF when the reproduction process is not executed. The flag.

In step S020, if the control device 50 determines that the reproduction release condition is satisfied (Yes), the process proceeds to step S070, and if it is determined that the reproduction release condition is not satisfied (No), the process proceeds to step S070. The process proceeds to step S025. In the control device 50, for example, the internal combustion engine (engine) is stopped, the vehicle is running, and the position of the shift lever (not shown) is a non-running position (for example, the stop position "P" or neutral. If any one of the conditions such as not being the position "N") is satisfied, it is determined that the reproduction release condition is satisfied.

In step S060, when the control device 50 determines that the manual reproduction switch SW (see FIG. 1) is ON (Yes), the process proceeds to step S020, and when it is determined that the manual reproduction switch SW is not ON (Yes). No) ends the process.

In step S025, the control device 50 calculates the PM incinerator amount and proceeds to the process in step S030. The control device 50 calculates the PM incinerator amount based on the post injection amount and the engine speed. The post-injection amount is a preset injection amount of fuel for post-injection, and is stored in the storage means 40. The post injection is executed by the SUB 500 (post injection control process) described later.

In step S030, the control device 50 estimates the residual amount (filter PM deposit amount-PM incineration amount) by the residual amount estimation means 62, stores it in the storage means 40 as a new filter PM deposit amount, and processes it in step S035. To proceed.

In step S035, the control device 50 sets the idling rotation speed to the manual regeneration lower limit rotation speed, and proceeds to the process in step S040. The engine speed is controlled to reach the lower limit of manual regeneration by SUB100 (idling control processing) described later. The lower limit rotation speed for manual reproduction is, for example, 1200 rpm as shown in FIG.

In step S040, the control device 50 calculates and sets (updates) the maximum manual regeneration rotation speed, and proceeds to the process in step S045. The engine speed is controlled by SUB200 (upper limit rotation speed setting process) described later so that the upper limit rotation speed is equal to or less than the maximum manual regeneration speed.

In step S045, the control device 50 calculates and sets (updates) the manual regeneration upper limit injection amount based on the maximum manual regeneration rotation speed, and proceeds to the process in step S050. The fuel injection amount is controlled to reach the target upper limit injection amount by the SUB 300 (upper limit injection amount control process) described later.

In step S050, if the control device 50 determines that the updated filter PM deposit amount is smaller than the regeneration end amount (Yes), the process proceeds to step S070, and the filter PM deposit amount is not smaller than the regeneration end amount. If it is determined (No), the process proceeds to step S055.

In step S055, the control device 50 sets the reproduction processing execution flag to ON and ends the processing.

In step S065, when the control device 50 determines that the reproduction processing execution flag is ON (Yes), the process proceeds to step S010, and when it is determined that the reproduction processing execution flag is not ON (No), the step Proceed to S070.

In step S070, the control device 50 turns off the warning lamp 15 and proceeds to step S075.

In step S075, the control device 50 sets the reproduction processing execution flag to OFF, stops the post injection (regeneration processing), and ends the processing.

● [Idling control process (SUB100) (Fig. 5)]
FIG. 5 is a flowchart illustrating a procedure of idling control processing. Hereinafter, each step will be described in detail. This process corresponds to the idling speed increasing means. The (existing process) means a process executed in the existing control of the internal combustion engine.

In step SUB 110, when the control device 50 determines that the reproduction processing execution flag is ON (Yes), the process proceeds to step SUB 130, and when it is determined that the reproduction processing execution flag is not ON (No), the step Proceed to SUB120.

In step SUB 120, the control device 50 sets the target idling rotation speed (existing processing) to the normal idling rotation speed, and proceeds to process in step SUB 140. The normal idling speed is the idling speed of the engine when the regeneration process is not performed, and is, for example, 700 rpm as shown in FIG.

In step SUB 130, the control device 50 sets the target idling rotation speed to the manual regeneration lower limit rotation speed, and proceeds to step SUB 140. The lower limit rotation speed for manual reproduction is, for example, 1200 rpm as shown in FIG.

In step SUB 140, the control device 50 controls the rotation speed of the internal combustion engine so that the (existing processing) idling rotation speed becomes the target idling rotation speed, and ends the processing.

● [Upper limit rotation speed control process (SUB200) (Fig. 6)]
FIG. 6 is a flowchart illustrating a procedure of the upper limit rotation speed control process. Hereinafter, each step will be described in detail. This process corresponds to the upper limit rotation limit changing means.

In step SUB 210, when the control device 50 determines that the reproduction processing execution flag is ON (Yes), the process proceeds to step SUB 230, and when it is determined that the reproduction processing execution flag is not ON (No), the step Proceed to SUB220.

In step SUB 220, the control device 50 sets the target upper limit rotation speed (existing processing) to the maximum rotation speed, and proceeds to process in step SUB 240. The maximum rotation speed is a preset upper limit rotation speed of the engine when the reproduction process is not performed, and is stored in the storage means 40. The maximum rotation speed is, for example, 2500 rpm as shown in FIG.

In step SUB230, the control device 50 sets the target upper limit rotation speed to the manual reproduction maximum rotation speed, and proceeds to the process in step SUB240. The maximum number of rotations for manual reproduction can be changed, and is an upper limit rotation speed for which an initial value is set in advance, and is stored in the storage means 40. The initial value of the maximum manual regeneration speed is, for example, 1800 rpm as shown in FIG.

In step SUB 240, the control device 50 controls the rotation speed of the internal combustion engine so that the upper limit rotation speed (existing processing) becomes the target upper limit rotation speed, and ends the processing.

● [Upper limit injection amount control process (SUB300) (Fig. 7)]
FIG. 7 is a flowchart illustrating a procedure of the upper limit injection amount control process. Hereinafter, each step will be described in detail. This process corresponds to the upper limit rotation limit changing means.

In step SUB 310, when the control device 50 determines that the reproduction processing execution flag is ON (Yes), the process proceeds to step SUB 330, and when it is determined that the reproduction processing execution flag is not ON (No), the step Proceed to SUB320.

In step SUB320, the control device 50 sets the target upper limit injection amount (existing processing) to the maximum injection amount, and ends the processing. The maximum injection amount is the upper limit injection amount of the engine when the regeneration process is not performed, and is stored in the storage means 40. As shown in FIG. 2, the maximum injection amount is an upper limit injection amount corresponding to, for example, 2500 rpm.

In step SUB330, the control device 50 sets the target upper limit injection amount to the manual regeneration maximum injection amount, and ends the process. The maximum manual regeneration injection amount is an upper limit injection amount obtained based on the maximum manual regeneration rotation speed and having an initial value set in advance, and is stored in the storage means 40. As shown in FIG. 2, the initial value of the maximum manual regeneration injection amount is the upper limit injection amount corresponding to, for example, 1800 rpm.

● [Filter deposition amount estimation process (SUB400) (Fig. 8)]
FIG. 8 is a flowchart illustrating the procedure of the filter deposition amount estimation process. Hereinafter, each step will be described in detail.

In step SUB410, the control device 50 estimates the amount of generated particulate matter (estimation of PM amount) according to the operating state of the (existing processing) internal combustion engine, and estimates the amount of particulate matter in the deposited amount. Is added to update the amount of accumulated filter PM, and the process is completed.

● [Post injection control process (SUB500) (Fig. 9)]
FIG. 9 is a flowchart illustrating the procedure of the post injection control process. Hereinafter, each step will be described in detail.

In step SUB510, when the control device 50 determines that the reproduction process execution flag is ON (Yes), the process proceeds to step SUB520, and when it is determined that the reproduction process execution flag is not ON (No), the process proceeds. To finish.

In step SUB520, the control device 50 calculates the post injection amount according to the (existing processing) rotation speed, executes the post injection with the calculated post injection amount, and ends the processing.

● [Manual playback process when the driver operates the accelerator (Fig. 3)]
FIG. 3 is a diagram illustrating the relationship between the regeneration process (with the accelerator operation of the driver) and the PM accumulation amount of the filter. FIG. 10 is a diagram showing the relationship between the engine speed and the regeneration process. In FIG. 3, each state when the driver operates the accelerator is shown by a thick solid line. Further, in FIG. 10, the straight line shown by the solid line indicates the case where the filter PM deposit amount is the manual regeneration upper limit deposit amount, and the straight line shown by the dotted line shows that the filter PM deposit amount is smaller than the manual regeneration upper limit deposit amount. Shows the case.

In the upper figure of FIG. 10, the vertical axis shows the reproduction time [t] which is the time from the start to the end of the manual reproduction, and the horizontal axis shows the rotation speed [rpm] of the internal combustion engine. Further, in the figure below, the vertical axis indicates the post injection amount [g], and the horizontal axis indicates the rotation speed [rpm] of the internal combustion engine.

When the driver operates the accelerator to increase the engine speed, the frequency of post-injection also increases up to the post-injection limit start rotation speed (post-injection amount non-restricted region), and the PM incinerator amount increases. As a result, as shown in the upper figure of FIG. 10, the regeneration processing time becomes shorter as the engine speed increases in the post-injection amount non-restricted region. However, when the engine speed exceeds the post injection limit start speed (post injection limit region), the post injection amount is reduced as the speed increases, as shown in the figure below, so the regeneration processing time is long. Become.

The maximum manual rotation speed is the upper limit rotation speed at which the reproduction time becomes the target reproduction time (Tmax). Therefore, when the regeneration process is started from the manual regeneration upper limit deposit amount, the relationship between the regeneration time and the rotation speed becomes a straight line as shown by the solid line in the above figure. In addition, if the regeneration process is started from the filter PM deposition amount smaller than the manual regeneration upper limit deposition amount, the regeneration time becomes shorter than the target regeneration time if the post injection amount is the same, so the relationship between the regeneration time and the rotation speed is It becomes a straight line as shown by the dotted line.
Therefore, when the filter PM accumulation amount is smaller than the manual regeneration upper limit accumulation amount due to the regeneration process, the upper limit rotation speed can be increased to the manual regeneration upper limit rotation speed.
● [Effect of this application]

According to the present invention, in the manual regeneration process by the driver, the regeneration process can be completed within the target reproduction time.

The control device for an internal combustion engine of the present invention is not limited to the configuration, structure, etc. described in the present embodiment, and various changes, additions, and deletions can be made without changing the gist of the present invention.

As shown in FIG. 10, the regeneration processing time is minimized when the engine speed is the post-injection limit start speed. Therefore, in order to minimize the regeneration processing time, the lower limit rotation speed for manual regeneration may be set to the post injection limit start rotation speed in the manual regeneration processing.

10 Internal combustion engine 11 Intake passage 12 Exhaust passage (exhaust path)
14A, 14B, 14C, 14D injector 15 Warning lamp 33 Accelerator opening detection device 34 Rotation detection device 36A, 36B, 36C Exhaust temperature detection device 35 Differential pressure detection device 40 Storage means 41 Exhaust gas purification device 42 Oxidation catalyst 43 DPF (particles) Particulate matter removal filter)
50 Control device 52 Idling speed increase means 54 Post injection execution means 56 Upper limit rotation limit change means 58 Upper limit rotation limit change means 60 Accumulation amount estimation means 62 Residual amount estimation means SW Manual regeneration switch

Claims (4)

A control device for an internal combustion engine in an internal combustion engine system having a filter for collecting particulate matter and an oxidation catalyst arranged on the upstream side of the filter in the exhaust path of the internal combustion engine.
The control device is
The operating state of the internal combustion engine is detected, and the main injection for injecting the amount of fuel corresponding to the detected operating state into the cylinder of the internal combustion engine is performed to control the internal combustion engine and the preset maximum rotation speed. Control the internal combustion engine so that it is less than or equal to the number.
The control device has
The maximum rotation speed, which is the upper limit rotation speed of the internal combustion engine, or the maximum injection amount, which is the upper limit injection amount of the main injection corresponding to the maximum rotation speed, is set.
The particulate matter remaining in the filter after starting manual regeneration to regenerate the filter by burning and incinerating the particulate matter accumulated in the filter by increasing the idling speed and the exhaust temperature. The maximum manual regeneration speed or the maximum manual regeneration injection amount is set based on the target regeneration time, which is the target time until the substance becomes less than or equal to the regeneration end amount.
The control device is
When the manual reproduction instruction is input from the driver and the manual reproduction is started, the idling rotation speed is increased to the manual reproduction lower limit rotation speed set based on the target reproduction time. Ascending means and
When the manual regeneration is started, the post injection is performed by injecting fuel into the cylinder for raising the exhaust temperature in the oxidation catalyst and burning and incinerating the particulate matter accumulated in the filter. Post-injection execution means that injects after the main injection,
When the manual regeneration is started, the upper limit rotation speed of the internal combustion engine is changed to the manual regeneration maximum rotation speed set lower than the maximum rotation speed, or the upper limit of the main injection into the cylinder. An upper limit rotation limiting means for changing the injection amount to the manual regeneration maximum injection amount set lower than the maximum injection amount, and
Have,
Internal combustion engine control device. The control device for an internal combustion engine according to claim 1.
The injection amount of the post injection performed at the time of the manual regeneration is
The injection amount is set according to the rotation speed of the internal combustion engine, and when the rotation speed of the internal combustion engine exceeds the preset post injection limit start rotation speed, the rotation speed of the internal combustion engine increases. It is set to reduce the weight accordingly,
The maximum number of rotations for manual regeneration or the maximum injection amount for manual regeneration is
It is set based on the injection amount of the post injection and the target regeneration time.
Internal combustion engine control device. The control device for an internal combustion engine according to claim 2.
The maximum number of rotations for manual reproduction is
The rotation speed is set to be equal to or higher than the post injection limit start rotation speed and less than the maximum rotation speed.
or,
The maximum manual regeneration injection amount is
The injection amount is set to be equal to or more than the post-limit start injection amount, which is the injection amount corresponding to the post-injection limit start rotation speed, and less than the maximum injection amount.
Internal combustion engine control device. The control device for an internal combustion engine according to claim 2 or 3.
The control device is
A deposit amount estimation means for estimating the amount of particulate matter deposited in the filter, at least when the manual regeneration is not performed.
A means for estimating the residual amount, which estimates the residual amount of the particulate matter in the filter, which has been reduced by combustion incineration when the manual regeneration is performed.
An upper limit rotation limit changing means for changing the maximum manual regeneration speed or the maximum manual regeneration injection amount based on the elapsed time from the start of the manual regeneration, the remaining amount, and the target regeneration time. ,
Have,
Internal combustion engine control device.

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