JP2008297969A - Exhaust emission control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine compatibly materializing suppression of oil dilution quantity and inhibition of deterioration of fuel economy by post injection. <P>SOLUTION: In a DPF (Diesel Particulate Filter) collecting particulate matters such as soot and un-burned component from exhaust gas of a diesel engine, oil dilution quantity which is quantity of fuel diluting engine oil is calculated from operation conditions and regeneration time of the DPF. Suppression of oil dilution quantity and inhibition of deterioration of fuel economy due to post injection can be compatibly materialized by relaxing increase of oil dilution quantity by using regeneration method reducing oil dilution quantity further when oil dilution quantity exceeds a predetermined value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust gas purification apparatus for an internal combustion engine in which a diesel particulate filter (hereinafter also referred to as DPF) for exhaust gas purification is mounted on an exhaust pipe.

  As a conventional technique, when the amount of particulate matter (hereinafter also referred to as PM), which is particulate matter such as soot and unburned material, contained in the exhaust of the engine exceeds a predetermined value, In order to effectively burn the PM of the engine, a technique called post injection in which additional fuel is injected in the expansion stroke after the main injection of the engine and the additional fuel is directly fed to the DPF is disclosed (Patent Document 1, Patent Document 2). ).

Japanese Patent Application No. 8-42326

Japanese Patent Application No. 2005-307746

  However, since the post injection is performed in the expansion stroke, the injected fuel is difficult to evaporate and easily adheres to the wall surface of the cylinder. There is a problem that the fuel adhering to the cylinder wall descends from the gap between the piston ring and the cylinder and dilutes the engine oil.

  Furthermore, if post-injection is repeated over a long period of time, and the amount of fuel that dilutes oil (hereinafter also referred to as oil dilution amount) becomes excessive, poor lubrication of the piston will occur, or evaporated fuel will enter the intake side and engine rotation will increase There was a possibility of problems such as.

  An object of the present invention is to provide an exhaust emission control device for an internal combustion engine that achieves both oil dilution suppression and post-injection fuel consumption deterioration suppression.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above problems, an exhaust purification device for an internal combustion engine in the present invention is an exhaust purification device for an internal combustion engine provided with a diesel particulate filter that collects particulate matter contained in the exhaust of the engine, Measured by a control unit that controls the operation of the exhaust gas purification device of the internal combustion engine, a particulate matter accumulation amount measurement unit that measures the amount of particulate matter accumulated in the diesel particulate filter, and a particulate matter accumulation amount measurement unit Particulate matter accumulation amount determination means for determining whether or not the accumulation amount of particulate matter exceeds a first predetermined value, and an oil dilution amount that is the amount of fuel diluted in engine oil Oil dilution relation data measurement means for measuring the oil dilution relation data necessary for the operation, and oil dilution relation data measured by the oil dilution relation data measurement means. Is provided with oil dilution relation data determination means for determining whether or not the second predetermined value is exceeded, and regeneration means for burning the particulate matter and regenerating the diesel particulate filter. 1 regeneration means and two regeneration means having a lower oil dilution amount than the first regeneration means and a second regeneration means having a high fuel consumption rate, and the control unit uses the particulate matter accumulation amount determination means, It is determined that particulate matter exceeding the first predetermined value is deposited on the diesel particulate filter, and the oil dilution relationship data measured by the oil dilution relationship data determination means is determined to be lower than the second predetermined value. In this case, the first regeneration means is selected from the two regeneration means, and particulate matter exceeding the first predetermined value is detected by the particulate matter accumulation amount judgment means. A selection means for selecting the second regeneration means from the two regeneration means when it is determined that the oil is accumulated on the particulate filter and the measured oil dilution relation data is determined to be higher than the second predetermined value; It is characterized by providing.

  Due to this feature, the exhaust gas purification apparatus for an internal combustion engine according to the present invention has a "first regeneration means with a large amount of oil dilution but a small deterioration in fuel consumption" according to the amount of oil dilution in the current engine. The “second regeneration means” can be selected and used, and the deterioration of fuel consumption can be suppressed while the oil dilution amount is set to a predetermined value or less. That is, there is an effect that it is possible to achieve both suppression of oil dilution during DPF regeneration and suppression of deterioration in fuel consumption.

  Further, the first regeneration means may perform post injection for performing fuel injection in an expansion stroke, and the second regeneration means may perform the post injection at a more advanced injection timing during the expansion stroke. .

  As a result, there are provided two regeneration means, “a first regeneration means with a large amount of oil dilution but a small deterioration in fuel consumption” and “a second regeneration means with a small amount of oil dilution but a large deterioration in fuel consumption” without providing a special external device. be able to. That is, there is an effect that two kinds of reproducing means can be provided without extra cost.

  Further, the post-injection can be characterized by being injected in a plurality of times during the expansion stroke.

  With this feature, it is possible to reduce the post injection amount per injection even with the same post injection amount. As a result, the amount of fuel adhering to the cylinder can be reduced and the amount of oil dilution can be reduced.

  The oil dilution relationship data measuring means is a vehicle speed and a travel distance during execution of either the first regeneration means or the second regeneration means, or the first regeneration means or the second regeneration means. It may be measured from the vehicle speed and the running time during the execution of either of the above.

  Due to this feature, when the vehicle speed is low and the exhaust temperature is low, the DPF regeneration time becomes long, and the oil dilution amount increases. From this relationship, there is an effect that the oil dilution amount can be obtained.

  In addition, the oil dilution related data measuring means can be measured from the duration during which either the first regeneration means or the second regeneration means is being executed.

  Generally, when the DPF regeneration time becomes longer, the oil dilution amount increases. With the above feature, the exhaust gas purification apparatus for an internal combustion engine according to the present invention has an effect that the oil dilution amount can be derived from the DPF regeneration time.

  Further, the oil dilution amount measuring means can be derived from a difference between the oil dilution amount and the oil evaporation amount that is the amount of fuel evaporated from the oil.

  With this feature, there is an effect that the oil dilution amount can be more accurately derived from the difference between the oil dilution amount and the oil evaporation amount.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a system diagram of an exhaust emission control device for an internal combustion engine 1 according to an embodiment of the present invention. First, there is a diesel engine 2 which is a prime mover. Further, as sensors for knowing the state of the diesel engine 2, an air flow meter 3 that measures the flow rate of air on the intake side of the diesel engine 2, an engine rotation sensor 4 that measures the rotation of the diesel engine 2, and the opening degree of the accelerator of the driver An accelerator opening sensor 5 is provided for measuring. The diesel engine 2 is provided with an injector provided with a fuel injection valve for injecting fuel, and is electrically connected to an ECU (engine control unit) 10 which is a control unit. The opening degree and timing of the fuel injection valve for the injector to inject fuel are managed by the ECU 10. The air flow meter 3, the engine rotation sensor 4, and the accelerator opening sensor 5 are also electrically connected to the ECU 10 that is a control unit, and transmit measured values to the ECU 10. Based on this measured value, the ECU 10 grasps and manages the state of the engine.

  Next, an exhaust temperature sensor 6 for measuring the exhaust temperature as a sensor for obtaining information on exhaust from the engine, and an oxygen concentration sensor 7 for measuring the oxygen concentration of exhaust between the diesel engine 2 and the DPF 9 for removing PM. , There is a differential pressure sensor 8 (particulate matter accumulation amount measuring unit) that measures the pressure difference between the exhaust gas before and after the DPF 9. The exhaust temperature sensor 6, the oxygen concentration sensor 7, and the differential pressure sensor 8 are also connected to the ECU 10, which is a control unit, similarly to the engine rotation sensor 4 and the accelerator opening sensor 5, and transmit measured values to the ECU 10. The transmitted measurement value is used to grasp the state of the engine. Further, the differential pressure measured by the differential pressure sensor 8 is used for examining the PM accumulation amount of the DPF 9.

  FIG. 2 is a diagram illustrating a configuration example of the ECU 10 according to the embodiment of the present invention. The ECU 10 includes a CPU 20 that controls each component, a ROM 21 that stores a control program, various data, and the like, a RAM 22 that is a work area for operations performed by the CPU 20, and an EEPROM 23 that is a non-volatile memory and stores various settings. Each exchanges data via the bus 50. Electrical connection to the outside of each sensor or the like is realized through the bus 50 and the I / O 51.

  The ROM 21 posts a PM deposition amount calculation program 31 (particulate matter deposition amount determination means) for calculating the amount of PM deposited on the DPF 9 from the differential pressure measured by the differential pressure sensor 8, and the temperature during regeneration of the DPF 9. DPF temperature control program 32 controlled by injection, driving state measurement program 34 (oil dilution relation data measuring means) for measuring vehicle speed, travel distance and travel time as data for calculating the oil dilution amount, engine coolant temperature, An oil evaporation amount calculation program 35 (oil dilution relation data measuring means) that is the amount of fuel evaporated from the oil from the oil dilution amount, and an oil dilution amount calculation program 36 that calculates the oil dilution amount from the engine speed and the engine output torque (Oil dilution related data measuring means) and DPF regeneration time measurement for measuring the regeneration time of DPF 9 Constructed out program 37 (the oil dilution related data measurement means). The CPU 20 performs various processes by expanding the contents of the ROM 21 onto the RAM 22. Also, various processing values necessary for processing are expanded from the EEPROM 23 to the RAM 22 to perform various processing, and when the settings are changed, the settings are saved by writing the values in the EEPROM 23.

  Hereinafter, with reference to the flowchart, the post-injection control during the regeneration of the DPF 9 in the present invention will be described. The regeneration process of the DPF 9 refers to a process for burning and removing PM in the DPF when the amount of accumulated PM collected by the DPF 9 exceeds a predetermined value. In this example, post injection is performed after main injection, PM accumulated in the DPF 9 is removed by combustion or the like by combustion of the fuel, and the DPF 9 is regenerated.

  FIG. 3 is a flowchart showing the regeneration process of the DPF 9 according to the first embodiment of the present invention. First, the ECU 10 determines whether or not the amount of PM deposited on the DPF 9 exceeds a first predetermined value that requires regeneration of the DPF 9 (S100). The determination method is performed using a known technique. As a known technique, for example, there is a method in which the pressure difference between the inlet and the outlet of the DPF 9 is measured by the differential pressure sensor 7 to estimate the PM deposition amount. First, when the PM accumulation amount is large, the differential pressure measured by the differential pressure sensor increases. When this differential pressure exceeds a predetermined value, it is determined that the PM accumulation amount on the DPF 9 exceeds a first predetermined value that requires regeneration of the DPF 9. On the other hand, in S100, when the PM accumulation amount falls below the first predetermined value (S100: NO), the ECU 10 next determines whether the PM accumulation amount exceeds the first predetermined value that requires regeneration of the DPF 9. The wait state is entered until a determination is made.

  When the PM accumulation amount exceeds the first predetermined value that requires regeneration of the DPF 9 (S100: YES), the ECU 10 starts regeneration of the DPF 9 (S110). By performing post-injection during regeneration of the DPF 9, unburned fuel is sent to the DPF 9 together with the exhaust gas, and the PM in the DPF 9 is combusted by the oxidation heat of the oxidation catalyst carried on the DPF 9, thereby accumulating on the DPF 9. The PM you are doing decreases. Accumulation of a large amount of PM leads to a decrease in engine output because exhaust emissions deteriorate, so regeneration is indispensable for the DPF 9. Note that the temperature at which PM starts burning is about 550 ° C.

  Post-injection at the time of regeneration means that fuel is injected into the cylinder in a state where the piston descends after passing through the top dead center, and also means that fuel adheres to the cylinder wall. As described in paragraphs 0005 and 0006, the fuel adhering to the cylinder wall may cause oil dilution and may cause a phenomenon such as poor lubrication of the piston and a phenomenon in which the evaporated fuel flows to the intake side and the engine speed increases.

  In order to avoid the above phenomenon, the ECU 10 subsequently determines whether or not the oil dilution amount, which is the amount of fuel diluted in engine oil, exceeds a predetermined amount (S120). Since it is difficult to directly measure the oil dilution amount, whether or not the oil dilution amount exceeds a predetermined amount is determined according to the driving situation. For example, when the low speed operation is continued for a period of a predetermined time or more, the low temperature exhaust is continued. This leads to a large amount of unburned fuel adhering to the cylinder wall, and oil dilution proceeds. Therefore, when low-speed driving | running is continued over the period more than predetermined time, it determines with the oil dilution amount exceeding the predetermined amount (S120: NO). For example, in this embodiment, the condition is that the operation at a vehicle speed of 20 km / h or less continues for 60 minutes or more. Of course, the condition of whether or not the oil dilution amount exceeds a predetermined amount is not limited to this condition.

  Moreover, it is good also as a case where low speed driving | running is continued over a predetermined distance or more as judgment conditions whether the oil dilution amount exceeds the predetermined amount. In the present embodiment, for example, the condition is that the operation at a vehicle speed of 20 km / h or less continues for 20 km or more. Of course, the condition of whether or not the oil dilution amount exceeds a predetermined amount is not limited to this condition.

  When the ECU 10 determines that the low speed operation is not continued, that is, the oil dilution amount does not exceed the predetermined amount (S120: NO), the ECU 10 subsequently determines whether the oil dilution amount exceeds the predetermined amount. As another determination condition for determining whether or not the reproduction duration has exceeded a second predetermined value, it is determined (S130). Since the post-injection is continuously performed during regeneration of the DPF 9 and the oil dilution amount continues to increase, this determination should be used as a reference for determining whether or not the oil dilution amount has reached a predetermined value. Can do. If the regeneration time is continued for a long time, the oil dilution amount may be significantly increased. Therefore, the regeneration means is switched so that the oil dilution amount does not increase.

  If the regeneration continuation time does not exceed the second predetermined value in S130 (S130: NO), the ECU 10 determines that the oil dilution amount does not exceed the predetermined amount, and burns the PM in the DPF 9 In order to proceed efficiently, the first reproduction means is implemented (S140).

  FIG. 4A shows the relationship between the crank angle and the opening of the fuel injection valve in the first regeneration means. The parts where the fuel injection valve is open are, in order from the left, air and fuel are mixed before ignition, pilot injection 61 that suppresses engine operation noise, main injection 62 for obtaining power, and PM accumulated in the DPF 9 after explosion The post-injection A63 and the post-injection B64, which are performed to send unburned fuel to the DPF 9 as the fuel for burning the fuel, are shown. If a large amount of post-injection is performed at a time with the piston descending past the top dead center, unburned fuel that exceeds a predetermined amount will adhere to the cylinder wall, causing an increase in the amount of oil dilution. . However, by dividing the post-injection, it becomes possible to reduce the post-injection amount per injection and increase the cylinder volume for the fuel. This reduces unburned fuel adhering to the cylinder wall and reduces the amount of oil dilution. TDC (Top Dead Center) represents the top dead center of the piston. In this example, it can be seen from FIG. 4A that the main injection starts immediately after the top dead center.

  In FIG. 4A, the post injection A and the post injection B are executed at a timing considerably delayed from the main injection 62. By delaying the injection timing, the amount of fuel that reaches the DPF 9 without being burned increases, so that the PM in the DPF 9 can be burned efficiently with a relatively small post-injection amount. On the other hand, since the fuel is injected while the temperature in the cylinder is relatively low, the amount of unburned fuel that reaches the cylinder wall increases, causing an increase in the amount of oil dilution.

  Further, the increase in unburned fuel reaching the DPF 9 means that the injection amount or the number of injections until the fixed amount of fuel reaches the DPF 9 is reduced, and the deterioration of the fuel consumption is reduced. The

  Subsequently, the ECU 10 determines whether or not the amount of accumulated PM has been sufficiently reduced by the regeneration of the DPF 9 (S160). The determination is performed using a known technique as in S100. When the amount of accumulated PM is sufficiently reduced, the ECU 10 ends the regeneration of the DPF 9 (S160: YES). If the amount of accumulated PM has not decreased, the ECU 10 returns to S120 and regenerates the DPF 9 (S160: NO).

  On the other hand, when it is determined in S120 that the oil dilution amount exceeds the predetermined amount (S120: YES), the ECU 10 performs the second regeneration means in order to mitigate the increase in the oil dilution amount (S120: YES). S150).

  FIG. 4B shows the relationship between the crank angle of the second regeneration means and the opening of the fuel injection valve. Compared to FIG. 4A, it can be seen that the post injection timing is earlier. By advancing the timing of the post injection, the post injection is performed while the pressure in the cylinder is high as compared with the first regeneration means, so that the fuel reaching the cylinder wall is reduced, and the oil dilution amount is reduced. The increase is mitigated.

  However, since the fuel is injected while the injection timing is early and the temperature in the cylinder at the time of post-injection is high, part of the post-injected fuel is combusted. Although this combustion is engine output, it is combustion at a time away from the top dead center, so the combustion efficiency is lowered and the fuel consumption is deteriorated. This reduced combustion efficiency is discharged as heat energy from the engine to the exhaust, but some heat escapes from the exhaust pipe to the outside air before reaching the DPF 9. Therefore, the proportion of the fuel that is effectively used to raise the temperature of the DPF 9 in the post-injected fuel is smaller than that in the first regeneration means, which causes the fuel consumption to deteriorate. FIG. 5A is a diagram comparing the temperatures in the cylinders of the first regeneration unit and the second regeneration unit, FIG. 5B is a diagram comparing the oil dilution amounts, and FIG. 5C is a diagram comparing fuel consumption. As can be seen from this figure, the temperature and fuel consumption in the cylinder are greater in the second regeneration means than in the first regeneration means, and the oil dilution amount is greater in the first regeneration means than in the second regeneration means. Many.

  The ECU 10 that has performed the regeneration moves to S160, and the ECU 10 determines whether or not the PM accumulation amount has decreased sufficiently. When the ECU 10 determines that the PM accumulation amount has sufficiently decreased (S160: YES), the ECU 10 ends the regeneration of the DPF 9. If the ECU 10 determines that the PM accumulation amount has not decreased sufficiently (S160: NO), the ECU 10 returns to S120 and selects the regeneration means from the oil dilution amount.

  On the other hand, when the regeneration continuation time exceeds the second predetermined value in S130 (S130: YES), the ECU 10 determines that the oil dilution amount has increased, and the second operation is performed to mitigate the increase in the oil dilution amount. The reproducing means is implemented (S150).

  The above is the first embodiment. Next, a second embodiment of the present invention will be described.

  FIG. 6 is a flowchart showing the regeneration process of the DPF 9 according to the second embodiment of the present invention. First, the ECU 10 calculates the amount of oil evaporation (S200). The amount of oil evaporation varies depending on the warm-up state of the engine (which can be determined by the engine coolant temperature, etc.) and the current oil dilution amount. The relationship between the three has been experimentally obtained in advance and stored in the ECU 10. An increase in the engine coolant temperature means that the temperature inside the engine rises, so that the fuel in the oil also easily evaporates, leading to an increase in the amount of oil evaporation. Further, when the oil dilution amount increases, the fuel evaporated in the oil also increases, so that the oil evaporation amount also increases. FIG. 7A shows an increase in the amount of oil evaporation due to the engine coolant temperature and the amount of oil dilution. In FIG. 7A, the oil evaporation amount line having the same oil evaporation amount is drawn on the line, and the oil evaporation amount increases by increasing at least one of the engine cooling water temperature and the oil dilution amount.

  Subsequently, the ECU 10 determines whether or not the amount of PM deposited on the DPF 9 exceeds a first predetermined value that requires the regeneration of the DPF 9 (S210). This process is the same as in the first embodiment. When the PM accumulation amount exceeds the first predetermined value that requires regeneration of the DPF 9 (S210: YES), the ECU 10 executes post injection and regenerates the DPF 9. Start (S220). Further, when the PM accumulation amount falls below the first predetermined value (S210: NO), the ECU 10 next determines whether or not the PM accumulation amount exceeds a first predetermined value that requires regeneration of the DPF 9. Enter the waiting state until The amount of PM deposited is measured by a known technique, an example of which is described in paragraph 0025.

  Subsequently, the ECU 10 starts regeneration of the DPF 9 (S220). This process is the same as in the first embodiment and is described in paragraph 0026.

  Subsequently, the ECU 10 calculates the oil dilution amount (S230). Oil dilution is related to engine speed and output torque. Further, it is greatly influenced by the post injection amount. FIG. 7B shows an increase in the amount of oil dilution with engine output torque and engine speed. An oil dilution amount line having equal oil dilution amounts is drawn on the line, and the oil dilution amount decreases as at least one of the engine output torque and the engine speed increases. When the engine speed and the engine output torque are low, the exhaust temperature is low. Therefore, for regeneration of the DPF 9, it is necessary to send a large amount of fuel to the DPF 9 by post injection. This is because a large amount of fuel adheres to the cylinder, causing an increase in the amount of oil dilution.

  Then, ECU10 calculates | requires the quantity of the fuel currently diluting engine oil from the oil dilution amount and the oil evaporation amount. Since the oil dilution amount represents the amount of fuel diluted with engine oil before evaporation, the amount of fuel evaporated after dilution (oil evaporation amount) is also included. By subtracting the amount of fuel evaporated after dilution from the oil dilution amount, the amount of fuel currently diluting the engine oil can be obtained. The ECU 10 determines whether or not the amount of fuel diluted in the engine oil thus obtained exceeds a third predetermined value (S240). By so doing, the amount of fuel in which the engine oil is diluted can be determined more accurately than in the first embodiment, and the ECU 10 can more accurately select the regeneration means. FIG. 8 shows a transition of the amount of fuel diluted with engine oil (difference between the oil dilution amount and the oil evaporation amount) according to the travel distance (travel time). During regeneration, post-injection is performed, so the amount of fuel diluted in engine oil increases. In addition, since post-injection is not performed during non-regeneration, the fuel diluted with engine oil only evaporates, and the amount of fuel diluted with engine oil decreases. When the amount of fuel diluting the engine oil exceeds the threshold A, the ECU 10 switches the regeneration means from the first regeneration means to the second regeneration means, and increases the amount of fuel diluting the engine oil. Relaxes.

  If the amount of fuel diluted in engine oil obtained in paragraph 0046 does not exceed the third predetermined value (S240: NO), the ECU 10 prioritizes the suppression of fuel consumption deterioration and efficiently burns PM in the DPF 9 In order to proceed well, the first reproduction means is implemented (S250). The first reproducing means is the same as that of the first embodiment, and is described in paragraphs 0032 and 0033.

  Subsequently, the ECU 10 determines whether or not the PM accumulation amount has sufficiently decreased due to the regeneration of the DPF 9 (S270). The determination is performed using a known technique (using a method similar to that described in paragraph 0025) as in the first embodiment. When the amount of accumulated PM is sufficiently reduced, the ECU 10 ends the regeneration of the DPF 9 (S270: YES). If the amount of accumulated PM has not decreased, the ECU 10 returns to S230 and regenerates the DPF 9 (S170: NO).

  On the other hand, if the amount of fuel diluted in the engine oil obtained in paragraph 0046 exceeds the third predetermined value (S240: YES), the ECU 10 determines that the oil dilution amount has increased, and the oil dilution In order to mitigate the increase in the amount, the second regeneration means is implemented (S260). The second reproducing means is the same as that in the first embodiment, and is described in paragraphs 0037 and 0038.

  The particulate matter accumulation amount determination means in the present invention is S100 in FIG. 3 and S210 in FIG. 6, and the oil dilution relation data measurement means is S120 and S130 in FIG. 3 and S200 and S220 in FIG.

  The present invention is not limited to the above-described embodiment, and it is obvious that changes can be made within the scope of the technical idea. For example, a configuration may be adopted in which the oil dilution amount is obtained directly from the viscosity of the engine oil using an oil level sensor, a viscosity sensor, or a component equivalent thereto.

1 is a system diagram of an exhaust emission control device for an internal combustion engine according to an embodiment of the present invention. The figure which showed the structural example of ECU10 which concerns on embodiment of this invention. The flowchart which showed the reproduction | regeneration processing of DPF9 which concerns on the 1st Embodiment of this invention. The figure showing the relationship between the crank angle of the 1st reproduction | regeneration means which concerns on the 1st Embodiment of this invention, and the opening degree of a fuel injection valve. The figure showing the relationship between the crank angle of the 2nd reproduction | regeneration means which concerns on the 1st Embodiment of this invention, and the opening degree of a fuel injection valve. The figure which compared the temperature in the cylinder of the 1st reproduction | regeneration means which concerns on the 1st Embodiment of this invention, and the 2nd reproduction | regeneration means. The figure which compared the oil dilution amount of the 1st reproduction | regeneration means and 2nd reproduction | regeneration means which concern on the 1st Embodiment of this invention. The figure which compared the fuel consumption deterioration of the 1st reproduction | regeneration means and 2nd reproduction | regeneration means which concern on the 1st Embodiment of this invention. The flowchart which showed the reproduction | regeneration processing of DPF9 which concerns on the 2nd Embodiment of this invention. The figure which showed increase / decrease in the amount of oil evaporation by engine cooling water temperature and oil dilution amount. The figure which showed increase / decrease in the oil dilution amount by an engine output torque and an engine speed. The figure showing the relationship between what subtracted the amount of oil evaporation from the amount of oil dilution, and travel time (travel distance).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Diesel engine 3 Air flow meter 4 Engine rotation sensor 5 Accelerator opening sensor 6 Exhaust temperature sensor 7 Oxygen concentration sensor 8 Differential pressure sensor 9 DPF (diesel particulate filter)
10 ECU (Engine Control Unit)
20 CPU
21 ROM
22 RAM
23 EEPROM
31 PM accumulation amount measurement program 32 DPF temperature control program 34 Operating state measurement program 35 Oil evaporation amount calculation program 36 Oil dilution amount calculation program 37 DPF regeneration time measurement program 50 Bus 51 I / O
61 Pilot injection 62 Main injection 63 Post injection A
64 Post injection B

Claims (6)

An exhaust purification device for an internal combustion engine having a diesel particulate filter that collects particulate matter contained in the exhaust of the engine,
A control unit for controlling the operation of the exhaust emission control device of the internal combustion engine;
A particulate matter deposition amount measuring unit for measuring the amount of particulate matter deposited in the diesel particulate filter;
Particulate matter deposition amount determination means for determining whether or not the particulate matter deposition amount measured by the particulate matter deposition amount measurement unit exceeds a first predetermined value;
Oil dilution relationship data measuring means for measuring oil dilution relationship data necessary for deriving an oil dilution amount that is the amount of fuel diluted in engine oil;
Oil dilution relation data determination means for determining whether the oil dilution relation data measured by the oil dilution relation data measurement means exceeds a second predetermined value;
Regenerating means for combusting the particulate matter and regenerating the diesel particulate filter,
The regeneration means is two regeneration means: a first regeneration means and a second regeneration means having a lower fuel dilution rate and a higher fuel consumption rate than the first regeneration means,
The control unit determines that the particulate matter exceeding the first predetermined value is deposited on the diesel particulate filter by the particulate matter accumulation amount judgment unit, and the oil dilution relation data judgment unit When it is determined that the measured oil dilution relation data is lower than the second predetermined value, the first regeneration means is selected from the two regeneration means,
Further, it is determined by the particulate matter accumulation amount judgment means that particulate matter exceeding the first predetermined value is deposited on the diesel particulate filter, and the measured oil dilution relation data is the first data. An exhaust emission control device for an internal combustion engine, comprising: a selection unit that selects the second regeneration unit from the two regeneration units when it is determined that the value is higher than a predetermined value of 2. The first regeneration means performs post injection for performing fuel injection in an expansion stroke,
2. The exhaust gas purification apparatus for an internal combustion engine according to claim 1, wherein the second regeneration unit performs the post-injection at a more advanced injection timing during the expansion stroke.   The exhaust purification device for an internal combustion engine according to claim 1 or 2, wherein the post-injection is performed in a plurality of times during the expansion stroke.   The oil dilution relationship data measuring means is configured to use the oil dilution relationship data as a vehicle speed and a travel distance during execution of either the first regeneration means or the second regeneration means, or the first regeneration. 4. The exhaust gas purification apparatus for an internal combustion engine according to claim 1, wherein the exhaust gas purification device is measured from a vehicle speed and a running time during execution of either the first regeneration unit or the second regeneration unit.   4. The oil dilution-related data measuring means is measured from a duration time during which either the first regeneration means or the second regeneration means is being executed. An exhaust gas purification apparatus for an internal combustion engine as described.   4. The exhaust gas of an internal combustion engine according to claim 1, wherein the oil dilution relation data measuring means is derived from a difference between the oil dilution amount and an oil evaporation amount which is an amount of fuel evaporated from the oil. Purification equipment.

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