CONTROL APPARATUS FOR INTERNAL COMBUSTION ENGINE
A control apparatus for an internal combustion engine in the present invention includes a DPF installed in an exhaust passage and a DOC installed in the exhaust passage on the upstream side of the DPF. The control apparatus changes an engine control parameter so as to facilitate NO2-based regeneration when it is determined that an operating state in which the NO2-based regeneration speed is higher than a predetermined threshold value is established during operation of the internal combustion engine.
Latest Toyota Patents:
- VEHICLE COMMUNICATION USING LIGHT PROJECTIONS
- BASE STATION, SYSTEM AND INFORMATION PROCESSING METHOD
- FACILITATING A CONTENT-SHARING SESSION
- GEOFENCE-TRIGGERED CONTENT DELIVERY FOR ELECTRIC VEHICLES AT CHARGING STATIONS
- SYSTEMS AND METHODS FOR ADJUSTING PRESENTATION OF MEDIA CONTENT IN A VEHICULAR ENVIRONMENT
The present invention relates to a control apparatus for an internal combustion engine, and more particular to a control apparatus for an internal combustion engine that is suitable for controlling the internal combustion engine which includes, in an exhaust passage, a particulate filter for trapping particulate matter.
BACKGROUND ARTSo far, for example, Patent Document 1 discloses a diesel engine which actively performs a method (hereinafter, referred to as “NO2-based regeneration) that uses the following oxidation reaction ((2C+2NO2→CO2+2NO) and/or (C+NO2→CO+NO)) using nitrogen dioxide (NO2) to oxidizes and removes, using recirculated NOx, particulate matter (soot) trapped by a diesel particulate filter (DPF).
Including the above described document, the applicant is aware of the following documents as related art of the present invention.
Meanwhile, as a method for oxidizing and removing particulate matter accumulated on a particulate filter, there is known a method (hereinafter, referred to as “O2-based regeneration”) that uses the following oxidation reaction ((C+O2→CO2) and/or (2C+O2→2CO)) to oxidize and remove, using oxygen (O2), particulate matter trapped by the particulate filter, besides the NO2-based regeneration disclosed in Patent Document 1.
In order to efficiently perform the NO2-based regeneration during operation of an internal combustion engine, it is required, as compared to the time of the normal combustion, to increase the amount of NO2 supplied to a particulate filter, and to increase the temperature of the particulate filter albeit to a lower extent compared to the time of the O2-based regeneration. The NO2-based regeneration, however, requires a longer time to regenerate the particulate filter as compared to the O2-based regeneration. It is therefore conceivable that when the NO2-based regeneration is actively performed without sufficient consideration with respect to the operating state at the time of performance of the NO2-based regeneration, the NO2-based regeneration may be performed over a long period of time. As a result, this comes down to problems, such as the deterioration of exhaust emission performance due to an increase in NOx emission and the deterioration of fuel efficiency due to execution of, for example, an additional fuel injection to increase the temperature of the particulate filter.
In addition, due to increased regulation of exhaust gas in recent years, it is expected that from now on, reduction of exhaust emission will be required in broader operating regions than ever before. Because of this, it may be required to achieve a decrease in NOx emission by implementing, for example, enhancement of EGR (Exhaust Gas Recirculation) control in broader operating regions than ever before. As a result, it is anticipated that passive execution of the NO2-based regeneration can not be expected under a situation in which during, for example, high speed traveling, the execution of the NO2-based regeneration has been able to be expected without special consideration in the past. If such situation actually occurs, the frequency of execution of forcible O2-based regeneration increases. This leads to problems such as the deterioration of fuel efficiency and the dilution of oil.
CITATION LIST Patent Documents
- Patent Document 1: Japanese National Publication of International Patent Application No. 2011-511898
- Patent Document 2: International Publication No. WO 02/066813
- Patent Document 3: Japanese National Publication of International Patent Application No. 2011-511897
The present invention has been made to solve the problem as described above, and has its object to provide a control apparatus for an internal combustion engine which can ensure the opportunity in which the NO2-based regeneration is efficiently performed during operation while suppressing an increase in the amount of NOx emission and the deterioration of fuel efficiency as much as possible.
The present invention is a control apparatus for an internal combustion engine that includes: a particulate filter; NO2 production means; NO2-based regeneration speed estimation means; operating state determination means; and control parameter change means.
The particulate filter is installed in an exhaust passage of the internal combustion engine and traps particulate filter. NO2 production means produces NO2 in exhaust gas supplied to the particulate filter. NO2-based regeneration speed estimation means estimates the speed of regeneration of the particulate filter using NO2 (hereinafter, referred to as an “NO2-based regeneration speed”) during operation of the internal combustion engine. Operating state determination means determines whether or not an operating state in which the NO2-based regeneration speed is higher than a predetermined threshold value is established during operation of the internal combustion engine. Control parameter change means changes an engine control parameter so that when the operation state in which the NO2-based regeneration speed is higher than the threshold value is determined to be established by the operation state determination means, at least one of the amount of NO2 supplied to the particulate filter and the temperature of the particulate filter is increased.
According to the present invention, by determining whether or not the operation state in which the NO2-based regeneration speed is higher than the threshold value is established during operation of the internal combustion engine, the engine control parameter can be changed so as to facilitate the NO2-based regeneration with selection of an operating state in which sufficient execution of NO2-based regeneration can be expected. Therefore, the period of performing the aforementioned change in the engine control parameter for facilitating the NO2-based regeneration can be prevented from becoming too long. This can ensure the opportunity in which the NO2-based regeneration is efficiently performed during the operation while suppressing an increase in the amount of NOx emission and the deterioration of fuel efficiency as much as possible.
In addition, the present invention may further include first control parameter change prohibition means for, even when the operation state in which the NO2-based regeneration speed is higher than the threshold value is established, prohibiting a change in the engine control parameter by the control parameter change means in a case in which an outside air temperature is lower than or equal to a predetermined value and/or an engine cooling water temperature is lower than or equal to a predetermined value.
This can ensure the opportunity in which the NO2-based regeneration is efficiently performed during the operation while preventing a lack of performance of a heater of a vehicle due to facilitation of the NO2-based regeneration at the time of low-temperature or preventing an occurrence of combustion deterioration of the internal combustion engine.
Moreover, the present invention may further include second control parameter change prohibition means for, even when the operation state in which the NO2-based regeneration speed is higher than the threshold value is established, prohibiting a change in the engine control parameter by the control parameter change means in a case in which torque control is performed so that a torque of the internal combustion engine is maintained.
This can ensure the opportunity in which the NO2-based regeneration is efficiently performed during the operation while preventing a torque shock from occurring due to facilitation of the NO2-based regeneration during execution of the torque control.
Moreover, the present invention may further include third control parameter change prohibition means for, even when the operation state in which the NO2-based regeneration speed is higher than the threshold value is established, prohibiting a change in the engine control parameter by the control parameter change means in a case in which a vehicle on which the internal combustion engine is mounted is traveling in an urban area.
This can ensure the opportunity in which the NO2-based regeneration is efficiently performed during the operation while preventing an increase in the amount of NOx emission due to facilitation of the NO2-based regeneration when the traveling in an urban area is done.
Moreover, the present invention may further include parameter change suspend means for suspending a change in the engine control parameter by the control parameter change means when the operation state in which the NO2-based regeneration speed is higher than the threshold value has stopped being established during a period in which the change in the engine control parameter is being performed by the control parameter change means.
This allows the change of the engine control parameter for facilitating the NO2-based regeneration to be performed only when an operating state in which sufficient execution of NO2-based regeneration can be expected is more surely selected.
Furthermore, the operating state determination means in the present invention may determine that the operating state in which the NO2-based regeneration speed is higher than the threshold value has been established when the temperature of the particulate filter is higher than a predetermined threshold value and the amount of accumulation of particulate matter in the particulate filter is larger than a predetermined threshold value and the amount of NO2 flown into the particulate filter is larger than a predetermined threshold value.
This can favorably determine whether or not the operation state in which the NO2-based regeneration speed is higher than the threshold value is established during the operation of the internal combustion engine.
A fuel injection valve 12 that directly injects fuel into the cylinder is installed in each cylinder of the internal combustion engine 10. The fuel injection valve 12 of each cylinder is connected to a shared common-rail (not illustrated in the drawings) to which a high pressure fuel which is pressurized by a supply pump (not illustrated in the drawings) is supplied. From this common-rail, the fuel is supplied to the fuel injection valve 12 of each cylinder. Each cylinder is in communication with an intake passage 14 and an exhaust passage 16.
An air cleaner 18 is provided in the vicinity of the inlet of the intake passage 14 of the internal combustion engine 10. An air flow meter 20 for detecting the amount of intake air is installed near the downstream of the air cleaner 18 in the intake passage 14. The air suctioned through the air cleaner 18 is compressed by a compressor 22a of a turbo-supercharger 22. The turbo-supercharger 22 includes a turbine 22b which is operated by exhaust energy of exhaust gas, and a compressor 22a which is integrally coupled to the turbine 22b is driven to rotate by the exhaust energy of the exhaust gas input to the turbine 22b. An intake throttle valve 24 is installed at a section on the downstream side of the compressor 22a in the intake passage 14.
The turbine 22b of the turbo-supercharger 22 is installed at some point in the exhaust passage 16. In the exhaust passage 16 on the downstream side of the turbine 22b, a diesel oxidation catalyst (DOC) 26 and a diesel particulate filter (DPF) 28 are installed in series in the order from the upstream side of exhaust gas to purify the exhaust gas. The DOC 26 has functions to not only oxidize and remove hydrocarbon (HC) and carbon monoxide (CO) but also to oxidize a part of nitrogen monoxide (NO) that is contained in the supplied exhaust gas to convert it into nitrogen dioxide (NO2), under a condition in which oxygen (O2) is present. The DPF 28 has a function to trap particulate matter (PM) that is composed of soot and the like and that is contained in the exhaust gas. The PM (specially, soot) trapped by the DPF 28 is oxidized and removed by execution of a regeneration process described later.
Moreover, a temperature sensor 30 for detecting the temperature of the exhaust gas that is flown into the DOC 26 (DOC inlet gas temperature) is installed in the exhaust passage 16 on the upstream side of the DOC 26, and a temperature sensor 32 for detecting the temperature of the exhaust gas that is flown into the DPF 28 (DPF inlet gas temperature) is installed in the exhaust passage 16 on the upstream side of the DPF 28.
Moreover, the system shown in
The system shown in
A crank angle sensor 46 for detecting a crank angle and an engine speed is installed in the vicinity of a crankshaft 44. In addition, A water temperature sensor 48 for detecting the temperature of the engine cooling water is installed in the internal combustion engine 10.
Furthermore, the system of the present embodiment includes an ECU (Electronic Control Unit) 50. There are electrically connected to the ECU 50, various sensors for detecting the operating state of the internal combustion engine 10, such as the air flow meter 20, the temperature sensors 30 and 32, the crank angle sensor 46, the water temperature sensor 48 and the like that are described above. In addition, there are electrically connected to the ECU 50, a vehicle speed sensor 52 for detecting the speed of the vehicle (not illustrated in the drawings) on which the internal combustion engine 10 is mounted, a shift position sensor 54 for detecting a shift position of a transmission (not illustrated in the drawings) that is combined with the internal combustion engine 10, an accelerator position sensor 56 for detecting the depression amount (accelerator position) of an accelerator pedal of the vehicle, and an outside air temperature sensor 58 for detecting the outside air temperature. Further, there are connected to the ECU 50, various actuators for controlling the operation of the internal combustion engine 10, such as the fuel injection valve 12, the intake throttle valve 24, the HPL-EGR valve 36, the LPL-EGR valve 42 and the like that are described above. The ECU 50 controls the operating state of the internal combustion engine 10 by actuating each actuator on the basis of the output of each sensor and predetermined programs.
As methods of forcibly regenerating the aforementioned DPF 28 by oxidizing and removing the PM (soot) trapped by the DPF 28, there are a method that is forcibly performed using O2 (hereinafter, referred to as “O2-based regeneration”) and a method using NO2 (hereinafter, referred to as “NO2-based regeneration”).
More specifically, according to the O2-based regeneration, when the accumulation amount of soot (PM) to the DPF 28 has reached a predetermined threshold value during operation, the soot (PM) is oxidized and removed using the following oxidation reaction ((C+O2→CO2) and/or (2C+O2→2CO)) by increasing the exhaust gas temperature by use of, for example, executing an after-injection after a main injection to forcibly increase the temperature (floor temperature) of the DPF 28 so as to be higher than or equal to a predetermined regeneration target temperature (for example, 600 degrees Celsius). NO contained in the exhaust gas discharged from the internal combustion engine 10 is oxidized when passing through the DOC 26, and NO2 is produced. According to the NO2-based regeneration, soot (PM) is oxidized and removed using the following oxidization reaction of soot ((C+2NO2→CO2+2NO) and/or (C+NO2→CO+NO)) by increasing the amount of NO2 supplied to the DPF 28 by use of adjustment of an engine control parameter (fuel injection parameter (such as fuel injection timing or pilot injection amount) or the amount of EGR gas) for increasing NOx (NO) discharged from the cylinders, and by increasing the temperature (floor temperature) of the DPF 28 so as to be higher than or equal to a predetermined temperature (about 300 to 400 degrees Celsius) albeit to a relatively lower extent compared to the time of the O2-based regeneration.
In order to efficiently perform the NO2-based regeneration during operation of the internal combustion engine 10, as already described, it is required, as compared to the time of the normal combustion, to increase the amount of NO2 supplied to the DPF 28, and to increase the temperature of the DPF 28 albeit to a lower extent compared to the time of the O2-based regeneration. However, the NO2-based regeneration requires a longer time to regenerate the DPF 28 as compared to the O2-based regeneration. It is therefore conceivable that when the NO2-based regeneration is actively performed without sufficient consideration with respect to the operating state at the time of performance of the NO2-based regeneration, the NO2-based regeneration may be performed over a long period of time. As a result, this comes down to problems, such as the deterioration of exhaust emission performance due to an increase in NOx emission and the deterioration of fuel efficiency due to execution of, for example, an additional fuel injection to increase the temperature of the DPF 28.
In addition, due to increased regulation of exhaust gas in recent years, it is expected that from now on, reduction of exhaust emission will be required in broader operating regions than ever before. Because of this, it may be required to achieve a decrease in NOx emission by implementing, for example, enhancement of EGR (Exhaust Gas Recirculation) control using HPL or LPL in broader operating regions than ever before. As a result, it is anticipated that passive execution of the NO2-based regeneration can not be expected under a situation in which during, for example, high speed traveling, the execution of the NO2-based regeneration has been able to be expected without special consideration in the past. If such situation actually occurs, the frequency of execution of forcible O2-based regeneration increases. This leads to problems such as the deterioration of fuel efficiency and the dilution of oil.
Accordingly, the present embodiment uses an NO2-based regeneration speed model described later with reference to
One example of the predetermined engine operation conditions subject to prohibition of NO2-based regeneration is the time of low-temperature when the outside air temperature and/or the engine cooling water temperature is lower than or equal to a predetermined value. Further, another example of the engine operation conditions is the time of execution of torque control to maintain the torque of the internal combustion engine 10 (for example, the time of idling operation or the time of cruise control at which the torque of the internal combustion engine 10 is made constant to maintain the vehicle speed). Furthermore, the time of traveling in an urban area can be taken as another example of the engine operation conditions. That is to say, according to the present embodiment, when one of the operation conditions is established, the execution of the NO2-based regeneration mode for facilitating the NO2-based regeneration is prohibited even if the NO2-based regeneration speed is larger than the aforementioned threshold value during operation of the internal combustion engine 10, that is, even if the engine 10 is in an operating state in which the NO2-based regeneration can be sufficiently executed.
In the routine shown in
The NO2-based regeneration speed model shown in
As the DPF floor temperature rises, the NO2-based regeneration speed increases. Accordingly, in the NO2-based regeneration speed model, as shown in
Moreover, as the amount of soot accumulation in the DPF 28 increases, the NO2-based regeneration speed increases. Accordingly, in the NO2-based regeneration speed model, as shown in
Furthermore, according to the NO2-based regeneration speed model, as shown in
Further, according to the NO2-based regeneration speed model shown in
In the routine shown in
If the determination of step 102 becomes affirmatives established following the affirmative determination of step 100, the NO2-based regeneration mode is executed (step 104). The NO2-based regeneration mode, as already described, is an operation mode for facilitating the NO2-based regeneration (for increasing the NO2-based regeneration speed) compared to the time of the normal combustion that uses an identical operating region (more specifically, an operation mode for increasing the amount of NO2 supplied to the DPF 28 and for raising the floor temperature of the DPF 28).
The NO2-based regeneration mode can be implemented by, for example, changing the engine control parameters compared to that at the time of the normal combustion as follows. More specifically, when transitioning to the NO2-based regeneration mode, for example, a control map for a predetermined engine control parameter (EGR gas amount or fuel injection parameter) is switched from a control map used at the time of the normal combustion mode. In detail, by switching such control map, the amount of EGR gas using the LPL-EGR and/or HPL-EGR is decreased in order to increase the amount of NOx discharged from the cylinders (as one example, the introduction of the EGR gas using the LPL-EGR and/or HPL-EGR is stopped). In addition, in order to raise the floor temperature of the DPF 28 to a predetermined value (300-400 degrees Celsius) or more that is required at the time of NO2-based regeneration and to increase the amount of NOx discharged from the cylinders, the control map is switched to optimize the fuel injection parameter so that a crank angle position at which combustion is generated is moved to the retard side compared to that at the time of the normal combustion. Specifically, for example, the fuel injection timing is retarded with respect to the value at the time of the normal combustion, and the amount of pilot injection is increased to suppress the deterioration of combustion in association therewith. Alternatively, in order to raise the exhaust gas temperature, the control map is switched so that an after-injection is executed.
Further, in the NO2-based regeneration mode, feedback control for at least one of the DPF floor temperature, the DOC floor temperature and the NOx emission amount may be executed in order to maintain high the NO2-based regeneration speed. Such feedback control can, for example, be executed by adjusting the exhaust gas temperature with a change in the amount of the after-injection and the fuel injection timing (further, by adjusting the NOx emission amount). Moreover, if a combustion model is installed in an ECU of an internal combustion engine and the operation of the internal combustion engine can be controlled on the basis of the combustion model, the following method may be used. More specifically, in terms of how the NO2-based regeneration speed can be raised while suppressing the deterioration of combustion as much as possible, the combination of the engine control parameters that is capable of obtaining the optimum exhaust gas temperature (for example, the EGR gas amount and the fuel injection parameter) may be fixed using the aforementioned combustion model. Alternatively, if such a sophisticated combustion model is not installed, the relation of each change amount of the fuel efficiency, the NOx emission amount and the exhaust gas temperature with respect to a change in the engine control parameters (that is, sensitivity coefficients of the engine control parameters with respect to the fuel efficiency and the like) may be installed in advance as a map or a curve for every engine control parameter, in each operating region of the internal combustion engine. Based on such relation of the map or the like, a control value of each engine control parameter at the time of the NO2-based regeneration mode may be fixed.
On the other hand, in the routine shown in
According to the routine shown in
In the future, in order to address exhaust emission regulations for a vehicle traveling state (off-cycle state) that is out of statutory mode conditions in the exhaust emission regulations (for example, the NEDC mode conditions in Europe), it is anticipated that the operating region in which EGR control is executed for the purpose of reduction in the NOx emission amount will be extended to a region on the higher load side. As a result of this, at the time of high-speed traveling or the like in which an advantageous effect of the NO2-based regeneration has been expected to be obtained due to a relatively high exhaust gas temperature in the past, the effect of the NO2-based regeneration may not be sufficiently obtained due to a decrease in the amount of NOx discharged from the cylinders. In addition to that, smoke becomes easy to be discharged by introducing the EGR gas at the time of high-load operation, and the accumulation of soot in the DPF 28 therefore becomes rather easy to progress at the time of high-speed traveling as shown by the broken line in
In contrast, in order to facilitate the effect of the NO2-based regeneration in an operating state such as a high-load operation of the internal combustion engine, in which the NO2-based regeneration speed is high, the present embodiment changes the engine control parameters within a range in which the deterioration of NOx emission and fuel efficiency is prevented as much as possible, on the condition that an operation condition that requires the trade-off is not met. This efficiently produces the effect of the NO2-based regeneration at the time of high-speed traveling (the time of high-load operation of the internal combustion engine 10) in which high NO2-based regeneration speed can be originally expected to be achieved, as shown by the solid line in
In addition, according to the aforementioned routine, even if the NO2-based regeneration speed estimated by the NO2-based regeneration speed model is higher than the aforementioned threshold value, transitioning to the NO2-based regeneration mode is prohibited when any of the aforementioned predetermined engine operation conditions subject to prohibition of NO2-based regeneration is met. Such control that prohibits the transitioning to the NO2-based regeneration mode at the time of low-temperature produces the following advantageous effects. More specifically, if the amount of EGR gas is decreased or the introduction of EGR is ceased as a result of the transitioning to the NO2-based regeneration mode at the time of low-temperature, heat becomes hard to be obtained when the engine cooling water flows through the EGR cooler 40. As a result of this, there is a concern that the performance of a heater of the vehicle may be insufficient. Moreover, if the retard of the fuel injection timing is executed as a result of the transitioning to the NO2-based regeneration mode at the time of low-temperature, there is a concern that the combustion may be deteriorated at the time of low-temperature. In contrast, the lack of heater performance and the deterioration of fuel efficiency can be prevented at the time of low-temperature by prohibiting the transitioning to the NO2-based regeneration mode even when the operating state in which sufficient NO2-based regeneration is expected has come.
Further, the transitioning to the NO2-based regeneration mode is prohibited at the time of execution of the torque control that maintains engine torque at a constant value, such as the time of idling operation and the time of cruise control, and thereby a torque shock can be prevented from occurring due to a change in the engine control parameters for facilitating the NO2-based regeneration. Moreover, the transitioning to the NO2-based regeneration mode is prohibited at the time of traveling in an urban area, and thereby the amount of NOx emission can be prevented from increasing due to facilitation of the NO2-based regeneration when the traveling in an urban area is done. Furthermore, according to the control of the present embodiment, if the aforementioned prohibition condition concerning the NO2-based regeneration is met, the implementation of the prohibition condition has priority over ensuring the opportunity of the NO2-based regeneration. That is to say, ensuring the opportunity of the NO2-based regeneration by the control of the present embodiment can be permitted consistently under a situation in which there is no concern about any adverse effects.
Furthermore, according to the aforementioned routine, if the NO2-based regeneration speed decreases to or below the aforementioned threshold value after the NO2-based regeneration mode is started, or if any of the engine operation conditions subject to prohibition of NO2-based regeneration is met, the execution of the NO2-based regeneration mode is not maintained until the amount of soot accumulation decreases to a target value, but the execution is immediately suspended. Such control more definitely ensures the execution of the NO2-based regeneration that is limited at efficient operating states and the execution of the NO2-based regeneration that is limited under engine operation conditions in which there is no concern about any adverse effects. Therefore, an increase in the amount of NOx emission or the deterioration of fuel efficiency due to maintaining the NO2-based regeneration under insufficient situations can be more surely prevented. In addition, adverse effects such as the lack of performance of the heater can be more surely prevented from occurring due to maintaining the NO2-based regeneration under the aforementioned engine operation conditions subject to prohibition.
It is noted that in the first embodiment, which has been described above, the DPF 28 corresponds to the “particulate filter” according to the present invention; and the DOC 26 corresponds to the “NO2 production means” according to the present invention. In addition, the ECU 50 calculates the NO2-based regeneration speed using the NO2-based regeneration speed model shown in
Moreover, in the above described first embodiment, the ECU 50 executes the aforementioned processing of step 106 when the aforementioned determination of step 102 is not established, whereby the “first control parameter change prohibition means” according to the present invention is realized.
Moreover, in the above described first embodiment, the ECU 50 executes the aforementioned processing of step 106 when the aforementioned determination of step 102 is not established, whereby the “second control parameter change prohibition means” according to the present invention is realized.
Moreover, in the above described first embodiment, the ECU 50 executes the aforementioned processing of step 106 when the aforementioned determination of step 102 is not established, whereby the “third control parameter change prohibition means” according to the present invention is realized.
Furthermore, in the above described first embodiment, the ECU 50 executes the aforementioned processing of step 106 when the aforementioned determination of step 100 or 102 is negative, whereby the “parameter change suspend means” according to the present invention is realized.
DESCRIPTION OF SYMBOLS10 internal combustion engine
12 fuel injection valve
14 intake passage
16 exhaust passage
20 air flow meter
22 turbo-supercharger
26 diesel oxidation catalyst (DOC)
28 diesel particulate filter (DPF)
30, 32 temperature sensor
34 high-pressure exhaust gas recirculation passage (HPL)
36 HPL-EGR valve
38 low-pressure exhaust gas recirculation passage (LPL)
40 EGR cooler
42 LPL-EGR valve
44 crankshaft
46 crank angle sensor
48 water temperature sensor
50 ECU (Electronic Control Unit)
52 vehicle speed sensor
54 shift position sensor
56 accelerator position sensor
58 outside air temperature sensor
Claims
1. A control apparatus for an internal combustion engine, comprising:
- a particulate filter that is installed in an exhaust passage of the internal combustion engine and traps particulate filter; and
- a controller that is programmed to:
- produce NO2 in exhaust gas supplied to the particulate filter;
- estimate an NO2-based regeneration speed that is a speed of regeneration of the particulate filter using NO2, during operation of the internal combustion engine;
- determine whether or not an operating state in which the NO2-based regeneration speed is higher than a predetermined threshold value is established during operation of the internal combustion engine; and
- change an engine control parameter so that when determining that the operation state in which the NO2-based regeneration speed is higher than the threshold value is established, an amount of NO2 supplied to the particulate filter and a temperature of the particulate filter are increased,
- wherein the controller determines that the operating state in which the NO2-based regeneration speed is higher than the threshold value has been established when a present temperature of the particulate filter is higher than a predetermined temperature threshold value and a present amount of accumulation of particulate matter in the particulate filter is larger than a predetermined accumulation amount threshold value and a present amount of NO2 flown into the particulate filter is larger than a predetermined NO2 amount threshold value.
2. The control apparatus for the internal combustion engine according to claim 1,
- wherein even when the operation state in which the NO2-based regeneration speed is higher than the threshold value is established, the controller prohibits a change in the engine control parameter in a case in which an outside air temperature is lower than or equal to a predetermined value and/or an engine cooling water temperature is lower than or equal to a predetermined value.
3. The control apparatus for the internal combustion engine according to claim 1,
- wherein even when the operation state in which the NO2-based regeneration speed is higher than the threshold value is established, the controller prohibits a change in the engine control parameter in a case in which torque control is performed so that a torque of the internal combustion engine is maintained.
4. The control apparatus for the internal combustion engine according to claim 1,
- wherein even when the operation state in which the NO2-based regeneration speed is higher than the threshold value is established, the controller prohibits a change in the engine control parameter in a case in which a vehicle on which the internal combustion engine is mounted is traveling in an urban area.
5. The control apparatus for the internal combustion engine according to claim 1,
- wherein the controller suspends a change in the engine control parameter when the operation state in which the NO2-based regeneration speed is higher than the threshold value has stopped being established during a period in which the change in the engine control parameter is being performed.
6. The control apparatus for the internal combustion engine according to claim 3,
- wherein a case in which cruise control to control the torque of the internal combustion engine is performed so that a speed of a vehicle is maintained corresponds to the case in which the torque control is performed so that the torque of the internal combustion engine is maintained.
7. A control apparatus for an internal combustion engine, comprising:
- a particulate filter that is installed in an exhaust passage of the internal combustion engine and traps particulate filter;
- NO2 production means for producing NO2 in exhaust gas supplied to the particulate filter;
- NO2-based regeneration speed estimation means for estimating an NO2-based regeneration speed that is a speed of regeneration of the particulate filter using NO2, during operation of the internal combustion engine;
- operating state determination means for determining whether or not an operating state in which the NO2-based regeneration speed is higher than a predetermined threshold value is established during operation of the internal combustion engine; and
- control parameter change means for changing an engine control parameter so that when the operation state in which the NO2-based regeneration speed is higher than the threshold value is determined to be established by the operation state determination means, an amount of NO2 supplied to the particulate filter and a temperature of the particulate filter are increased,
- wherein the operating state determination means determines that the operating state in which the NO2-based regeneration speed is higher than the threshold value has been established when a present temperature of the particulate filter is higher than a predetermined temperature threshold value and a present amount of accumulation of particulate matter in the particulate filter is larger than a predetermined accumulation amount threshold value and a present amount of NO2 flown into the particulate filter is larger than a predetermined NO2 amount threshold value.
Type: Application
Filed: Nov 25, 2011
Publication Date: Aug 7, 2014
Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA (Toyota-shi)
Inventor: Akira Shirai (Susono-shi)
Application Number: 14/347,497
International Classification: F01N 3/023 (20060101);