JP4457693B2 - Engine exhaust purification system - Google Patents

Description

    The present invention relates to an exhaust emission control device for an engine provided with a filter for collecting particulates (floating particulate matter such as black smoke) in exhaust gas in an exhaust passage.

    When the filter is provided in the exhaust passage of the engine, it is necessary to regenerate the filter by burning the particulates when the amount of particulates collected by the filter exceeds a predetermined amount. Regarding this regeneration, there is known a forced regeneration means for raising the temperature of the filter and burning the particulates deposited on the filter while the vehicle is running when the amount of collected particulates exceeds a predetermined amount. (See Patent Document 1). That is, in Patent Document 1, an electric heater carrying an oxidation catalyst is provided upstream of the filter, and when the filter is forcedly regenerated when the exhaust gas temperature is low, the electric heater is energized and the engine expands. In the stroke, a small amount of fuel is injected into the cylinder to supply unburned fuel to the catalyst of the electric heater, and the temperature of the filter is raised using the combustion reaction heat of the fuel in the catalyst to burn the fine particles. It is described.

Also known is that a warning lamp is turned on when the collected amount of particulate matter in the filter exceeds a predetermined amount to prompt the driver to stop the vehicle and perform manual regeneration of the filter. (See Patent Document 2). In this manual regeneration, when the vehicle is stopped and the manual regeneration switch is turned on while the engine is idling, the exhaust gas temperature is increased by turning on the idle up lever and increasing the engine speed, and then immediately before the filter. The electric heater is energized to increase the temperature of the filter.
JP-A-8-42325 JP-A-3-202612

    However, in both the forced regeneration while the vehicle is running and the manual regeneration while the vehicle is stopped, it is necessary to supply the fuel and energize the electric heater to raise the temperature of the filter. A large amount of energy is consumed.

    Accordingly, an object of the present invention is to improve an engine exhaust gas purification apparatus provided with the above-described forced regeneration means or manual regeneration means from the viewpoint of energy saving.

    According to the present invention, for such a problem, even if the amount of collected particulates of the filter becomes a predetermined amount or more, the vehicle then enters a high-speed traveling state, the exhaust gas temperature increases, and the filter burns the particulates. We focused on the fact that the temperature could rise to a possible temperature. That is, in this case, even if the filter regeneration means is not operated, the fine particles of the filter are burned and naturally regenerated. Therefore, if this natural regeneration can be actively used, energy can be saved. . Hereinafter, the present invention will be specifically described.

The invention according to claim 1 is a filter provided in an exhaust passage of an engine of a vehicle for collecting particulates in exhaust gas;
Fine particle amount detection means for detecting a parameter value related to the amount of fine particles collected by the filter;
While the vehicle is running, the filter is configured so that the particulates collected by the filter are combusted when the particulate amount of the filter exceeds a predetermined amount based on the detection value of the particulate amount detection means. An exhaust emission control device for an engine comprising a forced regeneration means for forcibly regenerating the filter by raising the temperature of the filter,
Means for detecting the current location of the host vehicle, map information storage means, and means for inputting the travel destination of the host vehicle, and based on the map information, the travel route to the destination is determined by inputting the destination. A navigation system for setting and providing vehicle speed related information of the travel route;
When the amount of fine particles in the filter exceeds a predetermined amount, based on the vehicle speed related information on the travel route, the forced regeneration means does not work while the host vehicle travels to a predetermined point on the travel route. Traveling environment determination means for determining whether or not the temperature of the filter rises and shifts to a traveling environment in which particulates of the filter naturally burn;
When it is determined by the traveling environment determining means that the vehicle travels to the natural combustion traveling environment while traveling to the predetermined point, the forced regeneration means continues until the host vehicle has passed the traveling environment. A forced regeneration suppression means for suppressing execution ,
The traveling environment determining means includes particulate amount data in which the particulate amount discharged from the engine per unit traveling distance is set in correspondence with the road type, and the road type of the traveling route obtained from the map information and the particulate amount Based on the data, the amount of particulates collected by the filter when traveling on the travel route is estimated, and a point at which the total particulate collection amount of the filter reaches a second predetermined amount larger than the predetermined amount is determined. The predetermined point is used .

    In the engine exhaust gas purification apparatus, even if the amount of particulates collected by the filter exceeds a predetermined amount, the natural combustion travels while the host vehicle travels to a predetermined point based on vehicle speed related information by the navigation system. When it is determined to shift to the environment, the forced regeneration means does not work and the regeneration of the filter is left to natural combustion. As described above, according to the present invention, since the opportunity of natural regeneration of the filter is positively utilized, the number of forced regenerations can be reduced without causing clogging of the filter, thereby saving energy.

    Then, the amount of particulates collected by the filter when traveling along the travel route is estimated, and the amount of particulates collected by the filter does not exceed the second predetermined amount. This can prevent clogging. The amount of engine particulate emission in accordance with the road type may be determined, for example, according to the size relationship of “highway <suburban road <urban road”.

The invention according to claim 2 is a filter that is provided in an exhaust passage of an engine of a vehicle and collects particulates in exhaust gas;
Fine particle amount detection means for detecting a parameter value related to the amount of fine particles collected by the filter;
Warning means for issuing a warning to a vehicle occupant when the amount of the particulates exceeds a predetermined amount based on the detection value of the particulate amount detection means;
A manual regeneration switch for manually starting the regeneration of the filter;
When both the condition that the vehicle is in a predetermined stop state and the condition that the manual regeneration switch is turned on are satisfied, the temperature of the filter is adjusted so that the particulates collected in the filter are burned. An exhaust purification device for an engine, comprising manual regeneration means for raising and performing manual regeneration of the filter,
Means for detecting the current location of the host vehicle, map information storage means, and means for inputting the travel destination of the host vehicle, and based on the map information, the travel route to the destination is determined by inputting the destination. A navigation system for setting and providing vehicle speed related information of the travel route;
When the amount of fine particles in the filter exceeds a predetermined amount, the manual regeneration means must be operated while the host vehicle travels to a predetermined point on the travel route based on the vehicle speed related information on the travel route. Traveling environment determination means for determining whether or not the temperature of the filter rises and the transition to a traveling environment in which the particulates of the filter naturally burn,
The warning means operates until the own vehicle has passed the running environment when the running environment judging means determines that the own vehicle shifts to the spontaneous combustion running environment while the own vehicle is running to the predetermined point. Manual regeneration suppression means for prohibiting ,
The traveling environment determining means includes particulate amount data in which the particulate amount discharged from the engine per unit traveling distance is set in correspondence with the road type, and the road type of the traveling route obtained from the map information and the particulate amount Based on the data, the amount of particulates collected by the filter when traveling on the travel route is estimated, and a point at which the total particulate collection amount of the filter reaches a second predetermined amount larger than the predetermined amount is determined. The predetermined point is used .

    Even in the case of this invention, even if the amount of particulates collected by the filter exceeds a predetermined amount, the vehicle shifts to a natural combustion traveling environment while the host vehicle travels to a predetermined point based on vehicle speed related information by the navigation system. If it is determined, the operation of the warning means is prohibited, and the regeneration of the filter is left to natural combustion. That is, since the warning means does not operate, the driver of the vehicle does not stop and actively perform manual regeneration of the filter, and energy saving can be achieved without causing clogging of the filter. In addition, warnings for manual regeneration are not frequently issued, and it is less likely that the vehicle occupant is forced to perform manual regeneration, thereby reducing the burden on the occupant.

    Then, the amount of particulates collected by the filter when traveling along the travel route is estimated, and the amount of particulates collected by the filter does not exceed the second predetermined amount. This can prevent clogging. The amount of engine particulate emission in accordance with the road type may be determined, for example, according to the size relationship of “highway <suburban road <urban road”.

The invention according to claim 3 is the invention according to claim 1 or claim 2,
The navigation system includes means for receiving road traffic information, and provides the road type based on the map information and the road traffic information as vehicle speed related information of the travel route.

    Therefore, depending on the road type (for example, highway, urban road, suburban road, or high or low road speed limit) according to the map information, a relatively high vehicle speed is maintained on the travel route to the destination. It is possible to determine whether or not there is a section in which the vehicle can travel, that is, the above-described natural combustion traveling environment. In addition, even if the existence of a natural combustion driving environment is confirmed by map information, if road traffic information related to vehicle speed restrictions such as traffic regulation, traffic jams or accidents in that driving environment is obtained, natural combustion It can be determined that there is no driving environment. In addition, when the road traffic information related to the vehicle speed limit is obtained in the travel section until the transition to the natural combustion travel environment based on the map information, the amount of particulates in the filter is reduced before the transition to the natural combustion travel environment. Since there is a high possibility that the vehicle will increase excessively beyond the predetermined amount, it can be determined that the host vehicle cannot shift to the natural combustion traveling environment while traveling from the current location to the predetermined point.

    As described above, according to the present invention, since the road type based on the map information and the road traffic information are used as the vehicle speed related information of the travel route, the vehicle shifts to a natural combustion travel environment while the host vehicle travels to a predetermined point. Whether or not to do so can be determined with high accuracy.

The invention according to claim 4 is the invention according to claim 3,
The travel environment determination means corrects the particulate matter data so that the particulate matter discharged from the engine per unit travel distance increases when road traffic information that restricts the speed of the host vehicle is obtained. It is characterized by.

    That is, when road traffic information related to vehicle speed restrictions such as traffic regulation, traffic congestion or accident occurrence is obtained, the vehicle speed until the host vehicle transitions to the natural combustion travel environment decreases, The number of times the start is repeated increases, and the amount of fine particles discharged from the engine increases accordingly. In this case, the fine particle amount data is corrected.

The invention according to claim 5 is any one of claims 1 to 4 ,
The means for raising the temperature of the filter injects the fuel into the cylinder in the expansion stroke after the main injection in which the fuel is injected into the cylinder near the top dead center of the electric stroke or the compression stroke of the engine. The fuel is supplied to an oxidation catalyst arranged on the upstream side of the filter, and the filter is heated by the combustion reaction heat of the fuel in the oxidation catalyst.

    That is, in the case of an electric heater, an in-vehicle battery is consumed, so that the amount of power generated by the engine increases to replenish electric power to the battery, and a large amount of fuel is consumed. Even when the filter is heated using an oxidation catalyst, a large amount of fuel is consumed because it is necessary to supply fuel to the oxidation catalyst. Therefore, if the above-described forced regeneration or manual regeneration is frequently performed, the fuel efficiency of the vehicle is deteriorated. However, according to the present invention, the filter is regenerated by actively using the traveling environment of natural combustion. This will improve fuel efficiency.

As described above, according to the present invention, when the amount of particulates in the filter exceeds a predetermined amount, the host vehicle travels to a predetermined point on the travel route based on the vehicle speed related information of the travel route by the navigation system. In the meantime, when shifting to the natural combustion traveling environment, the execution of the filter forced regeneration means is suppressed or the operation of the warning means for manual regeneration of the filter is prohibited until the traveling environment has been passed. It is possible to actively utilize the opportunity for the filter to regenerate naturally and reduce the energy consumption for filter regeneration by reducing the number of forced regeneration or manual regeneration without causing clogging of the filter. it can. In addition, the particulate emission amount of the engine per unit mileage is collected by the filter when traveling along the travel route based on the particulate amount data determined according to the road type and the road type obtained from the map information. Since the predetermined point is a point at which the total amount of collected particulates of the filter reaches a second predetermined amount that is larger than the predetermined amount, the self-vehicle moves to a natural combustion traveling environment. This is advantageous in preventing the amount of fine particles in the filter from becoming excessive and causing clogging.

Further, when the road type and road traffic information based on the map information is used as the vehicle speed related information, it is accurately determined whether or not to shift to a natural combustion travel environment while the host vehicle travels to a predetermined point. It can be determined, without causing clogging of the filter, preferably ing in reducing energy consumption for the filter regeneration.

In addition , when the road traffic information that restricts the vehicle speed of the host vehicle is obtained, the particle amount data is corrected so that the amount of particles discharged from the engine per unit travel distance increases. This is further advantageous in preventing the amount of fine particles in the filter from becoming excessively clogged before the vehicle moves to a natural combustion traveling environment.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Engine configuration>
In the engine exhaust gas purification apparatus shown in FIG. 1, 1 is a multi-cylinder diesel engine of a vehicle (only one cylinder is shown in FIG. 1), 2 is its intake passage, and 3 is its exhaust passage. A deep dish combustion chamber 5 is formed on the top surface of the piston 4 of the engine 1. The cylinder head of the engine 1 is provided with a fuel injection valve 7 so that fuel can be directly injected into the in-cylinder combustion chamber 5.

    In the intake passage 2, the air cleaner 9, the air flow sensor 10, the blower 11 a of the turbocharger 11, the intercooler 12, the intake throttle valve 13, the intake temperature sensor 14, and the intake pressure are sequentially arranged from the upstream side to the downstream side. A sensor 15 is provided. In the exhaust passage 3, a turbine 11 b of the turbocharger 11, an oxidation catalyst 16, and a diesel particulate filter (DPF) 17 that collects particulates in the exhaust gas are disposed in order from the upstream side to the downstream side. ing. Exhaust pressure sensors 18 and 19 are disposed upstream and downstream of the filter 17.

    Further, the upstream side of the exhaust passage 3 with respect to the turbine 11b and the downstream side of the intake passage 2 with respect to the intake pressure sensor 15 are connected by an exhaust gas recirculation passage 21 for returning a part of the exhaust gas to the intake system. . In the middle of the exhaust gas recirculation passage 21, a negative pressure actuator type exhaust gas recirculation amount control valve (EGR valve) 22 and a cooler 23 for cooling the exhaust gas with engine coolant are disposed.

    Fuel in the fuel tank (not shown) is supplied to the fuel injection valve 7 by a fuel supply pipe 28 via a fuel filter 25, a fuel injection pump 26, and a common rail 27 as a pressure accumulating means, and a fuel return pipe 29 supplies the fuel tank. Returned. That is, the high pressure fuel pumped from the fuel pump 26 is stored in the common rail 27, and the fuel stored in the common rail 27 is distributed and supplied to the fuel injection valves 7 of the cylinders of the engine 1.

    31 is a water temperature sensor that detects the engine water temperature, 32 is a crank angle sensor that detects the engine speed, 33 is a sensor that detects the exhaust gas temperature flowing into the oxidation catalyst 16, and 34 is a sensor that detects the exhaust gas temperature flowing into the filter 17. , 35 are sensors for detecting the exhaust gas temperature flowing out from the filter 17.

    Next, a control system for regenerating the filter 17 will be described.

<Embodiment 1>
-Control system configuration-
An ECU (engine control unit) 40 using a microcomputer shown in FIG. 2 is used for forced regeneration in which the particulates are burned to regenerate the filter 17 when the amount of particulates collected by the filter 17 increases. In addition, a navigation system 41 is provided to appropriately suppress the forced regeneration using map information and road traffic information.

    That is, the ECU 40 can shift to a forced regeneration means 42 that regenerates the filter 17 by fuel injection control by the fuel injection valve 7 during traveling of the vehicle, and a traveling environment in which the host vehicle can achieve natural regeneration of the filter 17. A traveling environment determination unit 43 that determines whether or not there is a possibility, and a forced regeneration suppression unit 44 that suppresses the execution of the forced regeneration unit 42 when there is such a possibility. Further, exhaust pressure sensors 18 and 19, a crank angle sensor 45, an accelerator opening sensor 46 for detecting the accelerator opening (depressing amount of the accelerator pedal), and a vehicle speed sensor 47 are provided for forced regeneration of the filter. Yes.

    The exhaust pressure sensors 18 and 19 constitute a fine particle amount detecting means for detecting a parameter value related to the fine particle amount collected by the filter 17. That is, the amount of fine particles accumulated on the filter 17 is detected based on the differential pressure between the exhaust pressures detected by the sensors 18 and 19, and the larger the differential pressure, the larger the accumulated amount is determined. can do. The accelerator opening sensor 46 is used to determine the engine load. The accelerator opening sensor 46 and the crank angle sensor 45 detect the parameter values related to the engine operating state (engine load and engine speed). The operating state detecting means is configured.

    The forced regeneration means 42 determines that the amount of particulates collected by the filter 17 is greater than or equal to a predetermined amount α based on detection signals from the exhaust pressure sensors 18 and 19, and the vehicle is based on the output of the vehicle speed sensor 47. When it is determined that the oxidation catalyst 16 is in an operation state in which the oxidation catalyst 16 is activated (a predetermined vehicle speed (for example, 50 km / h or more)), the filter 17 is forcibly regenerated. That is, the filter 17 is regenerated by executing the sub-injection in which the fuel is injected in the expansion stroke after the main injection in which the fuel is injected near the top dead center of the compression stroke to generate the engine output. Then, the forced regeneration is terminated when the amount of the fine particles becomes equal to or less than the predetermined amount β. Note that α> β.

    The main injection control is performed by setting the main injection amount and the main injection timing with reference to a map that is preset and electronically stored based on the engine speed and the engine load. And correction based on intake air temperature and the like.

    The sub-injection control is also performed by setting the sub-injection amount and sub-injection timing with reference to a map that is preset and electronically stored based on the engine speed and the engine load. By this sub-injection, unburned fuel or partially oxidized fuel is supplied to the oxidation catalyst 16, the exhaust gas temperature flowing into the filter 17 is increased by the catalytic reaction heat in the oxidation catalyst 16, and the temperature of the filter 17 is combusted by fine particles. Raise as you do.

    The sub-injection amount is basically set such that the sub-injection amount increases as the engine load decreases and as the engine speed decreases. This is because the lower the engine load and the lower the engine speed, the lower the exhaust gas temperature due to main injection and the smaller the amount of exhaust gas. The sub-injection timing is such that the engine load is within the range of 50 ° CA to 120 ° CA in the ATDC (after the top dead center of the compression stroke) in order to discharge the injected fuel by being slightly thermally decomposed so as to be easily burned by the oxidation catalyst 16. The higher the engine speed is, the slower the engine speed is set.

    The navigation system 41 calculates a current location and a traveling direction of the vehicle based on a GPS antenna 52 for receiving a transmission radio wave from a GPS (Global Positioning System) artificial satellite and a received signal from the GPS antenna 52. GPS receiver 53, a gyro compass 54 provided on the vehicle for detecting a change in the traveling direction of the host vehicle, a vehicle speed sensor 47 for detecting the traveling speed of the host vehicle, , An operation unit 56 for inputting various commands such as designation of a travel route from the current location to the destination, and a player 57 for reading the map information from a CD-ROM (or DVD) storing map information. A display 58 for displaying a road map and the current location, a GPS receiver 53, a gyro compass 54, a vehicle speed sensor 7. The information from the operation unit 56 and the CD-ROM player 57 is taken in, and the current location, traveling direction, destination, traveling route, etc. of the host vehicle are mainly displayed on the display 58, and the host vehicle travels to the driver. A navigation control unit 51 for providing guidance.

    In the map information stored in the CD-ROM, the road type (by expressway, suburban road, and urban road) is stored for each predetermined section of the road, the altitude of each point on the road, the position of the traffic light, etc. Is remembered.

    The GPS receiver 52 is used for so-called GPS navigation, and measures the current location and traveling direction of the host vehicle based on radio waves from a GPS artificial satellite. On the other hand, the gyrocompass 54 and the vehicle speed sensor 47 are used for so-called autonomous navigation, and detect the relative movement amount of the vehicle and update the current location and the traveling direction sequentially while updating the current location and the traveling direction. This is supplemented when the measurement result by the GPS receiver 53 is not normal, such as when the vehicle cannot receive radio waves from the artificial satellite.

    Further, in this embodiment, a traffic information receiver 60 that acquires the traffic information from a communication network that provides traffic information such as VICS by the beacon receiving antenna 59 is mounted, and receives road traffic information of the own vehicle travel route. This is demodulated and sent to the navigation control unit 51.

    The navigation control unit 51 of the navigation system 41 and the ECU 40 described above are connected so as to be able to communicate with each other, and in response to a request from the ECU 40, road information (map information and road information) mainly on a travel route to the destination of the host vehicle. Traffic information) is transmitted from the navigation control unit 51.

    In the navigation system 41, the GPS antenna 52, the GPS receiver 53, the gyro compass 54, and the vehicle speed sensor 47 constitute a means for detecting the current location of the host vehicle, and the CD-ROM and its player 57 constitute a map information storage means. The operation unit 56 constitutes input means.

    When the amount of particulate matter in the filter 17 exceeds a predetermined amount α, the traveling environment determination unit 43 determines that the host vehicle is traveling to a predetermined point on the traveling route based on road information on the traveling route, particularly information related to the vehicle speed. While traveling, it is determined whether or not the temperature of the filter 17 rises without moving the forced regeneration means 42 to shift to a traveling environment where the particulates collected by the filter 17 naturally burn.

    Specifically, the travel environment determination unit 43 includes fine particle amount data in which the fine particle amount discharged from the engine per unit travel distance is set in correspondence with the road type, and the travel route of the travel route obtained from the map information. Based on the road type and the fine particle amount data, the amount of fine particles collected by the filter 17 when traveling on the travel route is estimated, and the total fine particle collection amount of the filter 17 is larger than the predetermined amount α. 2 A point reaching a predetermined amount is set as the predetermined point.

    That is, X (g / km) is the particulate emission per unit mileage when traveling on a highway, Y (g / km) is the same when traveling on a suburban road, and Z (g / km) is the same on a city road. km) (provided that X <Y <Z), and when the vehicle travels on the travel route from the X, Y, Z values and travel distance, it is added to the predetermined amount and collected by the filter 17. The amount of fine particles will be determined. Therefore, the distance that can be traveled until the total amount of collected particulate matter of the filter 17 reaches the second predetermined amount is obtained from the particulate matter data and the road type of the travel route.

    In this case, the predetermined amount can be set to a level at which an adverse effect such as an increase in back pressure does not occur on the engine, and the second predetermined amount can be set as a guard value for avoiding clogging of the filter 17.

    The fine particle amount data is obtained when road traffic information (traffic regulation, traffic congestion, accident occurrence information) that restricts the vehicle speed of the host vehicle is obtained from the navigation system 41 in the travel section to the predetermined point. The correction is made so that the amount of fine particles discharged from the engine per unit travel distance increases.

    Further, the travel environment determination means 43 is a travel capable of spontaneous combustion of particulates in the filter 17 in a travel section that is classified as a highway in the map information and has no road traffic information that restricts the speed of the host vehicle. Set as environment.

    The forced regeneration suppression unit 44 finishes passing through the travel environment when the travel environment determination unit 43 determines that the vehicle travels to the natural combustion travel environment while traveling to the predetermined point. Until then, execution of the forced regeneration means 42 is suppressed, specifically, execution of forced regeneration is prohibited.

-Control flow-
The travel destination of the host vehicle is input in advance using the operation unit 56 of the navigation system 41, and the travel route is set. Specifically, when the travel destination is input, the control unit 51 moves from the current location to the destination based on the current location obtained from the GPS receiver 53 and the gyrocompass 54 and the map information stored in the CD-ROM player 57. Is calculated and displayed on the display 58 together with the map. When there are a plurality of travel routes, the occupant selects with the operation unit 56.

    As shown in FIG. 3, navigation information is detected in step A1 after the start. Specifically, the map information related to the vehicle speed (the road type of the travel route, the number of traffic lights, etc.) is read from the CD-ROM of the navigation system 41, and the road related to the vehicle speed of the travel route is obtained by the traffic information receiver 40. Import traffic information (traffic regulations, traffic jams, occurrence of accidents).

    In subsequent step A2, the differential pressure P between the exhaust pressures before and after the filter 17 is read by the detection signals of the exhaust pressure sensors 18 and 19, and the particulate accumulation amount M of the filter 17 is calculated based on the differential pressure P in step A3. In the subsequent step A4, it is determined whether or not the fine particle accumulation amount M is greater than or equal to a predetermined amount α. When the particulate accumulation amount M is smaller than the predetermined amount α, the filter 17 is not forcibly regenerated and the process returns (step A5).

    When the particulate accumulation amount M of the filter 17 is greater than or equal to the predetermined amount α, the traveling environment is such that the temperature of the filter 17 rises and the particulates naturally burn while the host vehicle travels to a predetermined point in step A6. It is determined whether or not to shift to. That is, based on the particulate discharge amount X, Y, Z per unit travel distance determined according to the road type of the particulate amount data, and the road type of the travel route obtained from the map information, the total particulates of the filter 17 A point where the collected amount reaches the second predetermined amount (the predetermined point) is obtained. In this case, when road traffic information (traffic regulation, traffic congestion, accident occurrence) that restricts the vehicle speed is obtained, the predetermined point is obtained by correcting the particulate emission amounts X, Y, and Z to be increased. .

    Then, the traveling environment in which the high-speed traveling can be continued from the current position to the predetermined point to raise the filter 17 to a temperature at which the particulates burn, specifically, a high speed extending beyond a predetermined length. Whether or not a road exists is determined from the map information. In this case, even if there is such an expressway, if there is road traffic information (traffic regulation, traffic congestion, accident occurrence) that restricts the vehicle speed in that travel section, such a natural combustion travel environment Is determined not to exist.

    As a result of the above determination, if there is no travel environment for natural combustion between the current location and the predetermined point, the routine proceeds to a forced regeneration execution routine, and if there is such a travel environment, the routine proceeds to a forced regeneration suppression routine.

    FIG. 4 shows a forced regeneration execution routine when there is no traveling environment for natural combustion. In step B1 after the start, the differential pressure P between the exhaust pressures before and after the filter 17 is read by the detection signals of the exhaust pressure sensors 18 and 19, and the particulate accumulation amount M of the filter 17 is calculated in step B2 based on the differential pressure P. . In a subsequent step B3, it is determined whether or not the fine particle accumulation amount M is equal to or less than a predetermined amount β. When the particulate deposition amount M is larger than the predetermined amount β, the process proceeds to step B4, where the forced regeneration of the filter 17 is executed by the forced regeneration means 42, and when the particulate deposition amount M becomes less than the predetermined amount β, the forced regeneration is performed. The routine ends and returns (step B5).

    FIG. 5 shows a forced regeneration suppression routine in the case where there is a traveling environment for natural combustion. In step C1 after the start, navigation information (map information related to vehicle speed and road traffic information related to vehicle speed) is fetched from the navigation system 41. In the subsequent step C2, the differential pressure P between the exhaust pressures before and after the filter 17 is read from the detection signals of the exhaust pressure sensors 18 and 19, and the particulate accumulation amount M of the filter 17 is calculated based on the differential pressure P in step C3. In subsequent step C4, it is determined whether or not the fine particle accumulation amount M is equal to or larger than a second predetermined amount.

    When the particulate accumulation amount M is smaller than the second predetermined amount, the process proceeds to step C5 to determine whether or not the passage through the section where the natural combustion traveling environment exists has been completed. Proceeding to C6, execution of forced regeneration is suppressed, that is, prohibited. On the other hand, when the vehicle has passed the section where the natural combustion travel environment exists, the forced regeneration suppression routine is terminated and the routine returns (step C7). In Step C4, when the particulate accumulation amount M of the filter 17 is equal to or larger than the second predetermined amount, the routine proceeds to a forced regeneration execution routine.

    FIG. 6 is a time chart showing the transition of the particulate accumulation amount of the filter 17 according to the present invention. When the traveling distance of the vehicle V increases and the particulate accumulation amount gradually increases to become a predetermined amount α or more (current location). ), The point (the position ● in the figure) where the host vehicle arrives before the particulate deposition amount reaches the second predetermined amount is obtained based on the particulate emission data and the navigation information. Then, it is determined whether or not the traveling environment in which the particulates of the filter 17 can spontaneously burn is reached before reaching that point.

    When there is such a traveling environment, forced regeneration is suppressed, and therefore the amount of particulate deposition gradually increases. However, since it shifts to a travel environment in which natural combustion is possible before the second predetermined amount is reached, the particulates of the filter 17 start to burn from there, so that the amount of accumulated particulates gradually decreases, and the travel environment in which natural combustion is possible. When the passage is completed, the forced regeneration suppression control ends. In FIG. 6, “warning cancellation” relates to the second embodiment described later.

    As described above, even when the amount of accumulated particulate matter on the filter 17 becomes equal to or larger than the predetermined amount α, the host vehicle may move to a traveling environment where the filter 17 can be naturally regenerated before reaching the second predetermined amount. Since the forced regeneration is suppressed and the opportunity of such natural regeneration is actively used, the number of forced regenerations can be reduced without causing clogging of the filter, thereby saving energy. In addition, since the determination as to whether or not there is a possibility of shifting to the driving environment is performed in consideration of not only the map information but also the road traffic information, the determination becomes highly reliable, and the filter 17 is clogged. It is advantageous to avoid the situation that occurs.

    Further, even when it is determined that the natural regeneration traveling environment is present and forced regeneration is suppressed, it is determined whether or not the actual particulate accumulation amount M of the filter 17 is equal to or greater than the second predetermined amount, 2 When the amount exceeds the predetermined amount, the routine is shifted to the forced regeneration execution routine. As a result, a sudden traffic jam or accident occurs on the travel route, or the vehicle is forced to stop idle. Thus, when the amount of accumulated particulate matter increases unexpectedly, forced regeneration is executed, and clogging of the filter 17 is reliably prevented.

<Embodiment 2>
This embodiment is a case provided with a manual regeneration means for the filter 17.

-Control system configuration-
FIG. 7 shows the configuration of the control system. The difference from the first embodiment is that the ECU 40 has a manual regeneration means 62 and a manual regeneration suppression means 63 instead of the forced regeneration means and the forced regeneration suppression means. For the means 62, in addition to the sensors 18, 19, 45 to 47, a shift range (select lever position) sensor 48 of the automatic transmission, a manual regeneration switch 49 for manually starting regeneration of the filter 17, and an occupant The warning means 64 and the warning lamp 65 for prompting manual regeneration are provided. A warning lamp 65 and a manual regeneration switch 49 are provided on the instrument panel of the vehicle.

    The manual regeneration means 62 satisfies the condition that the vehicle speed is zero and the condition that the select lever is in the P (parking) range or the N (neutral) range based on the outputs from the vehicle speed sensor 47 and the shift range sensor 48. Then, when it is determined that the vehicle is in a stopped state, and when it is determined that the particulate accumulation amount M of the filter 17 is equal to or larger than the predetermined amount α and the manual regeneration switch 49 is turned on, the manual regeneration of the DPF 17 is performed. The manual regeneration is finished when the amount of fine particles in the filter 17 becomes equal to or less than the predetermined amount β. The relationship between the predetermined amounts α and β is α> β as in the first embodiment.

    That is, the manual regeneration means 62 sets the target engine speed to a low speed or medium speed (for example, 1500 to 2000 rpm) higher than the idle speed, and the fuel injection amount so that the engine speed becomes the target engine speed. Is controlled (increase the main injection amount) and sub-injection is performed to inject fuel in the expansion stroke (for example, near ATDC 50 ° CA). By increasing the main injection amount, the exhaust gas temperature is raised and the temperature of the oxidation catalyst 16 is raised to the activation temperature. Further, by executing the sub-injection, the particulates of the DPF 17 are combusted by utilizing the catalytic reaction heat in the oxidation catalyst 16 as in the case of forced regeneration.

    Regarding the detection of the stop state, when it is determined that the vehicle is stopped only when the vehicle speed is zero, or the condition that the accelerator opening is zero and the condition that the select lever is in either the P range or the N range are satisfied. It may be determined that the vehicle is stopped.

    The warning means 64 is for warning the vehicle occupant that manual regeneration of the DPF 17 is necessary, and the amount of fine particles collected in the DPF 17 based on the detection signals from the exhaust pressure sensors 18 and 19 is determined. When it is determined that the amount is equal to or greater than the fixed amount α, the warning lamp 65 is turned on.

    As in the first embodiment, the travel environment determination unit 43 determines that the host vehicle has a predetermined point (filter on the travel route) based on navigation information related to the vehicle speed when the amount of fine particles in the filter 17 exceeds a predetermined amount α. While the vehicle travels to the point where the total particulate collection amount of 17 reaches a second predetermined amount that is larger than the predetermined amount α), the temperature of the filter 17 rises and is not captured by the filter 17 without operating the manual regeneration means 62. It is determined whether or not the collected particulates are transferred to a traveling environment where they naturally burn.

    The manual regeneration suppression means 63 finishes passing through the traveling environment when the traveling environment determining means 43 determines that the traveling environment shifts to the natural combustion traveling environment while the traveling vehicle travels to the predetermined point. Until this time, the operation of the warning means 64 is prohibited.

-Control flow-
FIG. 8 shows a manual regeneration routine. In step D1 after the start, the differential pressure P between the exhaust pressures before and after the filter 17 is read by the detection signals of the exhaust pressure sensors 18 and 19, and the particulate accumulation amount M of the filter 17 is calculated based on the differential pressure P in step D2. . On the other hand, in step D3, the shift range and the vehicle speed are read.

    In a succeeding step D4, it is determined whether or not the fine particle accumulation amount M is a predetermined amount β or more. When the particulate accumulation amount M is smaller than the predetermined amount β, the forced regeneration of the filter 17 is not executed and the process returns (step D9). In the following step D5, it is determined whether or not the particulate accumulation amount M of the filter 17 is equal to or larger than a predetermined amount α, and it is determined that it is equal to or larger than the predetermined amount α and the manual regeneration switch is turned on (step D6). And when it determines with a vehicle being in a stop state (step D7), it progresses to step D8 and performs manual reproduction | regeneration. That is, after increasing the main injection amount so that the engine speed becomes 1750 rpm, sub injection (expansion stroke injection) is added. As a result, the filter 17 is regenerated using the combustion reaction heat of the fuel supplied to the oxidation catalyst 16.

    On the other hand, when it is determined in step D5 that the particulate accumulation amount M is smaller than the predetermined amount α, the process proceeds to step D10 to determine whether or not manual regeneration is currently being continued. Manual regeneration is not performed unless it is ongoing. That is, even if the amount of accumulated particulates is smaller than the predetermined amount α due to manual regeneration, the manual regeneration is continued until the amount becomes less than the predetermined amount β. Moreover, manual regeneration is not started in any of the case where it is determined in step D6 that the manual regeneration switch is not turned on, and in the case where it is determined in step D7 that the vehicle is not stopped.

    FIG. 9 shows an operation determination routine of the warning means 64 using the navigation information. As in the case of the first embodiment, the travel destination of the host vehicle is input in advance using the operation unit 56 of the navigation system 41 to set the travel route.

    In step E1 after the start, navigation information related to the vehicle speed (traffic regulation based on road traffic information such as road type and number of traffic lights based on map information, traffic congestion, presence / absence of accident) is fetched. In subsequent step E2, the differential pressure P between the exhaust pressures before and after the filter 17 is read by the detection signals of the exhaust pressure sensors 18 and 19, and the particulate accumulation amount M of the filter 17 is calculated based on the differential pressure P in step E3. In a succeeding step E4, it is determined whether or not the fine particle accumulation amount M is a predetermined amount α or more. When the particulate accumulation amount M is less than the predetermined amount α, the operation of the warning means 64 is prohibited and the process returns (step E5).

    When the particulate accumulation amount M of the filter 17 is equal to or greater than the predetermined amount α, the process proceeds to step E6, and the temperature of the filter 17 increases while the host vehicle travels to the predetermined point, as in step A6 of the first embodiment. It is then determined whether or not the traveling environment is such that the particulates naturally burn. If there is no travel environment for natural combustion between the current location and the predetermined point, the warning means 64 is activated (step E7), and if there is such a travel environment, the process proceeds to a warning means operation prohibition routine.

    FIG. 10 shows a warning means operation prohibiting routine. In step F1 after the start, navigation information related to the vehicle speed (traffic regulation based on road traffic information such as road type and number of traffic lights based on map information, traffic congestion, presence / absence of accident) is fetched. In the next step F2, the differential pressure P between the exhaust pressures before and after the filter 17 is read by the detection signals of the exhaust pressure sensors 18 and 19, and the particulate accumulation amount M of the filter 17 is calculated based on the differential pressure P in the step F3. In subsequent step F4, it is determined whether or not the fine particle accumulation amount M is equal to or larger than a second predetermined amount.

    When the fine particle accumulation amount M is greater than or equal to the second predetermined amount, the process proceeds to step F5, where the warning means 64 is operated. On the other hand, when the particulate accumulation amount M is smaller than the second predetermined amount, the process proceeds to step F6, where it is determined whether or not the passage through the section where the natural combustion traveling environment exists has been completed. Then, the process proceeds to step F8 to prohibit the operation of the warning means 64. When passing through the section where the natural combustion traveling environment exists, the warning means operation prohibiting routine is ended and the routine returns (step F7).

    Therefore, as shown in FIG. 6, in the present embodiment, the “forced regeneration suppression” section of the first embodiment is a “warning stop” section. Then, as in the first embodiment, even when the particulate accumulation amount of the filter 17 becomes equal to or larger than the predetermined amount α, the host vehicle moves to a traveling environment where natural regeneration of the filter 17 can be achieved before the second predetermined amount is reached. When there is a possibility, the operation of the warning means 64 is prohibited, and such a natural regeneration opportunity is actively used, so that the number of manual regenerations can be reduced without causing clogging of the filter. It can save energy. In addition, since the determination as to whether or not there is a possibility of shifting to the driving environment is performed in consideration of not only the map information but also the road traffic information, the determination becomes highly reliable, and the filter 17 is clogged. It is advantageous to avoid the situation that occurs.

    Further, even when it is determined that there is a natural regeneration traveling environment and the operation of the warning unit 64 is prohibited, it is determined whether or not the actual particulate accumulation amount M of the filter 17 is equal to or greater than the second predetermined amount. (Step F4), the warning means is activated when the amount exceeds the second predetermined amount, so that a sudden traffic jam or accident occurs on the travel route, or the vehicle has to stop idling. Thus, even when the amount of accumulated particulates increases unexpectedly, manual regeneration can be promoted, and clogging of the filter 17 is reliably prevented.

    In the first and second embodiments, the oxidation catalyst 16 is disposed on the upstream side of the filter 17 in order to increase the temperature of the filter 17 by the fuel injection control. By providing the above, the oxidation catalyst 16 may be omitted. Of course, the oxidation catalyst 16 may be disposed on the upstream side of the filter 17, and a catalytic metal may be supported on the filter 17 to have the function of an oxidation catalyst.

    In addition, an electric heater may be provided immediately before the filter 17 without providing the oxidation catalyst as described above, and the temperature of the filter 17 may be increased by energization from a vehicle-mounted battery. Alternatively, the electric heater and the above-described oxidation catalyst ( (Fuel injection control) may be combined.

    Further, when the filter is regenerated, an intake throttle that reduces the amount of intake air flowing into the cylinder by the intake throttle valve or an exhaust throttle that reduces the exhaust flow rate by providing a throttle valve in the exhaust passage downstream of the filter 17 is performed. Thus, the temperature of the filter 17 may be quickly increased.

    In the above embodiment, the roads are divided into three types: highways, suburban roads, and urban roads, and each particulate emission amount is corrected based on road traffic information. You may make it correct | amend based on the other parameters (for example, the number of traffic lights per unit distance, the number of intersections, a road gradient, etc.). Alternatively, it may be divided into a highway and other general roads, and for general roads, the amount of particulate emission may be defined by traffic lights per unit distance, the number of intersections, road gradients, and the like.

    The suppression of forced regeneration may be such that forced regeneration is performed in a shorter time than the normal forced regeneration time before the transition to the natural combustion traveling environment. Alternatively, in a natural combustion traveling environment, the fuel injection amount is reduced to be smaller than that in normal forced regeneration and fuel injection is performed in the expansion stroke, or the electric heater is reduced in amount to be smaller than in normal forced regeneration. The forced regeneration may be suppressed by a method of operating.

    Further, regarding the warning unit 64, the warning lamp is turned on in the second embodiment, but a warning sound may be emitted or a warning may be displayed on the display of the navigation system.

    Moreover, although the said Embodiment 1, 2 is a case where a filter is DPF, this invention is applicable also when collecting the particulates contained in the exhaust gas of a gasoline engine with a filter.

1 is a configuration diagram of an exhaust emission control device for an engine according to the present invention. 3 is a control block diagram according to Embodiment 1. FIG. It is a control flowchart of forced regeneration permission determination according to the embodiment. It is a flowchart of the forced regeneration execution routine which concerns on the same embodiment. It is a flowchart of the forced regeneration suppression routine which concerns on the same embodiment. It is a time chart figure showing change of the amount of particulates deposition of the filter concerning the present invention. 6 is a control block diagram according to Embodiment 2. FIG. It is a flowchart of the manual regeneration control of the same embodiment. It is a flowchart of the warning means operation | movement determination routine of the embodiment. It is a flowchart of the warning means operation | movement prohibition routine of the embodiment.

DESCRIPTION OF SYMBOLS 1 Engine 2 Intake passage 3 Exhaust passage 5 Cylinder combustion chamber 7 Fuel injection valve 16 Oxidation catalyst 17 Filter 18, 19 Exhaust pressure sensor 40 ECU
41 navigation system 42 forced regeneration means 43 traveling environment determination means 44 forced regeneration suppression means 52 to 54 current vehicle location detection means 56 input means 57 map information storage means 59, 60 road traffic information reception means 62 manual regeneration means 63 manual regeneration suppression Means 64 Warning means

Claims (5)

A filter provided in an exhaust passage of a vehicle engine for collecting particulates in exhaust gas;
Fine particle amount detection means for detecting a parameter value related to the amount of fine particles collected by the filter;
While the vehicle is running, the filter is configured so that the particulates collected by the filter are combusted when the particulate amount of the filter exceeds a predetermined amount based on the detection value of the particulate amount detection means. An exhaust emission control device for an engine comprising a forced regeneration means for forcibly regenerating the filter by raising the temperature of the filter,
Means for detecting the current location of the host vehicle, map information storage means, and means for inputting the travel destination of the host vehicle, and based on the map information, the travel route to the destination is determined by inputting the destination. A navigation system for setting and providing vehicle speed related information of the travel route;
When the amount of fine particles in the filter is equal to or greater than a predetermined amount, based on the vehicle speed related information of the travel route, while the host vehicle travels to a predetermined point on the travel route, the forced regeneration means does not work. Traveling environment determination means for determining whether or not the temperature of the filter rises and shifts to a traveling environment in which particulates of the filter naturally burn;
When it is determined by the traveling environment determining means that the vehicle travels to the natural combustion traveling environment while traveling to the predetermined point, the forced regeneration means continues until the host vehicle has passed the traveling environment. A forced regeneration suppression means for suppressing execution ,
The traveling environment determining means includes particulate amount data in which the particulate amount discharged from the engine per unit traveling distance is set in correspondence with the road type, and the road type of the traveling route obtained from the map information and the particulate amount Based on the data, the amount of particulates collected by the filter when traveling on the travel route is estimated, and a point at which the total particulate collection amount of the filter reaches a second predetermined amount larger than the predetermined amount is determined. An exhaust emission control device for an engine characterized by being set to the predetermined point . A filter provided in an exhaust passage of a vehicle engine for collecting particulates in exhaust gas;
Fine particle amount detection means for detecting a parameter value related to the amount of fine particles collected by the filter;
Warning means for issuing a warning to a vehicle occupant when the amount of the particulates exceeds a predetermined amount based on the detection value of the particulate amount detection means;
A manual regeneration switch for manually starting the regeneration of the filter;
When both the condition that the vehicle is in a predetermined stop state and the condition that the manual regeneration switch is turned on are satisfied, the temperature of the filter is adjusted so that the particulates collected in the filter are burned. An exhaust purification device for an engine, comprising manual regeneration means for raising and performing manual regeneration of the filter,
Means for detecting the current location of the host vehicle, map information storage means, and means for inputting the travel destination of the host vehicle, and based on the map information, the travel route to the destination is determined by inputting the destination. A navigation system for setting and providing vehicle speed related information of the travel route;
When the amount of fine particles in the filter exceeds a predetermined amount, the manual regeneration means must be operated while the host vehicle travels to a predetermined point on the travel route based on the vehicle speed related information on the travel route. Traveling environment determination means for determining whether or not the temperature of the filter rises and the transition to a traveling environment in which the particulates of the filter naturally burn,
The warning means operates until the own vehicle has passed the running environment when the running environment judging means determines that the own vehicle shifts to the spontaneous combustion running environment while the own vehicle is running to the predetermined point. Manual regeneration suppression means for prohibiting ,
The traveling environment determining means includes particulate amount data in which the particulate amount discharged from the engine per unit traveling distance is set in correspondence with the road type, and the road type of the traveling route obtained from the map information and the particulate amount Based on the data, the amount of particulates collected by the filter when traveling on the travel route is estimated, and a point at which the total particulate collection amount of the filter reaches a second predetermined amount larger than the predetermined amount is determined. An exhaust emission control device for an engine characterized by being set to the predetermined point . In claim 1 or claim 2,
The navigation system includes means for receiving road traffic information, and provides the road type based on the map information and the road traffic information as vehicle speed related information of the travel route, characterized in that it is an engine exhaust gas purification device. In claim 3 ,
The travel environment determination means corrects the particulate matter data so that the particulate matter discharged from the engine per unit travel distance increases when road traffic information that restricts the speed of the host vehicle is obtained. An exhaust purification device for an engine characterized by the above. In any one of Claims 1 thru | or 4 ,
The means for raising the temperature of the filter injects the fuel into the cylinder in the expansion stroke after the main injection in which the fuel is injected into the cylinder near the top dead center of the electric stroke or the compression stroke of the engine. An exhaust emission control device for an engine, characterized in that fuel is supplied to an oxidation catalyst disposed upstream of the filter, and the filter is heated by combustion reaction heat of the fuel in the oxidation catalyst.

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