JP6908560B2 - Diesel engine exhaust treatment system - Google Patents

Description

The present invention relates to an exhaust treatment device for a diesel engine, and more particularly to a device capable of detecting an abnormality in the exhaust treatment device due to forgetting to install a DPF or extracting a DPF.

Conventionally, as an exhaust treatment device for a diesel engine, there is a device provided with a DPF arranged in an exhaust path and an ash accumulation amount estimation device for estimating the accumulation amount of ash deposited on the DPF (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-202573 (see FIGS. 1 and 2)

In Patent Document 1, even if there is an abnormality due to forgetting to install the DPF or extracting the DPF, it cannot be detected.

An object of the present invention is to provide an exhaust gas treatment device for a diesel engine capable of detecting an abnormality of the exhaust gas treatment device due to forgetting to install the DPF or extracting the DPF.

(Major invention-specific matters common to the inventions according to claims 1 and 3)
The main invention-specific matters common to the inventions according to claims 1 and 3 are as follows.
The DPF presence / absence evaluation map includes a presence / absence boundary region formed over the low differential pressure low exhaust side and the high differential pressure high exhaust side, and a presence / absence evaluation region on the low differential pressure high exhaust side rather than the presence / absence boundary region. The presence evaluation region on the high differential pressure and low exhaust side of the boundary region is provided, the absence evaluation value is assigned to the absence evaluation region, and the presence evaluation value is assigned to the presence evaluation region. It is configured to determine the existence or nonexistence of the DPF based on the aggregated result of the existence evaluation value and the nonexistence evaluation value read from the DPF existence evaluation map corresponding to the pressure and the exhaust flow rate.
(Invention-specific matters specific to the invention according to claim 1)
The matters specifying the invention peculiar to the invention according to claim 1 are as follows.
A diesel engine exhaust treatment device characterized in that the existence evaluation value of the existence evaluation area is set to a higher evaluation value than the absence evaluation value of the absence evaluation area.
(Invention-specific matters specific to the invention according to claim 3)
The non-existence evaluation region includes a near-boundary non-existence evaluation region adjacent to the existence / non-existence boundary region and a far-boundary non-existence evaluation region adjacent to the near-boundary non-existence evaluation region on the low differential pressure multi-exhaust side. The non-existence evaluation value of the region is set to a value having a higher non-existence evaluation than the non-existence evaluation value of the near-boundary non-existence evaluation region.
The existence evaluation area includes a near boundary existence evaluation area adjacent to the existence / non-existence boundary area and a far boundary existence evaluation area adjacent to the near boundary existence evaluation area on the high differential pressure low exhaust side, and the existence evaluation value of the far boundary existence evaluation area. Is a diesel engine exhaust treatment device characterized in that the existence evaluation is set to a value higher than the existence evaluation value in the near boundary existence evaluation region.
(Desirable invention identification matter)
It is desirable that the presence / absence determination of the DPF is performed so as to be performed when a predetermined aggregation time measured by the timekeeping device has elapsed.

(Effects common to the inventions according to claims 1 and 3)
The effects common to the inventions according to claim 1 and claim 3 are as follows.
Since it is possible to determine the presence or absence of the DPF, it is possible to detect an abnormality in the exhaust treatment device due to forgetting to install the DPF or extracting the DPF.
In addition, the existence evaluation value of the absence evaluation area on the low differential pressure multi-exhaust side with high credibility of the absence of DPF and the existence evaluation area of the existence evaluation area on the high differential pressure low exhaust side with high credibility of the existence of DPF. Since the values are aggregated to determine the existence or nonexistence of the DPF, the accuracy of the existence or nonexistence determination of the DPF can be improved.
(Effects specific to the invention according to claim 1)
The effects peculiar to the invention according to claim 1 are as follows.
In the invention according to claim 1, since the existence evaluation value is set to a higher evaluation value than the non-existence evaluation value, erroneous determination of non-existence determination is unlikely to occur, and fraud such as extraction of DPF of the engine user is suspected. It is possible to improve the accuracy of the non-existence determination and prevent the engine user from being unjustly suspected.
(Effects specific to the invention according to claim 3)
The effects peculiar to the invention according to claim 3 are as follows.
In the invention according to claim 3, the existence / non-existence evaluation is set to a high value in the far-boundary non-existence evaluation region in which the credibility of the DPF nonexistence evaluation is high and in the far-boundary existence evaluation region in which the existence evaluation is highly credible. Therefore, the accuracy of determining the existence or nonexistence of the DPF is improved.

It is a schematic diagram of the engine which concerns on embodiment of this invention. It is a figure explaining the existence or absence map of the DPF used in the engine which concerns on embodiment of this invention, and FIG. A diagram showing the existence / non-existence evaluation value, FIG. 2 (B) is a diagram in which a graph showing the characteristics of the exhaust flow rate and the differential pressure of the new DPF and the region partitioned on the map is superimposed. FIG. 3A is a diagram showing a region partitioned on the map and a grid point D of a specific exhaust flow rate and a specific differential pressure. It is a flowchart of the existence / absence determination process of DPF by the electronic control device of the engine which concerns on embodiment of this invention. It is a flowchart of the DPF regeneration process by the electronic control device of the engine which concerns on embodiment of this invention.

1 to 5 are views for explaining an engine according to an embodiment of the present invention, and in this embodiment, a vertical water-cooled in-line 4-cylinder diesel engine provided with an exhaust treatment device will be described.

The outline of this engine is as follows.
As shown in FIG. 1, this engine includes a cylinder block (11), a cylinder head (12) assembled on the upper part of the cylinder block (11), and a fly wheel (11) provided on the rear part of the cylinder block (11). 13), an engine cooling fan (14) provided at the front of the cylinder block (11), an intake manifold (not shown) arranged on one side of the cylinder head (12), and a cylinder head (12). ), An exhaust manifold (16) arranged on the other side, a supercharger (17) connected to the exhaust manifold (16), and an exhaust treatment case provided on the downstream side of the exhaust of the supercharger (17). (18), a fuel supply device (19a), and an electronic control device (20) are provided.

The outline of the intake device is as follows.
As shown in FIG. 1, the intake device includes a compressor (17a) of a supercharger (17), an air cleaner (21) arranged on the intake upstream side of the compressor (17a), an air cleaner (21), and a compressor (17a). ), An intercooler (23) arranged on the intake downstream side of the compressor (17a), and an intake throttle valve (23) arranged on the intake downstream side of the intercooler (23). 24) and an intake manifold (not shown) arranged on the intake downstream side of the intake throttle valve (24) are provided.
The air flow sensor (22) and the electric actuator (24a) of the intake throttle valve (24) are electrically connected to the electronic control device (20).
An engine ECU is used in the electronic control device (20). ECU is an abbreviation for electronic control unit and is a microcomputer.

The outline of the fuel supply device (19a) is as follows.
As shown in FIG. 1, the fuel supply device (19a) is a common rail type, and has a plurality of fuel injectors (25) inserted into each cylinder and a common rail (25) for distributing the accumulated fuel to the plurality of fuel injectors (25). It includes a fuel supply pump (27) for pumping fuel to the common rail (26), and a fuel tank (28).
The fuel supply pump (27) and the solenoid valve (25a) of the fuel injector (25) are electrically connected to the electronic control device (20). An accelerator sensor (29), a crankshaft sensor (30), and a cylinder discrimination sensor (31) are electrically connected to the electronic control device (20). The accelerator sensor (29) detects the target rotation speed of the engine, and the crankshaft sensor (30) detects the actual rotation speed and crank angle of the engine. The cylinder discrimination sensor (31) detects the combustion stroke of each cylinder.

In the fuel supply device (19a), the engine load is calculated by the electronic control device (20) based on the deviation between the target rotation speed and the actual rotation speed of the engine, and the fuel injector is calculated according to the target rotation speed and the engine load of the engine. The electromagnetic valve (25a) of (25) is opened at a predetermined timing for a predetermined time, and a predetermined amount of fuel (32) is injected from the fuel injector (25) into each cylinder at a predetermined timing. The fuel (32) is light oil.

As shown in FIG. 1, the accelerator sensor (29) detects a target rotation speed setting position of the accelerator lever (29a), and a potentiometer is used for the accelerator sensor (29).

As shown in FIG. 1, the crankshaft sensor (30) detects the passage of the protrusion of the crankshaft detection disc (30a) attached to the flywheel (13). The crankshaft detection disc (30a) is provided with one starting point protrusion on the peripheral edge and a large number of phase protrusions provided at equal pitches, and the actual engine rotation is performed by the electronic control device (20) based on the passing speed of these protrusions. The number is calculated, and the crank angle is calculated based on the phase difference between the passing phase protrusion and the starting protrusion.
The cylinder discrimination sensor (31) detects the passage of the protrusion of the cylinder discrimination disc (31a) attached to the valve drive cam shaft (not shown). The cylinder discriminating disk (31a) is provided with one protrusion on the peripheral edge, and the electronic control device (20) discriminates the combustion stroke of four cycles based on the passage of the protrusion.
An electromagnetic pickup sensor is used for the crankshaft sensor (30) and the cylinder discrimination sensor (31).

The outline of the exhaust system is as follows.
As shown in FIG. 1, the exhaust device includes an exhaust manifold (16), an exhaust turbine (17b) of a supercharger (17) provided on the exhaust downstream side of the exhaust manifold (16), and an exhaust turbine (17b). It is provided with an exhaust treatment device (33) provided on the downstream side of the exhaust gas. A series of paths from the exhaust manifold (16) to the exhaust treatment device (33) is the exhaust path (1).

The outline of the exhaust treatment device (33) is as follows.
The exhaust treatment device (33) is arranged on the exhaust upstream side in the exhaust treatment case (18) and the exhaust treatment case (18) provided on the exhaust downstream side of the exhaust turbine (17b) of the supercharger (17). It is provided with a DOC (35) and a DPF (2) arranged on the downstream side of the exhaust in the exhaust treatment case (18).

DPF is an abbreviation for diesel particulate filter, which captures PM in engine exhaust. PM is an abbreviation for particulate matter. As shown in FIG. 1, a large number of cells (2a) along the axial length direction are arranged side by side in the DPF (2), and the inlets and outlets of the adjacent cells (2a) and (2a) are alternately sealed. A wall-flow type ceramic honeycomb is used.
DOC is an abbreviation for diesel oxidation catalyst, which oxidizes CO (carbon monoxide) and NO (nitric oxide) in engine exhaust. For the DOC (35), a flow-through type ceramic honeycomb in which a large number of cells (35a) along the axial length direction are arranged side by side in a penetrating manner is used, and the cells are oxidized with rhodium of platinum or palladium. The catalyst component is supported.

The exhaust gas treatment device (33) includes a regeneration device (R) of the DPF (2).
The regeneration device (R) of the DPF (2) includes a PM deposition amount estimation device (4) that estimates the amount of PM deposited on the DPF (2), an exhaust gas heating device (19), and an electronic control device (20). ) Is provided, and the electronic control device (20) is configured to perform the regeneration process of the DPF (2) based on the PM accumulation amount of the DPF (2) reaching a predetermined regeneration required value. In the regeneration process of), the exhaust gas (39) is heated by the exhaust gas heating device (19), and the PM deposited on the DPF (2) is incinerated.

The PM accumulation amount estimation device (4) is composed of an electronic control device (20), and the differential pressure detected by the differential pressure sensor (3) that detects the differential pressure between the exhaust inlet side and the exhaust outlet side of the DPF (2). Based on, the amount of PM deposited on the DPF (2) is estimated. Instead of the differential pressure of the DPF (2), the accumulated amount of PM accumulated on the DPF (2) may be estimated based on the integrated value of the engine operating time and the integrated value of the fuel supply amount.
The exhaust temperature raising device (19) includes an intake throttle valve (24), a fuel supply device (19a), an DOC (35), and an exhaust on the DOC inlet side that detects the exhaust temperature on the exhaust inlet side of the DOC (35). The temperature sensor (37), the exhaust temperature sensor (36) on the DPF outlet side that detects the exhaust temperature on the exhaust outlet side of the DPF (2), and the DPF inlet side that detects the exhaust temperature on the exhaust inlet side of the DPF (2). Exhaust temperature sensor (38) is provided.
Each of the above sensors (36), (37), and (38) is electrically connected to the electronic control device (20).

As shown in FIG. 1, in the exhaust treatment device (33), the DPF (2) captures the PM in the engine exhaust (39), and the NO (nitrogen monoxide) in the exhaust (39) is converted by the DOC (35). _{With NO 2} (nitrogen dioxide) obtained by oxidation, PM deposited on the DPF (2) is continuously oxidatively combusted at a relatively low temperature, and the differential pressure detected by the differential pressure sensor (3) is a predetermined regeneration. Based on the required value, the unburned fuel supplied to the exhaust (39) by the post-injection of the common rail type fuel supply device (19a) under the control of the electronic control device (20) is DOC (35). The exhaust gas (39) is heated, and the PM deposited on the DPF (2) is burned at a relatively high temperature to regenerate the DPF (2).
When the exhaust temperature is low and the exhaust temperature on the inlet side of the DOC (35) does not reach the activation temperature of the DOC (35), the intake throttle valve (24) is throttled by the control of the electronic control device (20). , The exhaust temperature is raised.

The start time of the DPF regeneration process is as follows.
When the differential pressure detected by the differential pressure sensor (3) reaches the required regeneration value, the exhaust temperature on the inlet side of the DOC (35) has reached the activation temperature of the DOC (35), and at that point, post-injection is performed. Is started, the start time of the post injection becomes the start time of the regeneration process of the DPF.
When the differential pressure detected by the differential pressure sensor (3) reaches the required regeneration value, the exhaust temperature on the inlet side of the DOC (35) has not reached the activation temperature of the DOC (35), and the intake throttle valve (3) When 24) is throttled, the throttle start time of the intake throttle valve (24) becomes the start time of the DPF regeneration process. In this case, the time when the inlet side exhaust temperature of the DOC (35) reaches the activation temperature of the DOC (35) and the post injection is started may be defined as the start time of the DPF regeneration process.

Instead of the post-injection of the common rail type fuel supply device (19a), an exhaust pipe fuel injector (not shown) arranged between the exhaust turbine (17b) and the DOC (35) of the supercharger (17) is used. Exhaust pipe injection that injects unburned fuel into the exhaust (39) may be used. Further, instead of the post injection of the common rail type fuel supply device (19a), the exhaust temperature may be raised by the heat generated by the electric heater or the exhaust throttle of the exhaust throttle valve.

As shown in FIG. 1, this engine includes a DPF (2) arranged in the exhaust path (1), a differential pressure sensor (3) for detecting the differential pressure between the exhaust inlet and the exhaust outlet of the DPF (2), and a differential pressure sensor (3). It is provided with an exhaust flow rate calculation device (9) for calculating the exhaust gas flow rate passing through the DPF (2), a DPF presence / absence evaluation map (7), and a DPF presence / absence determination device (10) for determining the presence / absence of the DPF (2). ..

As shown in FIG. 2, the DPF presence / absence evaluation map (7) has a presence / absence boundary region (7a) formed over the low differential pressure low exhaust side and the high differential pressure high exhaust side, and the presence / absence boundary region (7a). The absence evaluation region (7b) on the low differential pressure high exhaust side and the presence evaluation region (7c) on the high differential pressure low exhaust side than the existence boundary region (7a) are provided in the nonexistence evaluation region (7b). Is assigned an absent evaluation value, and an existence evaluation value is assigned to the existence evaluation area (7c).
The DPF presence / absence determination device (10) has the presence / absence of the DPF (2) based on the aggregated results of the presence / absence evaluation values and the absence evaluation values read from the DPF presence / absence evaluation map (7) corresponding to the differential pressure and the exhaust flow rate. Is configured to determine.

Since the presence or absence of the DPF (2) can be determined in this engine, it is possible to detect an abnormality in the exhaust treatment device due to forgetting to install the DPF (2) or extracting the DPF (2).
Further, the absence evaluation value of the absence evaluation region (7b) on the low differential pressure high exhaust side with high credibility of the absence of the DPF (2) and the high differential pressure with high credibility of the existence of the DPF (2) are low. Since the existence evaluation value of the existence evaluation area (7c) on the exhaust side is aggregated to determine the existence / nonexistence of the DPF (2), the accuracy of the existence / absence determination of the DPF (2) can be improved.

As shown in FIG. 1, this engine is provided with a time measuring device (5), and as shown in FIG. 4, the presence or absence of the DPF (2) is determined by the passage of a predetermined totaling time measured by the time measuring device (5). It is configured to be done from time to time.
In this engine, since the determination is made when a predetermined aggregation time has elapsed, it is possible to avoid an unnecessary extension of the determination time.

Results As shown in FIG. 2, in the existence / non-existence boundary region (7a) of the DPF existence / non-existence evaluation map (7), a non-existence / non-existence evaluation value in which the existence / non-existence of the DPF (2) is not evaluated is assigned.
In this engine, since the existence / non-existence evaluation value is assigned in the existence / non-existence boundary region (7a) where the existence / non-existence evaluation of the DPF (2) is uncertain, the accuracy of the existence / non-existence determination of the DPF (2) can be improved.

As shown in FIG. 2, the existence evaluation value of the existence evaluation region (7c) is set to a high evaluation value equal to or higher than the absence evaluation value of the absence evaluation region (7b).
In this engine, since the existence evaluation value is set to a higher evaluation value than the non-existence evaluation value, erroneous determination of non-existence judgment is unlikely to occur, and fraud such as extraction of the DPF (2) of the engine user is suspected. It is possible to improve the accuracy of the absence determination and prevent the engine user from being unjustly suspected.

As shown in FIG. 2, the non-existence evaluation region (7b) has a low differential pressure in the near-boundary non-existence evaluation region (7d) adjacent to the existence / non-existence boundary region (7a) and the near-boundary non-existence evaluation region (7d). It is provided with an adjacent far boundary absence evaluation region (7e) on the exhaust side, and the absence evaluation value of the far boundary absence evaluation region (7e) is less than the absence evaluation value of the near boundary absence evaluation region (7d). The existence evaluation is set to a high value.
The existence evaluation region (7c) includes a near-boundary existence evaluation region (7f) adjacent to the existence / non-existence boundary region (7a) and a far-boundary existence evaluation region (7f) adjacent to the near-boundary existence evaluation region (7f) with high differential pressure and low exhaust gas. 7g) is provided, and the existence evaluation value of the far boundary existence evaluation region (7g) is set to a value higher than the existence evaluation value of the near boundary existence evaluation region (7f).
In this engine, the existence / non-existence evaluation is high in the far-boundary non-existence evaluation region (7e) where the credibility of the nonexistence evaluation of the DPF (2) is high and in the far-boundary existence evaluation region (7g) where the credibility of the existence evaluation is high. Since it is set to, the accuracy of determining the existence or nonexistence of the DPF (2) is improved.

As shown in FIG. 1, the non-existence notification device (8) is provided, and when the non-existence of the DPF (2) is determined, the electronic control device (20) uses the non-existence notification device (8) to perform the DPF ( It is configured to notify the absence of 2).
In this engine, the engine user can be advised that the DPF (2) needs to be installed by notifying the absence of the DPF (2).

As shown in FIG. 1, when the non-volatile storage medium (6) is provided and the absence of the DPF (2) is determined, the electronic control device (20) determines the non-volatile storage medium (6). Is configured to memorize.
In this engine, since the determination of the absence of the DPF (2) is stored in the non-volatile storage medium (6), the history of the determination of the absence of the DPF (2) can be confirmed after the fact.

As shown in FIG. 1, the non-volatile storage medium (6) and the timekeeping device (5) are built in the electronic control device (20). The PM accumulation amount estimation device (4), the exhaust flow rate calculation device (9), and the DPF presence / absence determination device (10) are composed of an electronic control device (20).
As the non-volatile storage medium (6), a flash memory, P-ROM, EP-ROM, or E2P-ROM can be used.
The absence notification device (8) is composed of an alarm lamp electrically connected to the electronic control device (20), and the alarm is issued by lighting the alarm lamp. A light emitting diode is used for the alarm lamp.
As the absence notification device (8), a display such as a liquid crystal display or an organic EL display can be used instead of the alarm lamp, and the alarm may be issued by displaying characters, figures, and symbols. EL is an abbreviation for electroluminescence.
As the absence notification device (8), an alarm buzzer, an alarm sound generator such as an alarm bell, or the like can be used instead of the alarm lamp, and the alarm may be emitted by the alarm sound.

The determination of the absence of the DPF (2) stored in the non-volatile storage medium (6) is stored as abnormal data by the failure diagnosis code.
The abnormal data stored in the non-volatile storage medium (6) is read from the non-volatile storage medium (6) by the failure diagnosis tool based on the inspection by the serviceman, the report request from the regulatory authority, etc., and the DPF (2) The non-volatile history is confirmed after the fact.
The fault diagnosis code is indicated by a multi-digit number or symbol.
As the failure diagnosis tool, a laptop computer or a portable terminal on which a failure diagnosis program is installed can be used.

The presence / absence evaluation value corresponding to the exhaust flow rate and the differential pressure is assigned to the DPF presence / absence evaluation map.
The existence / non-existence evaluation values shown in FIG. 2A are assigned to the grid points of the specific exhaust flow rate and the specific differential pressure. For example, the grid points of the exhaust flow rate of 15 (kg / h) and the differential pressure of 0 (kPa) are assigned. The absence evaluation value of 1 is assigned, and the presence evaluation value of -5 is assigned to the grid points at the exhaust flow rate of 0 (kg / h) and the differential pressure of 10 (kPa).
In the case of the operating state in the middle of each grid point, the optimum value is complemented and determined from a plurality of points on the map.

As shown in FIG. 1, the engine includes an airflow sensor (22), an atmospheric pressure sensor (40), and a fuel supply map (15).
The electronic control device (20) includes an intake flow rate measured by an air flow sensor (22), an atmospheric pressure detected by an atmospheric pressure sensor (40), a differential pressure detected by a differential pressure sensor (3), and fuel. The exhaust flow rate calculation device (9) is configured to calculate the exhaust flow rate based on the fuel supply amount measured in the supply map (15).
The fuel supply map (15) is stored in the non-volatile storage medium (6), and the fuel supply amount corresponding to the engine speed and the engine load is input to the fuel supply map (15).
In this case, since the exhaust flow rate is calculated based on the intake flow rate, the atmospheric pressure, the differential pressure, and the fuel supply amount, it is possible to accurately estimate the exhaust flow rate.
The exhaust flow rate is the exhaust volume flow rate per unit time, and is obtained by converting the intake air flow rate measured by the air flow sensor (22).

In this engine, instead of the precise estimation of the exhaust gas flow rate, a simple estimation of the exhaust gas flow rate may be performed.
That is, this engine includes an air flow sensor (22), and the electronic control device (20) regards the intake air flow rate measured by the air flow sensor (22) as an exhaust flow rate, and the exhaust flow rate calculation device (9) determines the exhaust flow rate. May be calculated.
In this case, since the exhaust flow rate is calculated by regarding the intake flow rate as the exhaust flow rate, the exhaust flow rate can be easily estimated.

The procedure for processing the presence / absence determination of the DPF by the electronic control device will be described with reference to the flowchart of FIG.
As shown in FIG. 4, in step (S1), it is determined whether or not the aggregation start condition is satisfied, the determination is repeated until the determination is affirmed, and when the determination is affirmed, the process proceeds to step (S2).
The aggregation start condition is that the integrated value of the engine operating time after the engine is shipped reaches the predetermined value, and then the integrated value of the engine operating time is the predetermined value (0) from the time of the previous determination of the existence of the DPF. It is when the value that exceeds) is reached.
In step (S2), the existence / non-existence evaluation values of the DPF read from the existence / non-existence evaluation map are totaled according to the differential pressure and the exhaust flow rate, the process proceeds to step (S3), and the predetermined totaling time elapses in step (S3). If it is determined whether or not the determination has been made and the determination is affirmed, the process proceeds to step (S4), and if the determination is denied, the process returns to step (S2).
In step (S4), the existence or nonexistence of the DPF is determined, and in step (S5), it is determined whether or not the nonexistence of the DPF is determined. If the determination is affirmed, the process proceeds to step (S6) to determine. If is affirmed, the process returns to step (S1).

In step (S6), the absence of the DPF is stored in the non-volatile medium (6), the process proceeds to step (S7), the absence notification device (8) starts notification of the absence of the DPF, and step (S8). ) Determines the existence of the DPF. The determination in step (S8) is repeated until the determination is affirmed, and when the determination is affirmed, the notification of the absence of the DPF is terminated in step (S9).
Similar to steps (S2) to (S4), the determination of existence in the DPF in step (S8) is performed when the existence / non-existence evaluation values of the DPF of the existence / non-existence evaluation map are totaled and a predetermined totaling time has elapsed.

The procedure of the DPF regeneration process by the electronic control device (20) will be described with reference to the flowchart of FIG.
As shown in FIG. 5, it is determined in step (S11) whether or not the estimated value of PM deposited on the DPF (2) has reached the required regeneration value. The determination in step (S11) is repeated until the determination is affirmed, and when the determination is affirmed, it is determined in step (S12) whether or not the DOC (35) has reached the activation temperature, and the determination is affirmed. In step (S13), the regeneration of the DPF (2) is started, and in the step (S14), it is determined whether or not the regeneration end condition of the DPF (2) is satisfied. The process is completed, and if the determination is denied, the process returns to step (S12).

The regeneration end condition is that the integrated time at which the DPF inlet exhaust temperature maintains a predetermined regeneration required temperature (for example, around 500 ° C.) reaches a predetermined end set time (for example, 20 minutes) by post injection.
If the exhaust temperature on the DPF outlet side reaches an abnormally high temperature (for example, around 700 ° C) during the regeneration of the DPF (2), the post injection is stopped in order to avoid thermal damage to the DPF (2). ..

If the inlet side exhaust temperature of the DOC (35) does not reach the activation temperature of the DOC (35) in the step (S12), the exhaust (S15) is performed by the intake throttle by the intake throttle valve (24) in the step (S15). 39) is heated, and the process returns to step (S12).

(1) ... Exhaust path, (2) ... DPF, (3) ... Differential pressure sensor, (5) ... Timekeeping device, (6) ... Non-volatile storage medium, (7) ... DPF existence evaluation map, (7a) ... Existence / non-existence boundary region, (7b) ... Absence evaluation region, (7c) ... Existence evaluation region, (7d) ... Near boundary nonexistence evaluation region, (7e) ... Far boundary nonexistence evaluation region, (7f) ... Near boundary existence Evaluation area, (7 g) ... Far boundary existence evaluation area, (8) ... Absence notification device, (9) ... Exhaust gas flow calculation device, (10) ... DPF presence / absence determination device.

Claims (7)

The DPF (2) arranged in the exhaust path (1), the differential pressure sensor (3) for detecting the differential pressure between the exhaust inlet and the exhaust outlet of the DPF (2), and the exhaust flow rate passing through the DPF (2) are calculated. The exhaust flow calculation device (9), the DPF existence evaluation map (7), and the DPF existence determination device (10) for determining the existence of the DPF (2) are provided.
The DPF existence / non-existence evaluation map (7) shows the existence / non-existence boundary region (7a) formed over the low differential pressure low exhaust side and the high differential pressure multi-exhaust side, and the existence / non-existence boundary region (7a). The absence evaluation region (7b) on the side and the existence evaluation region (7c) on the exhaust side with a higher differential pressure and less than the existence boundary region (7a) are provided, and the absence evaluation value is set in the absence evaluation region (7b). Existence evaluation values are assigned to the existence evaluation areas (7c), respectively.
The DPF presence / absence determination device (10) has the presence / absence of the DPF (2) based on the aggregated results of the presence / absence evaluation values and the absence evaluation values read from the DPF presence / absence evaluation map (7) corresponding to the differential pressure and the exhaust flow rate. Is configured to determine
An exhaust treatment device for a diesel engine, characterized in that the presence evaluation value of the presence evaluation region (7c) is set to a higher evaluation value equal to or higher than the absence evaluation value of the absence evaluation region (7b). In the diesel engine exhaust treatment device according to claim 1,
The absence evaluation region (7b) includes a near boundary absence evaluation region (7d) adjacent to the existence boundary region (7a) and a far boundary adjacent to the near boundary absence evaluation region (7d) on the low differential pressure multi-exhaust side. The absence evaluation region (7e) is provided, and the absence evaluation value of the far boundary absence evaluation region (7e) is set to a value having a higher absence evaluation than the absence evaluation value of the near boundary absence evaluation region (7d). Being done
The existence evaluation area (7c) includes a near boundary existence evaluation area (7f) adjacent to the existence / absence boundary area (7a) and a far boundary existence evaluation area (7f) adjacent to the near boundary existence evaluation area (7f) on the high differential pressure low exhaust side. (7g) is provided, and the existence evaluation value of the far boundary existence evaluation region (7g) is set to a value higher than the existence evaluation value of the near boundary existence evaluation region (7f). Exhaust treatment equipment for diesel engines. The DPF (2) arranged in the exhaust path (1), the differential pressure sensor (3) for detecting the differential pressure between the exhaust inlet and the exhaust outlet of the DPF (2), and the exhaust flow rate passing through the DPF (2) are calculated. The exhaust flow calculation device (9), the DPF existence evaluation map (7), and the DPF existence determination device (10) for determining the existence of the DPF (2) are provided.
The DPF existence / non-existence evaluation map (7) shows the existence / non-existence boundary region (7a) formed over the low differential pressure low exhaust side and the high differential pressure multi-exhaust side, and the existence / non-existence boundary region (7a). The absence evaluation region (7b) on the side and the existence evaluation region (7c) on the exhaust side with a higher differential pressure and less than the existence boundary region (7a) are provided, and the absence evaluation value is set in the absence evaluation region (7b). Existence evaluation values are assigned to the existence evaluation areas (7c), respectively.
The DPF presence / absence determination device (10) has the presence / absence of the DPF (2) based on the aggregated results of the presence / absence evaluation values and the absence evaluation values read from the DPF presence / absence evaluation map (7) corresponding to the differential pressure and the exhaust flow rate. Is configured to determine
The absence evaluation region (7b) includes a near boundary absence evaluation region (7d) adjacent to the existence boundary region (7a) and a far boundary adjacent to the near boundary absence evaluation region (7d) on the low differential pressure multi-exhaust side. The absence evaluation region (7e) is provided, and the absence evaluation value of the far boundary absence evaluation region (7e) is set to a value having a higher absence evaluation than the absence evaluation value of the near boundary absence evaluation region (7d). Being done
The existence evaluation area (7c) includes a near boundary existence evaluation area (7f) adjacent to the existence / absence boundary area (7a) and a far boundary existence evaluation area (7f) adjacent to the near boundary existence evaluation area (7f) on the high differential pressure low exhaust side. (7g) is provided, and the existence evaluation value of the far boundary existence evaluation region (7g) is set to a value higher than the existence evaluation value of the near boundary existence evaluation region (7f). Exhaust treatment equipment for diesel engines. In the diesel engine exhaust treatment device according to any one of claims 1 to 3.
Equipped with a timekeeping device (5)
A diesel engine exhaust treatment device, characterized in that the presence or absence of the DPF (2) is determined so as to be performed when a predetermined aggregation time measured by the time measuring device (5) has elapsed. In the diesel engine exhaust treatment device according to any one of claims 1 to 4.
An exhaust treatment device for a diesel engine, characterized in that, in the existence / non-existence boundary region (7a) of the DPF existence / non-existence evaluation map (7), a non-existence / non-existence evaluation value in which the existence / non-existence of the DPF (2) is not evaluated is assigned. In the diesel engine exhaust treatment device according to any one of claims 1 to 5.
Equipped with an absence notification device (8)
When the absence of the DPF (2) is determined, the electronic control device (20) is configured to notify the absence of the DPF (2) by the absence notification device (8). Diesel engine exhaust treatment system. In the diesel engine exhaust treatment device according to claim 1 to 6.
Equipped with a non-volatile storage medium (6)
A diesel engine characterized in that, when the absence of the DPF (2) is determined, the electronic control device (20) is configured to store the determination result in the non-volatile storage medium (6). Exhaust treatment device.

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