JPH07317529A - Exhaust emission control device of diesel engine - Google Patents

Abstract

PURPOSE:To provide an exhaust emission control device for diesel engine, which can judge erroneous sensing of the particulate collecting amount. CONSTITUTION:A filter 5 is installed in the exhaust pipe 2 of a diesel engine 1, and an ECU 19 calculates the particulate collecting amount Pmq1 of the filter 5 from the pressure difference between upstream and downstream of filter, also calculates the particulate collecting amount Pmq2 from the exhaust gas temp. and the engine speed, and judges whether the difference between two calculation lies within the specified range. If outside the specified range, judgement is passed that the value of Pmq1 is abnormal. In a normal case, the filter 5 is regenerated when the collecting amount Pmql at the filter 5 exceeds a specified level-in abnormal case, alarm is issued by lighting an alarm lamp 20, and the filter is regenerated when the collecting amount Pmq2 exceeds a certain specified value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust emission control device for a diesel engine.

[0002]

2. Description of the Related Art D as a measure against black smoke in diesel engines
A PF (diesel particulate filter) system is adopted. This is as shown in FIG.
The exhaust system of the diesel engine 31 is provided with a filter 32 for collecting particulates, the pressure sensor 33 detects the pressure on the upstream side of the filter 32, and the pressure sensor 34 detects the pressure on the downstream side of the filter 32. ECU
35 calculates the amount of particulates trapped in the filter 32 from the pressure difference between the upstream side and the downstream side of the filter 32, and when a certain amount or more of particulates are trapped, the filter clogging is eliminated. Burn the collected particulates. As a method of this filter regeneration, the ECU 3
By energizing the electric heater 36 at 5, the filter 3
The particulates collected in 2 are ignited, and the electromagnetic valve 37 is opened to drive the electric air pump 38 to supply secondary air (oxygen) to the filter 32 and be collected in the filter 32. It was supposed to incinerate particulates.

[0003]

However, the pressure guiding tube 33a of the pressure sensor 33 and the pressure guiding tube 34a of the pressure sensor 34 may be clogged, and when the pressure guiding tubes 33a, 34a are clogged, the particulate collection amount is erroneously detected. Is done
It becomes difficult to perform a regeneration process with a desired particulate collection amount.

Therefore, an object of the present invention is to provide an exhaust emission control device for a diesel engine, which can determine erroneous detection of the amount of collected particulates.

[0005]

According to a first aspect of the present invention, there is provided a filter provided in an exhaust system of a diesel engine for collecting particulates, and the particulates collected by the filter are burned to incinerate the same. And a regenerating means for regenerating the filter, calculating the amount of particulates collected in the filter from the pressure difference between the upstream side and the downstream side of the filter, the amount of particulates collected is a predetermined value With the above, in the exhaust gas purification apparatus of the diesel engine configured to regenerate the filter by the regenerating means, the operating state detecting means for detecting the operating state of the diesel engine, and the operating state of the diesel engine by the operating state detecting means A comparative collection amount calculation means for calculating a collection amount of particulates in the filter, and a comparison collection amount calculation hand. The amount of particulates collected by the above and the amount of particulates collected from the pressure difference are compared to determine whether the amount of deviation between the two is within a predetermined range. The gist is an exhaust emission control device for a diesel engine, which includes a determination unit that determines that the amount of collected particulates is abnormal.

According to a second aspect of the present invention, when the determination means in the first aspect of the invention determines that there is an abnormality, the amount of particulates trapped by the comparative trapping amount calculation means is predetermined. When the value is equal to or more than the value, the gist is an exhaust emission control device of a diesel engine equipped with a regeneration control unit that regenerates the filter by the regeneration unit.

A third aspect of the present invention is directed to an exhaust emission control device for a diesel engine, which is equipped with an alarm means for issuing an alarm when the determination means in the first aspect of the invention determines that there is an abnormality. To do.

According to a fourth aspect of the present invention, the comparative trapping amount calculating means in the first aspect of the invention has a correcting means for correcting the trapping amount of particulates according to the temperature of the filter during regeneration. The subject is an exhaust emission control system for diesel engines.

[0009]

According to the present invention, the operating condition detecting means detects the operating condition of the diesel engine, and the comparative trapping amount calculating means detects the operating condition of the diesel engine by the operating condition detecting means. Calculate the amount of curate collected. Then, the judging means compares the collected amount of particulates by the comparative collected amount calculating means with the collected amount of particulates from the pressure difference and determines whether the deviation amount between the two is within a predetermined range. It is determined that the amount of particulates trapped from the pressure difference is abnormal if the amount is out of the predetermined range.

According to a second aspect of the invention, in addition to the operation of the first aspect of the invention, when the regeneration control means determines that there is an abnormality by the determination means, the particulate matter by the comparison trap amount calculation means is used. When the collection amount of is equal to or more than a predetermined value, the filter is regenerated by the regenerating means.

According to a third aspect of the invention, in addition to the operation of the first aspect of the invention, the alarm means issues an alarm when the determination means determines that there is an abnormality. According to the invention described in claim 4, in addition to the operation of the invention described in claim 1, the correcting means corrects the trapped amount of the particulates by the temperature of the filter at the time of regeneration. As a result, it becomes possible to more accurately determine the trapped amount of particulates.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall configuration diagram of an exhaust emission control device for a diesel engine.

A four-stroke diesel engine 1 is mounted on a vehicle. The diesel engine 1 is supplied with high-pressure fuel from a column fuel injection pump and is injected in a combustion chamber. A housing 4 of an exhaust emission control device 3 is provided in the exhaust pipe 2 of the diesel engine 1. The housing 4 communicates with the exhaust pipe 2, and exhaust gas of the diesel engine 1 passes through the housing 4. A filter (DPF) 5 is provided in the housing 4, and the filter 5
At, particulates discharged from the diesel engine 1 are collected. In this embodiment, a porous ceramic material (cordierite) is used as the filter 5. Further, an electric heater (heat wire) 6 as a regenerating means is provided at the upstream end of the filter 5, and when the electric heater 6 is energized, the electric heater 6 generates heat and particulates collected by the filter 5 are generated. Is ignited.

A secondary air supply pipe 7 is branched on the upstream side of the housing 4 in the exhaust pipe 2, and an electromagnetic valve 8 is arranged in the middle of the secondary air supply pipe 7. The electromagnetic valve 8 is for preventing exhaust gas from flowing back to the secondary air supply path during normal operation. A discharge side of an electric air pump 9 as a regenerating means is connected to the tip of the secondary air supply pipe 7. An air cleaner 10 is provided on the intake side of the electric air pump 9. The air pump 9 is equipped with an electric motor, and the air pump 9 is driven by supplying electric power to the electric motor. Then, when the electromagnetic valve 8 is open, the secondary air is sucked into the secondary air supply pipe 7 through the air cleaner 10 by driving the electric air pump 9 to exhaust the exhaust pipe 2 of the diesel engine 1.
It will be supplied inside. As a result, the particulates collected by the filter 5 burn and the filter is regenerated.

An electric heater 6 is connected to the power source 11 to form a power source circuit. A bipolar transistor 12 is arranged in the middle of the power supply line. Then, by controlling the ON / OFF of the bipolar transistor 12, the energization of the electric heater 6 can be controlled.

An electric air pump 9 is connected to the power source 11 to form a power circuit. A bipolar transistor 13 is arranged in the middle of the power supply line. By controlling the on / off of the bipolar transistor 13, the electric motor of the electric air pump 9 can be drive-controlled.

A pressure sensor 14 is provided in the exhaust pipe 2 on the upstream side of the filter 5, and the pressure sensor 14 guides the pressure of the exhaust gas on the upstream side of the filter 5 by the pressure guiding pipe 14a to detect the pressure. A pressure sensor 15 is provided in the exhaust pipe 2 on the downstream side of the filter 5, and the pressure sensor 15
Guides the pressure of the exhaust gas on the downstream side of the filter 5 through the pressure guiding pipe 15a and detects the pressure.

A temperature sensor 16 is provided at the upstream end of the filter 5 so that the internal temperature of the filter 5 can be detected. The temperature sensor 16 can detect the internal temperature of the filter at the initial stage of regeneration. That is, the electric heater 6 ignites from the upstream side of the filter 5 and the filter 5
It is possible to measure the filter temperature at the start of combustion when the fuel is burned to the downstream side.

An exhaust gas temperature sensor 17 as an operating condition detecting means is attached to the exhaust pipe 2, and the sensor 17 detects the exhaust gas temperature. Further, the diesel engine 1 is provided with an engine speed sensor 18 as an operating condition detecting means.

An electronic control unit (hereinafter referred to as an ECU) 19 as a comparative collection amount calculation means, a determination means, a reproduction control means, and a correction means is mainly composed of a CPU and various memories. The ECU 19 is connected to the base terminal of the bipolar transistor 12, and the ECU 19 controls ON / OFF of the bipolar transistor 12. Also, ECU
19 is connected to the base terminal of the bipolar transistor 13, and the ECU 19 controls ON / OFF of the bipolar transistor 13.

Pressure sensors 14 and 15 are connected to the ECU 19, and the ECU 19 inputs signals from the pressure sensors 14 and 15 to detect the upstream pressure and the downstream pressure of the filter 5. Further, a temperature sensor 16, an exhaust gas temperature sensor 17, and an engine speed sensor 18 are connected to the ECU 19, and the ECU 19 connects these sensors 16, 17, 18 to each other.
A signal from is input to detect the temperature of the filter 5, the exhaust gas temperature, and the engine speed.

Further, the ECU 19 is connected to the electromagnetic valve 8 and controls the opening / closing of the electromagnetic valve 8. Further, the ECU 19 uses the particulate collection amount Pmq1 or Pm described later.
When q2 becomes a predetermined value or more, the bipolar transistors 12 and 13 and the electromagnetic valve 8 are controlled to burn the particulates collected in the filter 5 and regenerate the filter 5.

An alarm lamp 20 as an alarm means is connected to the ECU 19. The alarm lamp 20 is arranged on the instrument panel of the vehicle. Next, the operation of the diesel engine exhaust gas purification device thus configured will be described.

The ECU 19 obtains the pressure difference ΔP (= P1−P2) between the filter upstream pressure P1 by the pressure sensor 14 and the filter downstream pressure P2 by the pressure sensor 15, that is, the ventilation resistance of the filter 5, and this pressure difference ΔP. Then, the particulate collection amount Pmq1 is calculated by the following equation. here,
The particulate collection amount Pmq1 is defined by the particulate collection weight per unit volume of the filter 5.

Pmq1 = K1 (Q _st / Q _a ) ΔP where K1 is a coefficient for converting the differential pressure into the trapped amount, Q
_st exhaust gas amount in the standard engine operating conditions, Q _a is the actual amount of exhaust gas, in the present embodiment (the diesel engine cylinder volume / 2) · {exhaust gas temperature / (273Tasu
20)} · (engine speed) to calculate Q _a .

The ECU 19 executes a process for obtaining the particulate collection amount Pmq2 from the engine operating condition shown in FIG. 2 every predetermined time. Here, the particulate collection amount Pmq2 is defined by the particulate collection weight per unit volume of the filter 5.

In step 101, the ECU 19 reads the correction coefficient a _{n according} to the filter temperature at the time of regeneration. The initial value of the correction coefficient a _n is "1". A method for _obtaining the correction coefficient a _n will be described later.

Then, in step 102, the ECU 19 obtains the particulate emission rate k ₂ determined by the engine operating conditions. This particulate emission rate k ₂ is
It refers to the particulate discharge weight per unit time, and more specifically, the particulate discharge weight is the filter 5
It is defined by the particulate discharge weight per unit volume of. This particulate emission rate k ₂ is generally determined by the engine operating conditions, and the particulate emission rate k ₂ should be integrated using the map of the particulate emission rate k ₂ measured in advance on the target engine (Fig. 4). Thus, the particulate collection amount Pmq2 can be obtained. That is, the particulate emission rate k ₂
Is determined by the engine speed and the engine load, the engine speed is detected by the engine speed sensor 18, and the engine load is detected by the exhaust gas temperature sensor 17. Here, instead of the exhaust gas temperature by the exhaust gas temperature sensor 17, the detection element corresponding to the engine load may be the accelerator opening degree by the accelerator opening degree sensor or the rack position by the rack position sensor in the row fuel injection pump.

The map of the particulate emission rate k ₂ shown in FIG. 4 is obtained by previously obtaining the particulate emission rate k ₂ according to the engine speed and the exhaust gas temperature.
The ECU 19 uses the k ₂ map to determine the particulate emission rate k ₂ from the engine speed and exhaust gas temperature at that time.
Ask for.

The ECU 19 determines in step 103 the correction coefficient a.
Multiply _n by the particulate discharge rate k ₂ . further,
ECU19 updates the particulate collection amount Pmq2 by adding the correction coefficient a _n and multiplication value with particulate emission rates _{k 2 (= a n · k} 2) in the previous particulate collection amount Pmq2 at step 104 . By repeating such processing, the particulate discharge rate k ₂ is integrated to calculate the particulate collection amount Pmq2.

FIG. 3 shows a learning process of the correction coefficient a _n performed every time the reproduction is completed. That is, by collecting the particulate emission rate k ₂ , the particulate collection amount P
When mq2 is obtained, there is a variation for each engine and each fuel injection pump, and it is not possible to follow the changes over time, environmental changes (intake temperature, humidity), etc. Such a decrease in detection accuracy hinders stable regeneration, and there is a possibility that the filter 5 may be melted and unburned. Therefore, the maximum temperature T of the upstream portion of the filter at the initial stage of regeneration
_Since the relationship between _MAX and the amount of particulate collection is as shown in FIG. 5, the maximum temperature T of the upstream portion of the filter at the initial stage of regeneration is
Correct with _MAX .

Each time the filter 5 is regenerated, the ECU 19 uses the temperature sensor 16 to determine the filter maximum temperature T _MAX during the regeneration period. And the ECU
In step 201, when the maximum temperature T _MAX at the upstream end in the filter 5 in the initial stage of regeneration exceeds 900 ° C. in step 201, the correction coefficient a _n is learned and corrected to a large value of “0.01” in step 202. As a result, the particulate collection amount Pmq2 at the next collection is corrected to a larger value. for that reason,
The actual amount of traps at the start of regeneration is lowered and the regeneration temperature is lowered.
Further, the ECU 19 determines in steps 201 and 203 that the maximum temperature T _MAX at the upstream end in the filter 5 at the initial stage of regeneration is 800.
If the temperature does not exceed ℃, in step 204 the correction coefficient a
Learning correction is performed on _n to a small value of "0.01". as a result,
The particulate collection amount Pmq2 at the next collection is corrected to a smaller value. Therefore, the amount of trapped material at the start of regeneration increases and the regeneration temperature rises.

The determination operation (the abnormality detection operation of the Pmq1 value) in the ECU 19 will be described with reference to the flowchart of FIG. The process of FIG. 6 is a routine that is executed every predetermined time.

In step 301, the ECU 19 determines that the particulate collection amount Pmq1 is 0.7 Pmq2 and 1.3 Pmq2.
Whether it is between 2 and 0.7 (0.7Pmq2 <Pmq
1 <1.3 Pmq2) is determined. Then, the ECU 19
Is 0.7Pmq2 <Pmq1 <1.3Pmq2, it is determined that the pressure sensor 14 and the pressure sensor 15 are normal, and in step 302, the particulate collection amount P
mq1 is validated, and this value is used to determine whether or not the filter 5 is to be regenerated. Further, the ECU 19 executes step 3
At 03, the alarm lamp 20 is turned off.

On the other hand, if the ECU 19 does not satisfy 0.7Pmq2 <Pmq1 <1.3Pmq2 in step 301, the pressure guide pipes 14a, 1 of the pressure sensors 14, 15 are determined.
5a is clogged, etc., and particulate collection amount Pm
Assuming that q1 cannot be correctly calculated, the particulate collection amount Pmq2 is validated in step 304, and this value is used for determining whether or not the filter 5 is to be regenerated. Further, the ECU 19 turns on the alarm lamp 20 in step 305 to notify the driver of the failure of the pressure sensor.

The operation of the ECU 19 during reproduction will be described with reference to the flowchart of FIG. The process of FIG. 7 is a routine executed at a predetermined time (for example, every second).
First, while the diesel engine 1 is operating, the ECU
In step 400, it is determined whether it is the reproduction time. That is, the particulate collection amount Pmq1 or Pmq2
When it is determined that is less than the predetermined value and the reproduction is not necessary, this routine is ended. On the other hand, when the particulate collection amount Pmq1 or Pmq2 becomes equal to or larger than the predetermined value and the regeneration is required, the regeneration is started.

When the regeneration is started when the diesel engine 1 is stopped, the ECU 19 opens the electromagnetic valve 8 in step 500 so that air (oxygen) can be supplied from the electric air pump 9. Further, the ECU 19
In step 600, the bipolar transistor 12 is turned on to drive (energize) the electric heater 6. Also, the ECU 1
In step 700, 9 controls the bipolar transistor 13 to drive the electric air pump 9 to supply secondary air. That is, by energizing the electric heater 6, the particulates collected in the filter 5 are ignited,
The electric air pump 9 is driven to incinerate the particulates collected by the filter 5 to regenerate the filter.

Details of the control of the air pump 9 in step 700 of FIG. 7 will be described. When performing regeneration using the particulate collection amount Pmq1, step 7 in FIG.
At 00, the air pump 9 is continuously driven for a predetermined time. Further, when the reproduction is performed using the particulate collection amount Pmq2, the processing of FIG. 8 is executed.

The processing of FIG. 8 will be described with reference to the time chart of FIG. In the regeneration process, the correction coefficient a _n is not completely corrected at the beginning of the system startup, and the detection accuracy is not high in the method of obtaining the particulate trapped amount Pmq2 from the engine operating state. The playback temperature may deviate from the expected value. Therefore, the filter regeneration temperature is controlled within a predetermined range by detecting the filter temperature at the initial stage of regeneration and adjusting the secondary air flow rate so as to reach a predetermined temperature.

The ECU 19 determines in step 701 whether the filter temperature T _f measured by the temperature sensor 16 has reached 900 ° C. If it has not reached 900 ° C., the air pump 9 is turned on in step 702. By repeating steps 701 and 702, the temperature of the filter 5 rises (see FIG. 9).
Before t1).

When the filter temperature T _f reaches 900 ° C. (timing of t1 in FIG. 9), the ECU 19 shifts from step 701 to step 703 and moves to the air pump 9
Is turned off and the off time TM1 of the air pump 9 is measured. Then, the ECU 19 determines in step 704 whether the filter temperature T _f has reached 800 ° C., and 800 ° C.
If not, the process returns to step 703. By repeating steps 703 and 704, the temperature of the filter 5 decreases and the off time TM1 of the air pump 9 is measured (t1 to t2 in FIG. 9).

After that, when the filter temperature T _f reaches 800 ° C. (timing t2 in FIG. 9), the ECU 19 shifts from step 704 to step 705 and the air pump 9
Is turned on and the on-time TM2 of the air pump 9 is measured. Then, the ECU 19 determines in step 706 whether or not the filter temperature T _f has reached 900 ° C., and 900
If the temperature is not ℃, the process returns to step 705. By repeating the steps 705 and 706, the temperature of the filter 5 rises and the ON time TM2 of the air pump 9 increases.
Is measured (t2 to t3 in FIG. 9).

When the filter temperature T _f reaches 900 ° C. (timing of t3 in FIG. 9), the ECU 19 proceeds from step 706 to step 707, and the air pump 9
Is turned off, and in step 708, step 7 is performed.
It is determined whether or not the off time TM1 measured in 03 has elapsed, and if it has not elapsed, the process returns to step 707. When the off time TM1 elapses due to the temperature of the filter 5 decreasing due to the repetition of steps 707 and 708 (timing t4 in FIG. 9), the ECU 19 shifts from step 708 to step 709 and turns on the air pump 9. Further, the ECU 19 executes step 710 in step 710.
It is determined whether or not the on-time TM2 measured in 05 has elapsed, and if not, the process returns to step 709. When the temperature of the filter 5 rises by repeating steps 709 and 710 and the ON time TM2 elapses (timing of t5 in FIG. 9), the ECU 19 shifts from step 710 to step 711. ECU 19 is step 71
In step 1, it is determined whether or not a predetermined time has elapsed since the secondary air control was started. If the predetermined time has not elapsed, step 70
Returning to step 7, the above-mentioned steps 707 to 711 are repeated.

The ECU 19 terminates the regeneration process when a predetermined time elapses after starting the secondary air control in step 711. As described above, in the present embodiment, the trapped amount Pmq1 of the particulates in the filter 5 is calculated from the pressure difference between the upstream side and the downstream side of the filter 5, and the particulates in the filter 5 is determined from the operating state of the diesel engine 1. The amount of collected particulate matter Pmq2 is calculated, and the amount of collected particulate matter Pmq1 and the amount of particulate matter collected Pmq
By comparing with q2, it is determined whether or not the amount of deviation between the two is within a predetermined range, and if it deviates from the predetermined range, it is determined that the collected amount Pmq1 of particulates from the pressure difference is abnormal. Then, in the event of an abnormality, the alarm lamp 20 is turned on to notify the driver, and the filter 5 is regenerated when the particulate collection amount Pmq2 exceeds a predetermined value. As a result, the abnormality of the particulate collection amount Pmq1 due to the clogging of the pressure guiding pipes 14a and 15a in the pressure sensors 14 and 15 is self-diagnosed by the particulate collection amount Pmq2 depending on the engine operating state, and an alarm is issued in case of abnormality. In addition to the above, the filter regeneration is surely performed with the particulate collection amount Pmq2 depending on the engine operating state, and the trouble due to the abnormality can be eliminated.

Further, the correction coefficient a _n is learned by the temperature inside the filter for each reproduction, and the amount of particulate collection Pmq is collected.
Since the value 2 is corrected, the measurement accuracy can be improved and the reliability can be improved.

The present invention is not limited to the above embodiment, but in the above embodiment, the amount of collected particulate matter Pmq2 from the operating state of the diesel engine and the amount of collected particulate matter Pmq1 from the pressure difference. When it is determined that there is an abnormality by comparing with, the filter is regenerated when the particulate collection amount Pmq2 becomes equal to or more than a predetermined value. However, either the alarm or the filter regeneration processing is performed. You may go to either one.

Further, although the alarm lamp 20 is used in this embodiment, the alarm may be given by a buser or the like. Further, in the present embodiment, the engine speed and the exhaust gas temperature (or the accelerator opening degree, the rack position of the row-type fuel injection pump) are used as the factors for obtaining the particulate collection amount Pmq2 from the engine operating state. A throttle opening sensor for detecting the throttle opening provided in the intake system of the diesel engine may be used, and the point is that it is possible to obtain the particulate collection amount from the engine operating state.

[0048]

As described above in detail, according to the invention described in claim 1, the excellent effect of being able to judge the erroneous detection of the particulate trapped amount is exhibited.

According to the invention of claim 2, claim 1
In addition to the effect of the invention described in (1), the reproduction process can be performed accurately. According to the invention described in claim 3, in addition to the effect of the invention described in claim 2, an alarm can be given to notify.

According to the invention of claim 4, claim 1
In addition to the effect of the invention described in (1), it is possible to more accurately determine the trapped amount of particulates.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an exhaust emission control device for a diesel engine of an embodiment.

FIG. 2 is a flowchart for explaining the operation.

FIG. 3 is a flowchart for explaining an operation.

FIG. 4 is a map for obtaining a particulate emission rate k ₂ .

FIG. 5 is a graph showing the relationship between the collection amount and the maximum temperature of the upstream portion of the filter at the start of regeneration.

FIG. 6 is a flowchart for explaining the operation.

FIG. 7 is a flowchart for explaining the operation.

FIG. 8 is a flowchart for explaining the operation.

FIG. 9 is a time chart for explaining the operation.

FIG. 10 is an overall configuration diagram of a conventional exhaust emission control device for a diesel engine.

[Explanation of symbols]

1 ... Diesel engine, 2 ... Exhaust pipe, 5 ... Filter,
6 ... Electric heater, 9 ... Air pump, 14 ... Pressure sensor,
15 ... Pressure sensor, 16 ... Temperature sensor, 17 ... Exhaust gas temperature sensor, 18 ... Engine speed sensor, 19 ... EC
U, 20 ... Alarm lamp

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location F02B 77/08 ZAB M (72) Inventor Takayuki Toya 1-chome, Showa-cho, Kariya city, Aichi prefecture Nippondenden Co., Ltd.

Claims (4)

[Claims] 1. A diesel engine exhaust system, comprising: a filter for collecting particulates; and a regeneration means for incinerating the particulates captured by the filter to regenerate the filter. The trapping amount of particulates in the filter is calculated from the pressure difference between the upstream side and the downstream side of the filter, and when the trapping amount of the particulates becomes a predetermined value or more, the regenerating means regenerates the filter. In the exhaust emission control device for a diesel engine, the operating state detection means for detecting the operating state of the diesel engine, and the amount of particulates collected by the filter is calculated from the operating state of the diesel engine by the operating state detection means. And a collection amount of particulates by the comparison collection amount calculating unit. , The amount of particulates collected from the pressure difference is compared to determine whether the amount of deviation between the two is within a predetermined range. If the amount of deviation is out of the predetermined range, the amount of particulates collected from the pressure difference is abnormal. An exhaust emission control device for a diesel engine, comprising: 2. When the determination means determines that there is an abnormality, and when the amount of particulates collected by the comparison amount collection means becomes equal to or more than a predetermined value, the regeneration means regenerates the filter. Claim 1 provided with a control means.
Exhaust gas purification device for diesel engine according to. 3. The exhaust emission control device for a diesel engine according to claim 1, further comprising alarm means for issuing an alarm when the determination means determines that there is an abnormality. 4. The exhaust gas purification device for a diesel engine according to claim 1, wherein the comparative trapping amount calculating means has a correcting means for correcting the trapping amount of particulates according to the temperature of the filter during regeneration.