JP6711252B2 - Poisoning treatment device - Google Patents

Description

The present invention relates to a poisoning treatment device that treats poisoning of a catalyst inlet end surface of an internal combustion engine of a vehicle.

Technology for highly accurately determining the abnormality of the particulate filter provided in the exhaust passage of an internal combustion engine, more specifically, when the temperature of the exhaust gas is decreased without reducing the flow rate of the exhaust gas flowing into the filter. There is known a technique for determining an abnormality of the filter based on a change in the temperature of the exhaust gas flowing out from the filter (for example, refer to Patent Document 1).

JP, 2010-112254, A

By the way, in the case of traveling in a traffic jam or traveling to a nearby place for a short time, the catalyst temperature of the catalyst for purifying the exhaust gas discharged from the combustion engine of the internal combustion engine is in the low temperature range of 250°C to 350°C. Will remain included. When the temperature of the catalyst becomes low as described above for a long time, poisoning (for example, HC (hydrocarbon) occurs at the catalyst inlet end surface where the exhaust gas flows into the catalyst. The catalytic reaction may be hindered, the exhaust gas value may be deteriorated, and the environment may be adversely affected.

Here, the HC poisoning is eliminated by executing a regeneration process of regenerating the diesel particulate filter. However, since this reproduction processing is executed in a fixed cycle, for example, in the case of traffic congestion as described above, traveling for a short time to a close place, or the like, the reproduction processing may not be executed. In such a case, the vehicle runs while the end face of the catalyst inlet is poisoned, and the exhaust gas value deteriorates and exceeds the regulation value.

Further, from the viewpoint of real drive emission, it is desirable to quickly remove the poisoning that causes the exhaust gas value to deteriorate.

The present invention has been made in view of the above circumstances, and when poisoning occurs at the catalyst inlet end surface into which gas discharged from an internal combustion engine flows, quickly performs poisoning removal processing at appropriate timing. Accordingly, it is an object of the present invention to provide a poisoning treatment device that can prevent deterioration of the exhaust gas value when the vehicle is running.

A poisoning treatment apparatus used in a vehicle equipped with an internal combustion engine of the present invention is a purification means for purifying gas discharged from the internal combustion engine, a gas temperature detection means for detecting the temperature of the gas, and the gas flowing in. When the temperature value detected by the gas temperature detection means is a predetermined low temperature or less, a reference value stored in the storage means is stored as a reference value stored in the storage means for storing a reference value for determining whether or not the purification means is poisoned. , A changing means for changing to a reference value that makes it easier to determine poisoning of the purifying means as the purifying means is used at a temperature lower than the predetermined low temperature, and the purifying means based on the changed reference value. Is provided with a determination means for determining whether or not poisoned, and a removal means for removing the poisoning when the determination means determines that the poisoning is performed, and the reference value is the purification means. temperature, characterized Rukoto be determined based on the accumulation time of below the predetermined low temperature.

According to the poisoning treatment apparatus configured as described above, when poisoning occurs on the catalyst inlet end surface into which the gas discharged from the internal combustion engine flows, it is possible to quickly perform the poisoning removal processing at appropriate timing. It is possible to prevent the exhaust gas value from deteriorating when the vehicle is running.

Further, the poisoning processing device includes a vehicle speed detection means for detecting the vehicle speed of the vehicle, the vehicle speed zone is divided into a plurality of vehicle speed zones, the reference value is provided for each of a plurality of vehicle speed zones, the determination means Alternatively, it may be determined whether or not the purifying unit is poisoned by using the changed reference value corresponding to the vehicle speed range including the vehicle speed detected by the vehicle speed detecting unit.

With this configuration, it is possible to use a changed reference value that is different according to each vehicle speed band, and it is possible to more accurately determine poisoning according to the traveling speed of the vehicle.

Further, the poisoning treatment device may further include a filter downstream of the purification means, and the removal means may recover the poisoning of the purification means by regenerating the filter.

According to the present invention, when poisoning occurs in the catalyst inlet end surface into which gas discharged from the internal combustion engine flows, by promptly performing the poisoning removal processing at an appropriate timing, the exhaust gas during traveling of the vehicle A poisoning treatment device capable of preventing the deterioration of the value can be provided.

FIG. 3 is a diagram showing an example of a schematic configuration of a fuel system and an exhaust system of an internal combustion engine provided in the vehicle according to the same embodiment. The figure which shows an example of the reference value for the poisoning determination which concerns on the same embodiment. The figure which shows an example of the deterioration change coefficient which concerns on the same embodiment. The figure which shows an example of the reference value changed from the reference value of FIG. The flowchart which shows an example of the process which changes the reference value for the poisoning determination which concerns on the same embodiment. The flowchart which shows an example of the poisoning process which concerns on the same embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing an example of a schematic configuration of a fuel system and an exhaust system of an engine 1 (internal combustion engine) provided in a vehicle 100 to which the poisoning treatment apparatus of the present invention is applied. Since the configuration of the fuel system and the exhaust system other than the schematic configuration is the same as that of the conventional vehicle, illustration and description thereof will be omitted.

The engine 1 is a multi-cylinder diesel engine equipped with a common rail 2. The cylinder head 3 of the engine 1 is provided with an electromagnetic in-cylinder fuel injection valve 5 facing each combustion chamber 4 for each cylinder. Each in-cylinder fuel injection valve 5 is connected to the common rail 2 by a high pressure pipe 6, and the common rail 2 is connected to a fuel pump 8 via a high pressure pipe 7. The fuel pump 8 is driven by the engine 1 and has a function of supplying the fuel stored in the fuel tank 9 to the common rail 2. The fuel supplied to the common rail 2 is stored in a high pressure state and is injected into the combustion chamber 4 from each in-cylinder fuel injection valve 5 when the engine 1 is operating.

On the other hand, the exhaust pipe 11 of the engine 1 is provided with an oxidation catalyst 12 (purification means), a NOx storage catalyst 13 (purification means), and a diesel particulate filter 14 in order from the upstream side. Here, the NOx storage catalyst 13 may have a function of an oxidation catalyst. The oxidation catalyst 12 is formed by supporting a catalytic noble metal such as platinum (Pt), palladium (Pd), and rhodium (Rh) on a porous wall forming a passage, and oxidizes CO and HC in exhaust gas. Has a function of converting into CO2 and H2O, and oxidizing NO in the exhaust gas to generate NO2.

The NOx storage catalyst 13 is constituted by, for example, a carrier containing a noble metal such as platinum (Pt) or palladium (Pd) and a NOx storage agent such as barium (Ba) or potassium (K) supported thereon. While trapping NOx in an air-fuel ratio atmosphere (oxidizing atmosphere), it has the function of releasing trapped NOx in a rich air-fuel ratio atmosphere (reducing atmosphere) and reacting with HC and CO in the exhaust gas to reduce it. doing.

The diesel particulate filter 14 has, for example, a function of trapping PM in exhaust gas by alternately closing upstream and downstream sides of the passage of the honeycomb carrier with plugs, and further forming a passage. It is formed by supporting a catalytic noble metal such as platinum (Pt), palladium (Pd), rhodium (Rh) on the porous wall.

An exhaust pipe internal fuel injection valve (exhaust passage internal fuel injection valve) 15 may be installed on the upstream side of the oxidation catalyst 12. The in-exhaust pipe fuel injection valve 15 is connected to the fuel pump 8 via a high-pressure pipe 16, and fuel is supplied from the fuel pump 8. The exhaust pipe fuel injection valve 15 has a function of injecting the supplied fuel from the injection port into the exhaust pipe 11.

The ECU 20 is a control device for performing comprehensive control including operation control of the engine 1, and includes an input/output device, a storage device (ROM, RAM, nonvolatile RAM, etc.), a central processing unit (CPU), and the like. It is composed of.

At the input side of the ECU 20, an inlet temperature detection sensor T1 for detecting the temperature of the catalyst inlet end surface into which the gas discharged from the engine 1 flows, a catalyst temperature detection sensor T2 for detecting the temperature of the NOx storage catalyst, and an exhaust gas temperature are provided. Various sensors such as an exhaust gas temperature detection sensor (temperature detection means) T3 and a vehicle speed detection sensor (vehicle speed detection means) T4 for detection are connected, and detection information from these sensors is input. The vehicle speed detection sensor T4 is disposed, for example, near an axle (not shown) of the vehicle 100, detects the rotation speed of the axle, and outputs the detected rotation speed to the ECU 20. The ECU 20 detects the vehicle speed of the vehicle 100 based on the input rotation speed of the axle.

On the other hand, on the output side of the ECU 20, various output devices such as an intake throttle valve (not shown) are connected in addition to the in-cylinder fuel injection valve 5 described above. The ECU 20 calculates the fuel injection amount, the fuel injection timing, etc. based on the detection information from the various sensors and outputs them to various output devices, so that the in-cylinder fuel injection valve 5 and the intake throttle valve etc. can be output at appropriate timings. Control the output device of.

By arranging the oxidation catalyst 12 upstream of the diesel particulate filter 14 as described above, NO2 is discharged from the oxidation catalyst 12 during normal operation, that is, in a lean air-fuel ratio atmosphere, and the NOx storage catalyst 13 is discharged. It passes through and flows into the diesel particulate filter 14, and reacts with the soot, which is the carbon component in the PM collected and accumulated in the diesel particulate filter 14, to oxidize it. The oxidized soot becomes CO2 and is removed from the diesel particulate filter 14, and the diesel particulate filter 14 is continuously regenerated.

When the vehicle 100 configured as described above travels in a traffic jam or travels to a nearby place in a short time, the exhaust gas remains at a low temperature and does not reach a high temperature during the travel. Therefore, when the exhaust gas has a low temperature (for example, 300° C.), the HC poisoning occurs in the purifying means. On the other hand, the diesel particulate filter executes regeneration, for example, at a constant cycle. For this reason, in the present embodiment, the reference value described below is used to cause the diesel particulate filter to be regenerated when the reference value becomes equal to or less than the reference value while the vehicle 100 is traveling.

First, the reference value for determining whether or not the catalyst inlet end surface of the NOx storage catalyst 13 is poisoned will be described. Although the NOx storage catalyst 13 is referred to in the present embodiment, the same applies to the oxidation catalyst 12, of course. FIG. 2 is a diagram showing an example of the reference value. This reference value is stored in, for example, a storage device (storage means) included in the ECU 20.

In FIG. 2, the horizontal axis represents the integrated time t and the vertical axis represents the load. Here, the load is the temperature difference heat integrated amount (ΣΔT) calculated from the temperature difference between the catalyst inlet end surface detected by the inlet temperature detection sensor T1 and the catalyst temperature detected by the catalyst temperature detection sensor T2. Is.

Further, the high load, the medium load, and the low load correspond to the cases where the traveling speed of the vehicle 100 is the low vehicle speed, the medium vehicle speed, and the high vehicle speed, respectively. For the low vehicle speed, the medium vehicle speed, and the high vehicle speed, the predetermined vehicle speed zone is further divided into three vehicle speed zones of a low vehicle speed zone, a medium vehicle speed zone, and a high vehicle speed zone, and a reference value is set according to each vehicle speed zone. In the present embodiment, when the temperature detected by the exhaust gas temperature detection sensor T3 is high, it is unlikely that the catalyst inlet end surface will be poisoned, so that HC is likely to be adsorbed on the catalyst inlet end surface. Poisoning is determined at a low temperature (for example, 300° C.).

Further, the reference value Sa3 at a high vehicle speed at which the exhaust gas temperature is relatively high and is less likely to be subjected to HC poisoning prevents the erroneous determination of HC poisoning by increasing the load ΣΔT3 and shortening the integration time t3. ing. The reference value Sa1 at a low vehicle speed in which the temperature of the exhaust gas is relatively low and is susceptible to HC poisoning prevents the erroneous determination of HC poisoning by lowering the load ΣΔT1 and increasing the integration time t1. .. Regarding the reference value Sa2 positioned between the reference values Sa3 and Sa1, the load ΣΔt2 is an intermediate value between the loads ΣΔT3 and ΣΔT1, and the integration time t2 is an intermediate value between the integration time t3 and the integration time t1.

The reference value Sa3 is calculated from the integrated time t3 and the temperature difference heat integrated amount ΣΔT3, the reference value Sa2 is calculated from the integrated time t2 and the temperature difference heat integrated amount ΣΔT2, and the reference value Sa1 is calculated from the integrated time t1. And the temperature difference heat integrated amount ΣΔT1.

FIG. 3 is a diagram showing an example of the deterioration change coefficient k. The deterioration change coefficient k is the period when the catalyst is used after the reference values Sa1, Sa2, Sa3 described above are reduced to a predetermined low temperature or less when the vehicle 100 travels at a temperature of the exhaust gas lower than the predetermined low temperature. Is a coefficient for changing to a reference value that makes it easier to determine the poisoning of the end face of the catalyst inlet as becomes longer. In the present embodiment, the deterioration coefficient is set to gradually decrease from 1 according to the traveling distance D. In addition, although the case where the deterioration change coefficient k decreases linearly according to the travel distance D has been described in the present embodiment, the deterioration change coefficient k may decrease non-linearly. Further, although the deterioration change coefficient k has been described as being associated with the traveling distance D, it may be associated with the time when the catalyst is used in a low temperature environment.

Next, a case where the reference values Sa3, Sa2, Sa1 are changed using the deterioration change coefficient k will be described. FIG. 4 is a diagram showing an example of the reference values Sb3, Sb2, Sb1 changed by multiplying the reference values Sa3, Sa2, Sa1 described in FIG. 2 by the deterioration change coefficient k (<1).

As shown in FIG. 4, when the reference values Sb3, Sb2, Sb1 are compared with the reference values Sa3, Sa2, Sa1 referring to FIG. 2, respectively, the deterioration change coefficient k (<1) becomes the reference values Sa3, Sa2, Sa1. Since they are respectively multiplied, the slopes are gentle. Further, since the reference values Sa3 and Sb3 are respectively determined from the integration time t3 and the temperature difference heat integration amount ΣΔT3, the reference value Sb3 has a gentle slope, and thus the relationship of the reference value Sb3<reference value Sa3 is established. Such a relationship is similarly established even if other reference values Sb2<reference value Sa2 and reference value Sb1<reference value Sa1. In this way, the changed reference values Sb3, Sb2, Sb1 become smaller than the original reference values Sa3, Sa2, Sa1 based on the deterioration change coefficient k (that is, the traveling distance D), so that the catalyst inlet end surface is It becomes easier to determine whether poisoning has occurred. In other words, the criteria for HC poisoning become stricter, and poisoning can be promptly judged at appropriate timing.

Next, the process of determining the poisoning generated at the catalyst inlet end face will be described with reference to FIGS. 5 and 6.
First, a process of changing the reference value for determining poisoning according to the traveling distance D will be described. FIG. 5 is a flowchart showing an example of a process executed by the ECU 20 to change the discussion reference value.

As shown in FIG. 5, the ECU 20 determines whether the temperature of the exhaust gas is equal to or lower than a predetermined low temperature (ST101). More specifically, the ECU 20 determines whether or not the temperature input from the exhaust gas temperature detection sensor T3 is equal to or lower than a predetermined low temperature (300° C. in the present embodiment). If it is determined that the temperature is not lower than the predetermined low temperature (ST101: NO), the process returns.

When it is determined that the temperature is equal to or lower than the predetermined low temperature (ST101: YES), the ECU 20 measures the traveling distance D. That is, the distance traveled by the vehicle 100 from when the temperature becomes equal to or lower than the predetermined low temperature is measured. The travel distance D is measured, for example, based on the rotation speed of the axle input from the vehicle speed detection sensor T4.

Next, the ECU 20 changes the reference values Sa3, Sa2, Sa1 to the reference values Sb3, Sb2, Sb1 according to the traveling distance D measured in step ST102 (ST103: changing means). As described above, the reference values Sa3, Sa2, Sa1 are changed to the reference values Sb3, Sb2, Sb1 using the deterioration change coefficient k according to the traveling distance D so that poisoning can be more easily determined.

Next, the ECU 20 determines whether the poisoning process is a return (ST104). Whether or not the poisoning process is a return is determined based on whether or not the process is a return in the process of FIG. 6 described later. When it is determined that the poisoning process is not the return (ST104: NO), the process returns to step ST102. That is, the travel distance D is measured (ST102) and the reference value is changed according to the travel distance D (ST103) until the poisoning process is determined to be a return process.

On the other hand, when it is determined that the poisoning process is a return (ST104: YES), the ECU 20 clears the measured traveling distance D (ST105). The case where the poisoning process is returned will be described later with reference to FIG. Then, this process is a return.

Next, a process for determining and removing HC poisoning will be described. FIG. 6 is a flowchart showing an example of the poisoning removal processing executed by the ECU 20. Note that the following processing is always executed while the vehicle 100 is traveling.

As shown in FIG. 6, the ECU 20 determines whether the temperature of the exhaust gas is lower than a predetermined low temperature (ST201). Here, the predetermined low temperature is, for example, 300° C. as described above. The temperature of the exhaust gas is acquired from the exhaust temperature detection sensor T3. When it is determined that the temperature is not lower than the predetermined low temperature, that is, the temperature is equal to or higher than the predetermined low temperature (ST201: NO), this process returns.

When it is determined that the temperature is lower than the predetermined low temperature (ST201: YES), the ECU 20 determines whether the vehicle speed of the vehicle 100 is a low vehicle speed (ST202). More specifically, the ECU 20 measures the vehicle speed of the vehicle 100 based on the rotation speed of an axle (not shown) input from the vehicle speed detection sensor T4, and the measured vehicle speed is included in the low vehicle speed range. It is determined whether or not (ST202).

When it is determined that the vehicle speed is low (ST202: YES), the ECU 20 measures the integration time t3 and the temperature difference heat integration amount ΣΔT3 which is the integration amount of the temperature difference ΔT3 with respect to the integration time t3 (ST203). The temperature difference ΔT3 is obtained from the temperature input from the first temperature detection sensor T1 and the temperature input from the second temperature detection sensor T2.

Next, the ECU 20 acquires the changed reference value Sb3 corresponding to the low vehicle speed (ST204). More specifically, the deterioration variable coefficient k is multiplied according to the traveling distance D of the vehicle 100 after the temperature becomes a predetermined low temperature, so that the reference value Sa3 is changed to the changed reference value Sb3 (see FIGS. 2 to 4). ) To get.

Next, the ECU 20 compares the value Sb obtained by multiplying the temperature difference heat integration amount ΣΔT3 and the integration time t3 measured in step ST203 and dividing by 2 with the changed reference value Sb3 obtained in step ST204 to determine the temperature. It is determined whether or not the differential heat integration amount ΣΔT3 is less than or equal to the changed reference value Sb3 (ST205: determination means).

When it is determined that the temperature difference heat integrated amount ΣΔT3 is not less than or equal to the changed reference value Sb3 (ST205: NO), the ECU 20 again determines whether the vehicle speed of the vehicle 100 is a low vehicle speed (ST206). When it is determined that the vehicle speed is low (ST206: YES), the process returns to step ST203. Accordingly, while the traveling speed of the vehicle 100 is maintained at a low vehicle speed, the value Sb obtained by multiplying the temperature difference heat integration amount ΣΔT3 and the integration time t3 and dividing by 2 is changed according to the traveling distance D. It is compared with the reference value Sb3 at any time. When it is determined that the traveling speed of the vehicle 100 is not the low vehicle speed (ST206: NO), the process returns, and the traveling distance D is cleared (see step ST105 in FIG. 5).

Further, when it is determined that the value Sb obtained by multiplying the temperature difference heat integration amount ΣΔT3 and the integration time t3 and dividing by 2 is less than or equal to the changed reference value Sb3 (ST205: YES), the ECU 20 performs the HC purge. (ST217: removing means). Here, the HC purge is a regeneration process of the diesel particulate filter 14. In the HC purge, for example, the diesel particulate filter 14 is operated at a catalyst temperature of 350° C. or higher for 10 minutes or longer. As a result, the HC poisoning state of the catalyst inlet end surface is eliminated, and the HC poisoning is removed.

On the other hand, when it is determined in step ST202 that the vehicle speed is not low (ST202: NO), the ECU 20 determines whether the vehicle speed of the vehicle 100 is the medium vehicle speed (ST207). When it is determined that the vehicle speed is medium (ST207: YES), the ECU 20 executes the same processing as the processing (ST203 to ST206) when it is determined that the vehicle speed is low.

That is, the ECU 20 measures the integrated time t2 and the integrated temperature difference heat amount ΣΔT2 (ST208), obtains the changed reference value Sb2 corresponding to the middle vehicle speed (ST209), and calculates the integrated temperature difference heat amount ΣΔT2 and the integrated time t2. It is determined whether or not the value Sb obtained from is less than or equal to the changed reference value Sb2 (ST210: determination means). Here, when it is determined that the value Sb is not less than or equal to the changed reference value Sb2 (ST210: NO), the process returns to step ST208. When it is determined that the value Sb is less than or equal to the changed reference value Sb2 (ST210: YES), the ECU 20 carries out the HC purge (ST217: removing means). As a result, the HC poisoning state of the catalyst inlet end surface is eliminated, and the HC poisoning is removed.

When it is determined in step ST207 that the vehicle speed is not the middle vehicle speed (ST207: NO), the ECU 20 determines whether the vehicle speed of the vehicle 100 is a high vehicle speed (ST212). When it is determined that the vehicle speed is high (ST207: YES), the ECU 20 performs the same process as the process (ST203 to ST206) when it is determined that the vehicle speed is low.

That is, the ECU 20 measures the integrated time t1 and the integrated temperature difference heat amount ΣΔT1 (ST213), acquires the changed reference value Sb1 corresponding to the high vehicle speed (ST214), and calculates the integrated temperature difference heat amount ΣΔT1 and the integrated time t1. It is determined whether or not the value Sb obtained by multiplying by and dividing by 2 is less than or equal to the changed reference value Sb1 (ST215: determination means). Here, when it is determined that the value Sb is not less than or equal to the changed reference value Sb1 (ST215: NO), the process returns to step ST213. When it is determined that the value Sb is less than or equal to the changed reference value Sb1 (ST215: YES), the ECU 20 carries out the HC purge (ST217: removing means). As a result, the HC poisoning state of the catalyst inlet end surface is eliminated, and the HC poisoning is removed. If it is determined in step ST212 that the vehicle speed is not high (ST212: NO), the process is returned in this embodiment.

In the vehicle 100 configured as described above, when the temperature detected by the exhaust gas temperature detection sensor T3 is equal to or lower than the predetermined low temperature, the ECU 20 increases the traveling distance D (the longer the NOx storage catalyst 13 is used). ), the reference value (Sb3, Sa2, Sa1) is changed to a reference value (Sb3, Sb2, Sb1) that makes it easier to determine poisoning of the NOx storage catalyst 13 by multiplying the deterioration change coefficient k, and the changed reference value Based on the above, it is determined whether or not the catalyst inlet end surface of the NOx storage catalyst 13 is poisoned by HC, and when it is determined that the catalyst is poisoned, HC purge is executed to remove the HC poisoning.

For this reason, the ECU 20 can quickly perform the poisoning removal processing at an appropriate timing when HC poisoning occurs on the catalyst inlet end surface into which the exhaust gas discharged from the engine 1 flows, and the vehicle 100 of the vehicle 100 can be removed. It is possible to prevent the exhaust gas value from deteriorating during traveling.

Further, the vehicle speed range of the traveling speed of the vehicle 100 when the temperature of the exhaust gas becomes equal to or lower than a predetermined low temperature is divided into a plurality of vehicle speed zones (low vehicle speed zone, medium vehicle speed zone, high vehicle speed zone), and HC poisoning determination is performed. The reference values Sa3, Sa2, Sa1 for are set for each of a plurality of vehicle speed zones (low vehicle speed zone, medium vehicle speed zone, high vehicle speed zone), and the ECU 20 is changed corresponding to the vehicle speed zone including the vehicle speed of the vehicle 100. Using the reference values (Sb3, Sb2, Sb1), it is determined whether the catalyst inlet end surface of the NOx storage catalyst 13 is poisoned with HC.

Therefore, the ECU 20 can use different reference values that are different depending on the vehicle speed zones of the low vehicle speed zone, the medium vehicle speed zone, and the high vehicle speed zone, and the determination of HC poisoning according to the traveling speed of the vehicle 100 can be performed. Can be executed more accurately.

In the above embodiment, the case where HC poisoning occurs as the poisoning of the catalyst inlet end surface has been described as an example, but the present invention is not limited to this. For example, the present invention can be applied to the case where S (sulfur) poisoning occurs on the catalyst inlet end surface as another catalyst inlet end surface. Furthermore, in the above-described embodiment, the case has been described in which it is determined whether or not HC poisoning has occurred on the catalyst inlet end surface of the NOx storage catalyst 13, but whether or not poisoning has occurred on the catalyst inlet end surface of another catalyst. The present invention can also be applied when determining whether or not.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements within a range not departing from the gist of the invention in an implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some constituent elements may be deleted from all the constituent elements shown in the above-described embodiment. Furthermore, the configurations of different embodiments may be combined.

DESCRIPTION OF SYMBOLS 1... Engine, 2... Common rail, 11... Exhaust pipe, 12... Oxidation catalyst, 13... NOx storage catalyst, 14... Diesel particulate filter, 20... ECU, 100... Vehicle, T1... 1st temperature detection sensor, T2 ... second temperature detection sensor, T3 ... exhaust gas temperature detection sensor, T4 ... vehicle speed detection sensor, Sa3, Sa2, Sa1 ... reference value, Sb1, Sb2, Sb3 ... changed reference value, k ... deterioration change coefficient, t1, t2, t3... Accumulated time

Claims (3)

The poisoning treatment device used in a vehicle equipped with an internal combustion engine is
Purifying means for purifying gas discharged from the internal combustion engine,
Gas temperature detecting means for detecting the temperature of the gas,
Storage means for storing a reference value for determining whether or not the purification means into which the gas flows is poisoned;
When the temperature detected by the gas temperature detecting means is lower than or equal to a predetermined low temperature, the reference value stored in the storage means is a poisoning of the purifying means as the use of the purifying means at the predetermined low temperature or lower becomes longer. Change means to change to a reference value that makes it easier to judge,
Based on the changed reference value, determination means for determining whether the purification means is poisoned,
When it is determined that the poisoning by the determination means, a removal means for removing the poisoning,
Equipped with
The reference value is determined based on the temperature of the purifying unit and an integrated time at the predetermined low temperature or lower,
A poisoning treatment device characterized by the above. Vehicle speed detecting means for detecting the vehicle speed of the vehicle,
Equipped with
The vehicle speed zone is divided into a plurality of vehicle speed zones,
The reference value is provided for each of a plurality of vehicle speed zones,
The determining means determines whether or not the purifying means is poisoned by using the changed reference value corresponding to a vehicle speed range including a vehicle speed detected by the vehicle speed detecting means,
The poisoning treatment device according to claim 1 , wherein the poisoning treatment device is a poisoning treatment device. Further having a filter downstream of the purification means,
The removing means recovers the poisoning of the purifying means by regenerating the filter.
The poisoning treatment device according to claim 1 or 2 , characterized in that.

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