JP2008069648A - Regeneration control device of particulate filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain filter regeneration after determining the deterioration in a front stage catalyst. <P>SOLUTION: This regeneration control device of a filter 21 has the front stage catalyst 20 and a particulate filter 21 carrying a catalyst capturing particulate matter in exhaust gas, in an exhaust passage 11, and regenerates the filter 21 by removing the particulate matter captured in the filter 21 by reacting HC supplied by post-injection by the front stage catalyst 20, and has a control means 26 for raising the temperature of the exhaust gas exhausted from an internal combustion engine 1, by reducing a post-injection quantity, when determining the deterioration in the front stage catalyst 20, by determining a deterioration state of the front stage catalyst 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a particulate filter regeneration control device including a pre-stage catalyst such as an oxidation catalyst.

  Conventionally, in order to remove particulate matter (hereinafter referred to as “PM”) typified by soot, which is particulate matter contained in the exhaust of a diesel engine, a pre-stage catalyst such as an oxidation catalyst and its A particulate filter (hereinafter simply referred to as “filter” or “DPF”) that captures PM is provided downstream, and the exhaust gas temperature is raised to, for example, 600 ° C. or higher by the supplied HC using the upstream catalyst. There is known a particulate filter regeneration control device for regenerating a filter by burning and removing PM deposited on the filter (see Patent Document 1).

This is because the temperature difference before and after the filter is monitored and it is determined that the degree of deterioration of the pre-catalyst increases as the temperature difference increases, and the concentration of supplied HC is lowered to prevent HC outflow and filter clogging. I am doing so.
JP 2004-353606 A

  However, in the above conventional example, after the deterioration of the pre-stage catalyst is determined, the supply concentration of HC is reduced to prevent HC from flowing downstream without reacting in the pre-stage catalyst. The exhaust gas temperature sufficient to regenerate the filter could not be obtained, and there was a possibility that filter clogging or over deposition would eventually be caused.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a particulate filter regeneration control device capable of continuing filter regeneration after determination of deterioration of the pre-stage catalyst.

  The present invention provides a pre-stage catalyst that is provided in an exhaust passage of an internal combustion engine and has an oxidizing ability, a particulate filter that is provided downstream of the pre-stage catalyst and carries a catalyst that captures particulate matter in the exhaust, and the pre-stage catalyst. An HC supply means for supplying HC from the upstream, and reacts the HC supplied by the HC supply means with a pre-catalyst to remove particulate matter captured by the particulate filter and regenerate the filter. A regeneration control device for a curate filter, wherein when the deterioration state of the preceding catalyst is determined by the deterioration state determining means for determining the deterioration state of the preceding catalyst, the amount of HC supplied by the HC supplying means is reduced. And a control means for raising the temperature of the exhaust gas discharged from the internal combustion engine.

  Therefore, in the present invention, when it is determined that the pre-stage catalyst having the oxidation capability provided in the exhaust passage is deteriorated, the amount of HC supplied by the HC supply means is reduced during regeneration of the particulate filter provided downstream of the pre-stage catalyst. By reducing the amount of exhaust gas and increasing the temperature of the exhaust gas discharged from the internal combustion engine, the regeneration of the particulate filter can be continued even after the deterioration of the pre-stage catalyst, ensuring the reliability of the particulate filter system and exhaust The performance can be maintained.

  The particulate filter regeneration control device of the present invention will be described below based on each embodiment.

(First embodiment)
FIG. 1 is a system configuration diagram of a supercharged diesel engine showing a first embodiment of a particulate filter regeneration control device to which the present invention is applied.

  As shown in FIG. 1, the engine body 1 is provided with a common rail fuel injection system including a common rail 2, a fuel injection valve 3, and a supply pump 4, and supplies high-pressure fuel to the engine body 1. The fuel injection valve 3 directly injects fuel into the combustion chamber 5 and can perform pilot injection before main injection, and variably controls the fuel injection pressure by changing the set fuel pressure in the common rail 2. it can.

  An exhaust turbine 10 </ b> A of the supercharger 10 is disposed in the exhaust passage 11 and rotates by exhaust from the engine body 1 to drive the compressor 10 </ b> B of the supercharger 10 disposed in the intake passage 12. The compressor 10B of the supercharger 10 is driven by the exhaust turbine 10A to supply compressed air to the engine body 1. The turbocharger 10 of the present embodiment adopts a variable displacement type, and in the low speed range, the variable nozzle (vane) 10C provided on the side of the turbine 10A is narrowed to increase the turbine efficiency, and this variable in the high speed range. By increasing the turbine capacity by opening the nozzle 10C, a high supercharging effect is obtained in a wide operation region.

  In the intake passage 12, an air flow meter 13 and an air cleaner 14 are disposed on the upstream side of the compressor 10B of the supercharger 10, and an intercooler 15 and a throttle valve 16 are interposed on the downstream side, respectively. The throttle valve 16 is, for example, an electronic control type that can be changed in opening degree using a step motor, and controls the amount of intake air that is drawn into the engine body 1 in accordance with the opening degree.

  The exhaust passage 11 is provided with an EGR passage 6 branched from the engine body 1 and the exhaust turbine 10A and connected to the intake passage 12, and an EGR valve 7 is interposed in the EGR passage 6. The EGR valve 7 is, for example, an electronically controlled type using a step motor, and controls the amount of exhaust gas recirculated to the intake side according to the opening, that is, the EGR amount sucked into the engine body 1. . In the exhaust passage 11, a pre-stage catalyst 20 and a particulate filter (hereinafter referred to as “DPF” or simply “filter”) 21 are sequentially provided downstream of the exhaust turbine 10 </ b> A. The pre-stage catalyst 20 is composed of an oxidation catalyst (DOC) that oxidizes HC and CO in an active state, or a NOx catalyst. The DPF 21 collects PM (particulate matter) in the exhaust gas. The collected PM is combusted by regeneration control that raises the exhaust temperature.

  As sensors for detecting various states, the air flow meter 13 for detecting the intake air amount, a rotational speed sensor 17 for detecting the engine rotational speed, an accelerator opening sensor 18 for detecting the accelerator opening, and a water temperature sensor 19 for detecting the cooling water temperature. A rail pressure sensor (not shown) for detecting the fuel pressure (that is, fuel injection pressure) in the common rail 2 is provided. Further, temperature sensors 22 and 23 for detecting the exhaust gas temperature at the outlet of the preceding catalyst 20 and the outlet exhaust temperature of the DPF 21 are provided, and a differential pressure sensor 24 for detecting the pressure difference between the inlet and the outlet of the DPF 21 is provided. ing. An exhaust sensor 25 that detects the exhaust air-fuel ratio or the oxygen concentration is provided on the downstream side of the DPF 21 in the exhaust passage 11.

  A control unit 26 constituted by a microcomputer comprising a CPU and its peripheral devices controls the driving of the fuel injection valve 3 by setting the fuel injection amount and the injection timing based on detection signals from the various sensors. The opening control of the throttle valve 16 and the EGR valve 7 is performed.

  The control unit 26 estimates the amount of PM accumulated in the DPF 21 based on a signal from the differential pressure sensor 24 that detects the pressure difference between the inlet and the outlet of the DPF 21, and a predetermined amount of PM is accumulated. If it is determined that the DPF 21 has been reproduced, the regeneration process of the DPF 21 is executed. In the regeneration process of the DPF 21, for example, hydrocarbon (HC), carbon monoxide (CO), etc. are supplied from the upstream side of the front catalyst 20, and at this time, exhaust gas whose temperature has been increased by heat generated in the front catalyst 20 is filtered. 21. As a method for supplying HC to the pre-stage catalyst 20, post injection in which fuel is injected again during the expansion stroke or exhaust stroke after the main injection from the fuel injection valve 3 in the engine body 1 can be exemplified. The fuel (HC) injected by the post injection is discharged from the combustion chamber 5 without being burned depending on the injection timing. The discharged HC is reformed by the high-temperature combustion gas by the main injection, and the front catalyst 20 It will be in the state which is easy to react with.

  Further, during regeneration of the DPF 21, the control unit 26, based on the exhaust gas temperature signal from the temperature sensor 22 disposed at the outlet of the front catalyst 20 and the post injection amount, The amount of HC passing through the catalyst 20 is estimated, and the deterioration state of the pre-stage catalyst 20 is determined. When the pre-catalyst 20 is deteriorated and the HC oxidizing ability is lowered, the HC reacting with the pre-catalyst 20 is decreased, the temperature rises slowly on the upstream side of the filter 21, and the PM oxidation at the DPF 21 becomes difficult. . Specifically, it is determined that the front catalyst 20 has deteriorated when the outlet exhaust gas temperature of the front catalyst 20 is not increased beyond the lower limit value of the set temperature increase rate set by a map or the like with respect to the post injection amount. Like to do. When the deterioration of the pre-stage catalyst 20 is determined, a warning is issued to the user, prompting the user to replace the pre-stage catalyst 20, and the amount of HC passing through the pre-stage catalyst 20 can be reacted by the DPF 21 (DPF allowable) The post-injection amount is decreased until (value) is reached (see FIG. 2A).

  The time chart shown in FIG. 3A shows the normal state (time point t0 to t1), the deterioration progress state (time point t1 to t2), and after the deterioration determination (time point t2 to t3) during regeneration of the DPF 21. 6 shows changes in the post-injection amount, the exhaust gas temperature after passing through the front catalyst 20, and the DPF 21 inlet HC concentration. When the pre-stage catalyst 20 starts to deteriorate (time points t1 to t), the exhaust gas temperature after passing through the pre-stage catalyst 20 begins to decrease and the DPF 21 inlet HC concentration starts to increase. When the exhaust gas temperature after passing through the front catalyst 20 is lowered until catalyst deterioration is determined (time t2), the post injection amount is increased until the amount of HC passing through the front catalyst 20 reaches the DPF 21 allowable value as described above. As a result, the DFC 21 inlet HC concentration is maintained at a predetermined concentration.

  Further, the control unit 26 directly increases the temperature of the exhaust gas discharged from the engine body 1 from the stage when the deterioration of the front catalyst 20 is determined, thereby reducing the post injection amount and reducing the burden on the front catalyst 20. While maintaining the regeneration temperature of the DPF 21. As means for raising the temperature of the exhaust gas discharged from the engine body 1, after-injection (see FIG. 2B) between main injection and post-injection, retard of main injection, reduction of excess air ratio of exhaust gas, excess One or two of the vane opening increases on the turbine 10A side of the feeder 10 are selected and executed. As a temperature increase target value of the exhaust gas temperature, a temperature at which regeneration of the DPF 21 can be performed, for example, 600 ° C. is set. In this way, the regeneration of the DPF 21 is continued even when the front catalyst 20 has deteriorated.

  The time chart shown in FIG. 3B shows the passage of time of the exhaust gas temperature at each inlet of the pre-stage catalyst 20 and the DPF 21. After the determination that the pre-stage catalyst 20 has deteriorated (time t2), when the combustion end timing in the cylinder of the engine body 1 is delayed, the exhaust gas temperatures at the inlets of the pre-stage catalyst 20 and the DPF 21 are increased, and the DPF 21 Is continued by the raised exhaust gas temperature (see time t2-3).

  FIG. 4 is a flowchart of the reproduction control based on the first embodiment. This regeneration control flowchart is based on a case where it is determined that the pressure difference between the inlet and the outlet of the DPF 21 reaches a predetermined value based on a signal from the differential pressure sensor 24 and a predetermined amount of PM has accumulated. It is executed every predetermined time during the regeneration process of the DPF 21 to be executed. This regeneration process of the DPF 21 is based on the premise that post injection for injecting fuel again is executed during the expansion stroke after the main injection from the fuel injection valve 3 in the engine body 1.

  First, in step S1, the control unit 26 reads the pre-stage catalyst deterioration flag, the post injection amount, the exhaust gas temperature after the pre-stage catalyst 20, and the pressure difference before and after the DPF 21, and proceeds to step S2.

  In step S2, it is determined whether or not the pre-stage catalyst deterioration flag is 0. If the pre-stage catalyst deterioration flag is (F = 1), the process proceeds to step S5, which is a process after deterioration of the pre-stage catalyst 20, and the pre-stage catalyst deterioration flag is set. If the catalyst deterioration flag is (F = 0), it is determined that the deterioration of the pre-stage catalyst 20 has not reached the determination standard, and the process proceeds to step S3.

  In step S3, depending on whether or not the actual temperature increase rate after the pre-catalyst 20> the catalyst deterioration determination temperature, the amount of HC reacting in the pre-catalyst 20 and the pre-catalyst 20 are determined based on the exhaust gas temperature signal and the post injection amount. The amount of passing HC is estimated, and the deterioration state of the front catalyst 20 is determined. In this determination, if the actual temperature after the front catalyst 20 is lower than the deterioration determination temperature corresponding to the post-injection amount, the deterioration of the front catalyst 20 has progressed by a predetermined amount or more, and the process proceeds to step S4 and the front catalyst deterioration flag (F = 1) is set, and the process proceeds to step S5. When the actual temperature after the front catalyst 20 is sufficiently high and the deterioration of the front catalyst 20 has not progressed, the current processing step is terminated.

  In step S5, since the deterioration of the pre-stage catalyst 20 has progressed, the post-injection amount is reduced and the process proceeds to step S6.

  In step S6, it is determined whether or not the amount of HC passing through the pre-stage catalyst 20 is below the DPF allowable value. If not, the process returns to step S5 to decrease the post-injection amount. It is determined whether or not the amount of HC passing through the catalyst 20 is below the DPF allowable value. If it is determined that the amount of HC passing through the pre-stage catalyst 20 has fallen below the DPF allowable value by repeating this processing step, the process proceeds to step S7. In this way, by limiting the amount of HC supplied to the DPF 21, it is prevented from being damaged due to melting damage or the like even under conditions where the bed temperature of the DPF 21 during regeneration is maximized.

  In step S7, the combustion end timing in the combustion chamber 5 is delayed to increase the inlet exhaust temperature of the DPF 21 that decreases due to the decrease in the post-injection amount, thereby ensuring the necessary DPF regeneration temperature. The combustion end timing is delayed by executing after injection that injects fuel earlier than post-injection in the expansion stroke after main injection, or executing main injection retard that delays the main injection timing under heavy operating conditions Then, the exhaust temperature is raised. Either one may be selected or both may be performed. The after injection or the main injection retard can achieve in-cylinder combustion within the range of the expansion stroke when the crank angle is injected from the top dead center angle to an angle of 90 degrees in the expansion stroke. Desirably, the spray is made in the range of 50 to 60 ° C. from the top dead center.

  In step S8, it is determined whether or not the increase in the exhaust gas temperature that increases due to the delay in the combustion end timing in step S7 exceeds the regeneration target temperature in the DPF 21, and if not, the process returns to step S7, and step S7 The exhaust temperature is raised by executing the above, the exhaust temperature is determined again in step S8, the exhaust temperature raising operation in step S7 is executed until the regeneration target temperature in the DPF 21 is exceeded, and the regeneration target temperature in the DPF 21 is set. At this point, the current processing step is terminated.

  As described above, since the inlet exhaust temperature of the DPF 21 is maintained at the DPF regeneration target temperature even when the front catalyst 20 is deteriorated, the regeneration state similar to that when the front catalyst 20 is normal can be maintained. In addition, the amount of HC passing through the front catalyst 20 gradually increases according to the degree of deterioration of the front catalyst 20, but the change in the amount of passing HC is caused by the feedback of the exhaust temperature after passing through the front catalyst 20 to By adjusting the injection amount and the delay operation of the combustion end timing, the inlet exhaust temperature of the DPF 21 can be stably maintained at the DPF regeneration target temperature, and the regeneration state of the DPF 21 can be maintained.

  In the present embodiment, the following effects can be achieved.

  (A) a pre-stage catalyst 20 that is provided in the exhaust passage 11 of the internal combustion engine 1 and has an oxidizing ability; a particulate filter 21 that is provided downstream of the pre-stage catalyst 20 and carries a catalyst that captures particulate matter in the exhaust; Fuel injection means 2 to 4 as HC supply means for supplying HC from the upstream side of the upstream catalyst 20, and reacting the HC supplied by the HC supply means (2 to 4) with the upstream catalyst 20, A regeneration control device for the particulate filter 21 that removes the particulate matter captured by the particulate filter 21 and regenerates the filter 21, a deterioration state determination unit 26 that determines a deterioration state of the preceding catalyst 20, and When the deterioration of the pre-stage catalyst 20 is determined by the deterioration state determination means 26, the amount of HC supplied by the HC supply means (2-4) is reduced. To, and so comprises a control means 26 for raising the temperature of the exhaust gas discharged from the internal combustion engine 1, a. For this reason, the regeneration of the particulate filter 21 can be continued even after the deterioration of the pre-stage catalyst 20, and the reliability of the particulate filter system and the exhaust performance can be maintained.

  (A) When it is determined that the pre-catalyst 20 is deteriorated, the amount of HC contained in the exhaust gas by the post injection is reduced, and the after injection between the main injection and the post injection by the fuel injection valve 3; Alternatively, since the temperature of the exhaust gas is raised by delaying the end of combustion in the cylinder of the injected fuel due to the delay of the main injection, the output performance of the internal combustion engine is lowered even after the deterioration of the front catalyst 20. Therefore, the regeneration of the filter 21 can be continued.

(Second Embodiment)
FIG. 5 is a flowchart of regeneration control based on the second embodiment of the particulate filter regeneration control apparatus to which the present invention is applied. In the present embodiment, a configuration in which the excess air ratio of the exhaust gas is reduced as a means for raising the exhaust temperature is added to the first embodiment. In addition, the same code | symbol is attached | subjected to the same apparatus and components as 1st Embodiment, and the description is abbreviate | omitted or simplified.

  The particulate filter regeneration control apparatus of the present embodiment is also provided with the system configuration of the turbocharged diesel engine shown in FIG. 1, and the regeneration control executed by the control unit 26 every predetermined time is shown in the flowchart of FIG. This configuration is different from the first embodiment. Also in FIG. 5, this regeneration control flowchart is based on the signal from the differential pressure sensor 24, when the pressure difference between the inlet and the outlet of the DPF 21 reaches a predetermined value, and a predetermined amount of PM is set. It is executed every predetermined time during the regeneration process of the DPF 21 that is executed when it is determined that the particles have accumulated. This regeneration process of the DPF 21 is based on the premise that post injection for injecting fuel again is executed during the expansion stroke after the main injection from the fuel injection valve 3 in the engine body 1.

  And also in the process step performed by the control unit 26, the process from step S1 to S6 is performed similarly to the process in 1st Embodiment. In the present embodiment, the exhaust temperature increasing process in steps S7 and S8 in the first embodiment is replaced with the processes in steps S9 to S12. The differences will be described below.

  In step S9, the exhaust temperature from the engine body 1 is increased by reducing the excess air ratio λ of the inlet exhaust temperature of the DPF 21 that has decreased as the post-injection amount decreases, and the necessary DPF regeneration temperature is ensured. . The excess air ratio λ can be reduced by reducing the opening of the intake throttle valve 16 or the opening of an exhaust valve (not shown) provided in the exhaust passage 11, or the EGR valve 7 provided in the EGR passage 6. One of the operations for increasing the opening degree and increasing the EGR rate is performed alone or in combination. Since the intake throttle and exhaust throttle are devices that change the intake flow rate, either one is operated. When the excess air ratio λ is reduced, the exhaust temperature is raised.

  In step S10, it is determined whether or not the raised exhaust gas temperature exceeds the regeneration target temperature in the DPF 21, and if not, the process returns to step S9 to further reduce the excess air ratio λ and again in step S10. It is determined whether or not the raised exhaust temperature exceeds the regeneration target temperature in the DPF 21, and by repeating this processing step, the exhaust temperature is raised above the regeneration target temperature, and the process proceeds to step S11.

  In step S11, the pressure difference before and after the DPF 21 is compared with the pressure difference in the previous process to determine whether or not the regeneration speed of the DPF 21 has dropped below the target regeneration speed. If the current process step is finished and the process is lowered, the process proceeds to step S12, where the operation for raising the exhaust temperature by reducing the excess air ratio λ is interrupted and switched to another exhaust temperature raising means. That is, the exhaust temperature increase operation by reducing the excess air ratio λ increases the generation of soot in the exhaust gas and decreases the regeneration speed of the DPF 21, so that it is executed only when the target regeneration speed can be secured.

  As described above, since the inlet exhaust temperature of the DPF 21 is maintained at the DPF regeneration target temperature even when the front catalyst 20 is deteriorated, the regeneration state similar to that when the front catalyst 20 is normal can be maintained. Moreover, the amount of HC passing through the front catalyst 20 gradually increases according to the degree of deterioration of the front catalyst 20, but the change in the amount of passing HC is caused by the feedback of the exhaust gas temperature after passing through the front catalyst 20 to the air By adjusting the excess rate λ to be reduced, the inlet exhaust temperature of the DPF 21 can be stably maintained at the DPF regeneration target temperature, and the regeneration state of the DPF 21 can be maintained.

  In the present embodiment, in addition to the effect (a) in the first embodiment, the following effects can be achieved.

  (C) When the deterioration of the front catalyst 20 is determined, the supply amount of HC contained in the exhaust gas by the post injection is reduced, and the opening of the throttle valve 16 disposed in the intake passage 12 or the exhaust passage 11 Or by opening the EGR valve 7 provided in the EGR passage 6 to reduce the excess air ratio λ of the exhaust gas, thereby increasing the temperature of the exhaust gas. Thereafter, the regeneration of the filter 21 can be continued effectively in the region of the excess air ratio where the regeneration speed of the DPF 21 can be maintained.

(Third embodiment)
FIG. 6 is a flowchart of regeneration control based on the third embodiment of the particulate filter regeneration control device to which the present invention is applied. In this embodiment, the structure which adjusts the variable vane opening degree of a supercharger as a means for raising the exhaust gas temperature is added to the first embodiment. In addition, the same code | symbol is attached | subjected to the same apparatus and components as 1st Embodiment, and the description is abbreviate | omitted or simplified.

  The particulate filter regeneration control apparatus of the present embodiment is also provided with the system configuration of the turbocharged diesel engine shown in FIG. 1, and the regeneration control executed by the control unit 26 every predetermined time is a flowchart shown in FIG. This configuration is different from the first embodiment. Also in FIG. 6, this regeneration control flowchart is based on the signal from the differential pressure sensor 24, when the pressure difference between the inlet and the outlet of the DPF 21 reaches a predetermined value, and a predetermined amount of PM is set. It is executed every predetermined time during the regeneration process of the DPF 21 that is executed when it is determined that the particles have accumulated. This regeneration process of the DPF 21 is based on the premise that post injection for injecting fuel again is executed during the expansion stroke after the main injection from the fuel injection valve 3 in the engine body 1.

  And also in the process step performed by the control unit 26, the process of step S1-S6, S8 is performed similarly to the process in 1st Embodiment. In the present embodiment, the exhaust gas temperature increasing process in step S7 in the first embodiment is replaced with the process in step S13. The differences will be described below.

  In step S13, the exhaust temperature is increased by increasing the opening of the variable nozzle (vane) 10C on the turbine 10A side of the turbocharger 10 for the inlet exhaust temperature of the DPF 21 that has decreased as the post injection amount decreases. Ensure the required DPF regeneration temperature. Increasing the opening degree of the variable nozzle (vane) 10C on the turbine 10A side of the turbocharger 10 causes the exhaust energy to be discarded without being recovered by the turbo 10, so that the temperature of the exhaust gas flowing downstream increases.

  The method for raising the exhaust temperature in the present embodiment is used as a temporary emergency because turbocharging is impeded and engine output is reduced.

  In the present embodiment, in addition to the effect (a) in the first embodiment, the following effects can be achieved.

  (D) When it is determined that the pre-stage catalyst 20 is deteriorated, the amount of HC contained in the exhaust gas by the post injection is reduced, and the supercharger disposed across the exhaust passage 11 and the intake passage 12 Since the exhaust gas temperature is raised by opening the opening of the variable nozzle 10C on the turbine 10A side of the engine 10, the engine output performance is lowered and the drivability of the vehicle is lowered. The regeneration of the filter 21 can be continued effectively.

The system block diagram of the regeneration control apparatus of the particulate filter which shows one Embodiment of this invention. Explanatory drawing explaining the fuel-injection state before deterioration (A) and after deterioration (B) of a pre-stage catalyst. Time chart (A) showing each change in the normal state, deterioration progress state, post-injection amount in each state after deterioration determination, exhaust gas temperature after passing through the front stage catalyst, and DPF inlet HC concentration, and this embodiment The time chart which shows each change of the front | former stage catalyst and DPF inlet_port | entrance in (B). The flowchart figure of the reproduction | regeneration control based on 1st Embodiment. The flowchart figure of the reproduction | regeneration control based on 2nd Embodiment. The flowchart figure of the reproduction | regeneration control based on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine, engine main body 2 Common rail 3 Fuel injection valve 4 Supply pump 5 Combustion chamber 6 EGR passage 7 EGR valve 10 Supercharger 10A Exhaust turbine, turbine 10B Compressor 10C Variable nozzle 11 Exhaust passage 12 Intake passage 20 Pre-stage catalyst, oxidation catalyst 21 Particulate filter, filter, DPF
22, 23 Temperature sensor 24 Differential pressure sensor 26 Control unit

Claims (6)

A pre-stage catalyst having an oxidizing ability provided in an exhaust passage of an internal combustion engine, a particulate filter provided downstream of the pre-stage catalyst and carrying a catalyst that captures particulate matter in the exhaust, and HC from the upstream of the pre-stage catalyst A particulate filter that regenerates the filter by removing particulate matter trapped in the particulate filter by reacting the HC supplied by the HC supply means with the preceding catalyst. Playback control device,
A deterioration state determining means for determining a deterioration state of the preceding catalyst;
Control means for reducing the amount of HC supplied by the HC supply means and increasing the temperature of exhaust gas discharged from the internal combustion engine when the deterioration of the pre-stage catalyst is determined by the deterioration state determination means. A particulate filter regeneration control device. The HC supply means controls the supply amount of HC contained in exhaust gas by post-injection of fuel into a cylinder by a fuel injection valve of an internal combustion engine,
2. The particulate filter regeneration control device according to claim 1, wherein the control means raises the temperature of the exhaust gas by delaying a combustion end timing in the cylinder of the fuel injected by the fuel injection valve. 3. . The HC supply means controls the supply amount of HC contained in exhaust gas by post-injection of fuel into a cylinder by a fuel injection valve of an internal combustion engine,
The said control means raises the temperature of exhaust gas by delaying the completion | finish time of combustion in a cylinder by the after injection between the main injection by the said fuel injection valve, and post injection. Particulate filter regeneration control device. The HC supply means controls the supply amount of HC contained in exhaust gas by post-injection of fuel into a cylinder by a fuel injection valve of an internal combustion engine,
3. The regeneration of the particulate filter according to claim 2, wherein the control means raises the temperature of the exhaust gas by delaying the combustion end timing in the cylinder by delaying the main injection by the fuel injection valve. Control device. The HC supply means controls the supply amount of HC contained in exhaust gas by post-injection of fuel into a cylinder by a fuel injection valve of an internal combustion engine,
The control means reduces the excess air ratio of the exhaust gas by reducing the opening degree of the throttle valve disposed in the intake passage or the exhaust passage or increasing the opening degree of the EGR valve provided in the EGR passage. 2. The particulate filter regeneration control apparatus according to claim 1, wherein the temperature of the exhaust gas is increased by the control. The HC supply means controls the supply amount of HC contained in exhaust gas by post-injection of fuel into a cylinder by a fuel injection valve of an internal combustion engine,
The said control means raises the temperature of exhaust gas by opening the variable nozzle opening degree by the side of the turbine of the supercharger arrange | positioned ranging over an exhaust passage and an intake passage. Particulate filter regeneration control device.