JP2010203377A - Control device for internal combustion engine system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently perform catalyst regeneration processing, while suppressing overheat of an exhaust system. <P>SOLUTION: An internal combustion system includes: an internal combustion engine; a variable displacement turbocharger having a variable nozzle; and an exhaust cleaning catalyst. The control device for an internal combustion engine system controls the internal combustion system having the above constitution, and includes a catalyst regeneration means and a variable nozzle opening control means. The catalyst regeneration means controls an air-fuel ratio of exhaust to be on a rich side to perform regeneration processing of the exhaust cleaning catalyst. The variable nozzle opening control means increases the opening of the variable nozzle in the regeneration processing of the exhaust cleaning catalyst by the catalyst regeneration means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention controls an internal combustion engine system including an internal combustion engine, a variable displacement turbocharger interposed in the intake passage and the exhaust passage of the internal combustion engine, and an exhaust purification catalyst interposed in the exhaust passage. The present invention relates to an internal combustion engine system control device.

  As this type of device, for example, those disclosed in Japanese Patent Application Laid-Open Nos. 2003-41930 and 2008-169753 are known. These devices are configured to control the opening of the variable nozzle in the variable displacement turbocharger according to the state of the exhaust purification catalyst.

  For example, the apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-41930 includes a NOx storage reduction catalyst (Japanese Patent Application Laid-Open Nos. 5-168860, 5-317562, 6-31139, 2002). No. -79095, etc.) and a particulate filter (see JP-A-5-222914, JP-A-2003-161137, etc.) are provided.

The NOx storage reduction catalyst, when a high oxygen concentration in the inflowing exhaust gas while absorbing the NOx, when the concentration is low a catalyst having a function of releasing while reducing NOx to N _2. The particulate filter is a filter for collecting particulate matter (Particulate Matter: abbreviated as “PM”) which is a suspended particulate matter contained in exhaust gas.

If a lean air-fuel ratio exhaust gas continues to be supplied to the NOx storage reduction catalyst, the NOx absorption capacity of the catalyst is saturated, and NOx is leaked downstream of the catalyst (particularly, the internal combustion engine is So-called lean burn operation). Therefore, by reducing the oxygen concentration of the inflowing exhaust gas and increasing the amount of HC components in the exhaust gas at a predetermined timing before the NOx absorption capacity is saturated, NOx absorbed by the catalyst is reduced to N _2. However, it is necessary to recover the NOx absorption capacity by releasing it.

  Such NOx storage reduction catalyst also absorbs sulfur oxide (SOx) generated by combustion of the sulfur content contained in the fuel. Absorbed SOx is less likely to be released than NOx and accumulates in the catalyst (SOx poisoning). Since the NOx purification rate decreases due to this SOx poisoning, it is necessary to perform a treatment for recovering from the SOx poisoning at an appropriate time on the catalyst. This SOx poisoning recovery process is performed by circulating exhaust gas having a reduced oxygen concentration through the catalyst while keeping the catalyst at a high temperature (eg, about 600 to 650 ° C.).

  Further, when particulate matter accumulates on the particulate filter and the filter is clogged, the pressure of the exhaust gas upstream of the filter increases, which may cause problems such as a decrease in engine output. Therefore, when the amount of particulate matter accumulated in the filter increases, a filter regeneration process is performed in which the accumulated particulate matter is removed by oxidation (ignition combustion).

  In the apparatus having the above-described configuration (refer to Japanese Patent Application Laid-Open No. 2003-41930, etc.), in the SOx poisoning recovery process, a process for reducing the oxygen concentration in the exhaust gas after the catalyst temperature increasing process is executed. Is done.

  In the catalyst temperature raising process, the variable nozzle is opened. Then, the flow rate of the exhaust gas blown to the turbine is reduced, and the rotational speed of the turbine is reduced, whereby the intake air amount is reduced. As a result, the exhaust temperature rises, thereby raising the catalyst temperature. Conversely, when the exhaust temperature rises excessively, the variable nozzle is closed. Then, the flow rate of the exhaust gas blown to the turbine is increased and the rotational speed of the turbine is increased, so that the intake air amount is increased. As a result, the exhaust temperature is lowered, and thereby the catalyst temperature is lowered. When the catalyst temperature (bed temperature) rises to a high temperature range of about 600 ° C. to 650 ° C. by such catalyst temperature raising processing, poisoning elimination processing for reducing the oxygen concentration in the exhaust is performed.

  In such an apparatus, the filter regeneration process is specifically performed as follows. First, the variable nozzle is fully opened. Then, the flow rate of the exhaust gas blown to the turbine is lowered and the rotational speed of the turbine is lowered, so that the intake air amount is reduced. As a result, the exhaust temperature rises, thereby raising the catalyst temperature. This increase in the catalyst temperature promotes the oxidation of particulate matter. Further, by fully opening the variable nozzle, it is possible to suppress the loss of exhaust energy in the turbocharger, thereby suppressing a decrease in exhaust temperature.

  In this type of apparatus, the supply of exhaust gas having a low oxygen concentration (rich air-fuel ratio) for regeneration processing of the exhaust purification catalyst (including NOx absorption capacity recovery processing and filter regeneration processing) is relatively long. It may be necessary to perform the time (for example, about several seconds: continuously or intermittently) (for example, when the amount of NOx or SOx adsorbed or the amount of particulate matter deposited has reached the limit).

  Here, when the air-fuel ratio of the exhaust gas is made rich, the exhaust gas temperature becomes high. Therefore, even in the above-described case, the duration of the regeneration process can be secured until the regeneration of the exhaust purification catalyst is sufficiently achieved due to the heat resistant temperature of the exhaust system (for example, the exhaust manifold). There is a risk of disappearing.

  The present invention has been made to cope with such a problem. That is, an object of the present invention is to provide an internal combustion engine system control apparatus that can sufficiently perform a catalyst regeneration process while suppressing overheating of the exhaust system.

  An internal combustion engine system to which the present invention is applied includes an internal combustion engine, a variable displacement turbocharger interposed in an intake passage and an exhaust passage of the internal combustion engine, an exhaust purification catalyst interposed in the exhaust passage, It has. The variable displacement turbocharger includes a turbine that is rotated by exhaust gas that is blown, and a variable nozzle that makes the flow rate of the exhaust gas blown to the turbine variable. As the exhaust purification catalyst, an NOx storage reduction catalyst can be used.

  An internal combustion engine system control apparatus according to the present invention controls an internal combustion engine system having the above-described configuration, and includes catalyst regeneration means and variable nozzle opening control means. The catalyst regeneration means regenerates the exhaust purification catalyst by controlling the air-fuel ratio of the exhaust to a rich side. The variable nozzle opening control means controls the opening of the variable nozzle.

  The feature of the present invention resides in that the variable nozzle opening degree control means increases the opening degree of the variable nozzle during the regeneration process of the exhaust purification catalyst by the catalyst regeneration means. Specifically, for example, during the SOx poisoning recovery process, the catalyst regeneration means continuously enriches the fuel mixture in the combustion chamber for a predetermined time so as to control the air-fuel ratio of the exhaust to the rich side. It has become. At this time, the variable nozzle opening control means increases the opening of the variable nozzle in order to suppress overheating of the exhaust manifold due to an increase in exhaust temperature during the SOx poisoning recovery process by the catalyst regeneration means. It has become.

  In the internal combustion engine system control apparatus of the present invention having such a configuration, the exhaust air-fuel ratio is controlled to the rich side during the regeneration process of the exhaust purification catalyst. At this time, the opening degree of the variable nozzle is increased more than before the regeneration process.

  Then, the exhaust gas is quickly flowed to the downstream side of the variable capacity turbocharger. Thereby, the residence time of the exhaust gas in the exhaust manifold and the increase in the exhaust pressure (P4) at the inlet of the turbine are suppressed. Therefore, overheating of the exhaust manifold is suppressed. In particular, even when the regeneration process of the exhaust purification catalyst is performed for a relatively long time (intermittently or continuously) as in the SOx poisoning recovery process, overheating of the exhaust manifold is suppressed well. The

  Therefore, according to the present invention, it is possible to sufficiently perform the catalyst regeneration process while suppressing overheating of the exhaust manifold.

1 is a schematic diagram showing an overall configuration of an internal combustion engine system to which an embodiment of the present invention is applied. It is a graph which shows the effect confirmation result by the internal combustion engine system 1 of this embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the description about the following embodiment is specific to the extent possible, merely an example of the embodiment of the present invention in order to satisfy the description requirement (description requirement / practicability requirement) of the specification required by law. It is only what is described in. Therefore, as will be described later, it is quite natural that the present invention is not limited to the specific configurations of the embodiments described below. Various modifications that can be made to the present embodiment are listed together at the end, as they would interfere with the understanding of the consistent description of the embodiment if inserted during the description of the embodiment. .

<Configuration>
FIG. 1 is a schematic diagram showing an overall configuration of an internal combustion engine system 1 to which an embodiment of the present invention is applied. Referring to FIG. 1, the internal combustion engine system 1 in the present embodiment includes an internal combustion engine 2, a fuel injection device 3, an intake / exhaust device 4, and a control device 5.

  The internal combustion engine 2 of the present embodiment is a diesel engine as a compression ignition engine. In the present embodiment, the internal combustion engine 2 has a plurality (four in FIG. 1) of combustion chambers 21 arranged in series.

<< Fuel injection device >>
The fuel injection device 3 includes the same number of injectors 31 as the combustion chambers 21. That is, each injector 31 is attached to the internal combustion engine 2 so as to correspond to each combustion chamber 21. The injector 31 of the present embodiment has a known piezo-type configuration, and is configured so that fuel can be directly injected into the combustion chamber 21. Each injector 31 is connected to a common rail 32 via a fuel supply pipe 33. A fuel pump 36 is interposed in the fuel supply passage 35 between the common rail 32 and the fuel tank 34.

<< Intake and exhaust system >>
The intake manifold 41 is attached to the internal combustion engine 2 so that air (including recirculated exhaust gas) can be supplied to each combustion chamber 21. The intake manifold 41 is connected to the intake pipe 42. The intake manifold 41 and the intake pipe 42 correspond to the intake passage of the present invention.

  An air cleaner 43 and a throttle 44 are interposed in the intake pipe 42. The throttle 44 is provided immediately before the intake manifold 41, and is driven by a throttle actuator 44a composed of a stepping motor or the like.

  The exhaust manifold 45 is attached to the internal combustion engine 2 so as to receive the exhaust from each combustion chamber 21. The exhaust manifold 45 is connected to the exhaust pipe 46. The exhaust manifold 45 and the exhaust pipe 46 correspond to the exhaust passage of the present invention.

  A turbocharger 47 is interposed in the intake pipe 42 and the exhaust pipe 46. That is, the intake pipe 42 is connected to the compressor 47 a side of the turbocharger 47, and the exhaust pipe 46 is connected to the turbine 47 b side of the turbocharger 47. The compressor 47 a is interposed in the intake pipe 42 at a position between the air cleaner 43 and the throttle 44.

  The turbocharger 47 in this embodiment is of a so-called variable capacity type. That is, the turbocharger 47 includes a turbine rotor 47b1 that is rotated by the exhaust gas that is blown, and a variable nozzle 47b2 that makes the flow rate of the exhaust gas blown to the turbine rotor 47b1 variable. Specifically, the movable variable nozzle 47b2 is provided at a position facing the turbine rotor 47b1. The variable nozzle 47b2 is driven by a nozzle vane actuator 47b3.

  In the present embodiment, the internal combustion engine system 1 is provided with an EGR device 48 (EGR is an abbreviation for exhaust gas recirculation). The EGR device 48 includes an EGR passage 48a, an EGR valve 48b, and an EGR valve actuator 48c.

  The EGR passage 48 a is a passage for EGR gas (recirculation exhaust), and is provided so as to connect the intake manifold 41 and the exhaust manifold 45. An EGR valve 48b is interposed in the EGR passage 48a. The EGR valve 48b is driven by an EGR valve actuator 48c to control the supply amount of EGR gas to the intake manifold 41 (that is, to control the EGR rate).

  An exhaust purification catalyst 49 is interposed downstream of the turbocharger 47 in the exhaust pipe 46. In the exhaust purification catalyst 49 in the present embodiment, an NOx storage reduction catalyst, a particulate filter, and an oxidation catalyst having an oxygen storage / release function for promoting oxidation purification of unburned substances (HC and CO) in the exhaust gas are provided. Are arranged in this order along the exhaust flow direction.

<< Control device >>
The control device 5 as an embodiment of the internal combustion engine system control device of the present invention controls the operation of the internal combustion engine system 1 including the internal combustion engine 2, the fuel injection device 3, and the intake / exhaust device 4. The control device 5 includes an electronic control unit (ECU) 50 that constitutes the catalyst regeneration means and the variable nozzle opening degree control means of the present invention.

  The ECU 50 includes a CPU (microprocessor) 50a, a ROM (read only memory) 50b, a RAM (random access memory) 50c, a backup RAM 50d, an interface 50e, and a bidirectional bus 50f. The CPU 50a, ROM 50b, RAM 50c, backup RAM 50d, and interface 50e are connected to each other by a bidirectional bus 50f.

  The CPU 50 a is configured to execute a routine (program) for controlling the operation of each part in the internal combustion engine system 1. The ROM 50b stores in advance a routine executed by the CPU 50a, a table (lookup table, map), parameters, and the like. The RAM 50c is configured to temporarily store data as necessary when the CPU 50a executes a routine. The backup RAM 50d is configured to store data when the CPU 50a executes a routine while the power is turned on, and to store the stored data even after the power is turned off.

  The interface 50e is electrically connected to various sensors described later, and is configured to transmit detection signals from these sensors to the CPU 50a. The interface 50e is electrically connected to operating parts such as the injector 31, the throttle actuator 44a, the nozzle vane actuator 47b3, and the EGR valve actuator 48c. That is, the control device 5 receives the detection signal from each of the sensors described above via the interface 50e, and sends the operation signal to each operation unit based on the calculation result of the CPU 50a corresponding to the detection signal. It is configured.

  The air flow meter 51 is interposed in the intake pipe 42 on the upstream side of the compressor 47 a of the turbocharger 47. The air flow meter 51 is configured to generate an output voltage corresponding to the mass flow rate per unit time of the intake air flowing in the intake pipe 42. The intake pressure sensor 52 is interposed at a position downstream of the throttle 44 in the intake pipe 42. The intake pressure sensor 52 is configured to generate an output voltage corresponding to the pressure of intake air supplied to the intake manifold 41.

  The exhaust manifold temperature sensor 53 is attached to the exhaust manifold 45. The exhaust manifold temperature sensor 53 is configured to generate an output voltage corresponding to the temperature of the exhaust manifold 45. The catalyst bed temperature sensor 54 is attached to the exhaust purification catalyst 49. The catalyst bed temperature sensor 54 is configured to generate an output voltage corresponding to the temperature of the exhaust purification catalyst 49 (catalyst bed temperature).

  The catalyst upstream side exhaust air-fuel ratio sensor 55 is interposed in the exhaust pipe 46 downstream of the turbine 47 b of the turbocharger 47 and upstream of the exhaust purification catalyst 49. The catalyst upstream side exhaust air-fuel ratio sensor 55 is configured to generate an output voltage corresponding to the concentration of each component (NOx, etc.) in the exhaust gas upstream of the exhaust purification catalyst 49.

  Similarly, the catalyst downstream side exhaust air-fuel ratio sensor 56 is interposed in the exhaust pipe 46 on the downstream side of the exhaust purification catalyst 49. The catalyst downstream side exhaust air-fuel ratio sensor 56 is configured to generate an output voltage corresponding to the concentration of each component (NOx, etc.) in the exhaust gas downstream of the exhaust purification catalyst 49.

  The catalyst upstream exhaust pressure sensor 57 is interposed at a position in the exhaust pipe 46 immediately before the exhaust purification catalyst 49. The catalyst upstream exhaust pressure sensor 57 is configured to generate an output voltage corresponding to the exhaust pressure at a position immediately before the exhaust purification catalyst 49 in the exhaust pipe 46.

  Similarly, the catalyst downstream exhaust pressure sensor 58 is interposed at a position immediately after the exhaust purification catalyst 49 in the exhaust pipe 46. The catalyst downstream exhaust pressure sensor 58 is configured to generate an output voltage corresponding to the exhaust pressure at a position immediately after the exhaust purification catalyst 49 in the exhaust pipe 46.

  The rail pressure sensor 59 is attached to the common rail 32. The rail pressure sensor 59 is configured to generate an output voltage corresponding to the pressure in the common rail 32.

<Operations and effects according to the embodiment>
Next, the outline | summary of operation | movement of the internal combustion engine system 1 of this embodiment is demonstrated. During normal operation, the ECU 50 controls the injector 31, the throttle actuator 44a, the nozzle vane actuator 47b3, EGR according to the target air-fuel ratio and the target boost pressure set based on the engine operating state such as the engine speed and load. The operation of the valve 48b, etc. is feedback controlled.

  On the other hand, during the regeneration process for recovering the capacity of the exhaust purification catalyst 49, control different from that during the normal operation is performed.

  For example, when the internal combustion engine 2 is operated in a so-called lean combustion operation, a lean air-fuel ratio exhaust gas continues to be supplied to the NOx storage reduction catalyst provided in the exhaust purification catalyst 49. Then, NOx continues to be absorbed by the NOx catalyst. Moreover, the NOx purification rate in the NOx catalyst is reduced by SOx poisoning.

  Therefore, the control device 5 (ECU 50) of the present embodiment, based on the outputs of the catalyst upstream side exhaust air / fuel ratio sensor 55 and the catalyst downstream side exhaust air / fuel ratio sensor 56, performs NOx absorption capacity recovery processing (SOx coverage) at an appropriate time. (Including poison recovery process). During the NOx absorption capacity recovery process, the air-fuel ratio of the exhaust supplied to the exhaust purification catalyst 49 is enriched. The enrichment of the air-fuel ratio of the exhaust is, for example, at least of the fuel injection amount by the injector 31 (particularly so-called after injection amount), the opening degree of the throttle 44 (closed), and the opening degree of the EGR valve 48b (closed). Done by one.

  In the recovery process when the NOx absorption amount increases, the air-fuel ratio of the exhaust gas is enriched in a short time with a relatively short cycle (so-called rich spike). On the other hand, in the SOx poisoning recovery process, it is necessary to continuously enrich the exhaust air-fuel ratio for a relatively long time (for example, several seconds).

  Further, when particulate matter accumulates on the particulate filter provided in the exhaust purification catalyst 49 and the filter is clogged, the pressure of the exhaust gas upstream of the filter increases, which causes a decrease in engine output, etc. There is a risk of malfunction.

  Therefore, the control device 5 (ECU 50) of the present embodiment executes filter regeneration processing at an appropriate time based on the outputs of the catalyst upstream exhaust pressure sensor 57 and the catalyst downstream exhaust pressure sensor 58. Also during the filter regeneration process, the air-fuel ratio of the exhaust supplied to the exhaust purification catalyst 49 is enriched.

  As described above, the control device 5 (ECU 50) of the present embodiment continuously converts the fuel mixture in the combustion chamber 21 for a predetermined time during the regeneration process of the exhaust purification catalyst 49 (NOx absorption capacity recovery process and filter regeneration process). By enriching, the air-fuel ratio of the exhaust is controlled to the rich side. Further, the control device 5 (ECU 50) of the present embodiment increases the opening of the variable nozzle 47b2 in order to suppress overheating of the exhaust manifold 45 due to the increase in the exhaust temperature during the regeneration process.

  As a result, the exhaust gas is quickly flowed downstream of the turbocharger 47. Then, the residence time of the exhaust gas in the exhaust manifold 45 and the increase in the exhaust pressure (P4) at the inlet of the turbine 47b are suppressed. Therefore, even if the regeneration process of the exhaust purification catalyst 49 is performed for a relatively long time (intermittently or continuously), overheating of the exhaust manifold 45 is satisfactorily suppressed. Therefore, according to the configuration of the present embodiment, the catalyst regeneration process can be sufficiently performed while the overheating of the exhaust manifold 45 is suppressed.

  Further, according to the configuration of the present embodiment, the opening energy of the variable nozzle 47b2 is increased during the regeneration process of the exhaust purification catalyst 49, so that the energy of the exhaust gas is quickly supplied to the exhaust purification catalyst 49. Thereby, the fall of a catalyst bed temperature is suppressed. Furthermore, the turbo surge can be satisfactorily suppressed by enriching the air-fuel ratio by opening (closing) the throttle 44. In addition, a fuel consumption reduction effect can be obtained by suppressing an increase in the exhaust pressure (P4) at the inlet of the turbine 47b.

  FIG. 2 is a graph showing an effect confirmation result by the internal combustion engine system 1 of the present embodiment. FIG. 2 shows a state where the lean burn operation mode during normal operation and the SOx poisoning recovery processing mode are repeatedly executed.

  In the figure, (i) is the throttle degree of the variable nozzle 47b2, (ii) is the temperature of the exhaust manifold 45, (iii) is the intake pressure, (iv) is the fuel injection amount, and (v) is at the inlet of the exhaust purification catalyst 49. The exhaust temperature is shown. Further, in the figure, a thick line indicates the control (example) of the present embodiment, and a thin line indicates a comparative example. The comparative example is the same operating condition as the example except that the throttle degree of the variable nozzle 47b2 is maintained at 100% (fully closed) in the SOx poisoning recovery processing mode.

  As is clear from FIG. 2, in the case of the embodiment, the temperature increase of the exhaust manifold 45 is suppressed as compared with the case of the comparative example (see (i) and (ii) in the figure). Therefore, according to the control of the present embodiment, it is possible to significantly increase the duration of the SOx poisoning recovery processing mode (about 2 seconds in the figure) compared to the comparative example (FIG. 2). (See middle (iii) and (iv)).

  On the other hand, in the embodiment, the exhaust temperature at the inlet of the exhaust purification catalyst 49 is higher than in the comparative example. Therefore, according to the control of the present embodiment, the retention of the catalyst bed temperature is also improved.

<List of examples of modification>
Note that, as described above, the above-described embodiments are merely examples of typical embodiments of the present invention that the applicant has considered to be the best at the time of filing of the present application. Therefore, the present invention is not limited to the above-described embodiment.

  Therefore, it goes without saying that various modifications can be made to the above-described embodiment within the scope not changing the essential part of the present invention.

  Hereinafter, some typical modifications will be exemplified. However, it goes without saying that the modifications are not limited to those listed below. In addition, a plurality of modified examples can be applied in a composite manner as appropriate within a technically consistent range.

  The present invention (especially those expressed functionally and functionally in the constituent elements constituting the means for solving the problems of the present invention) is based on the above-described embodiment and the description of the following modifications. Should not be interpreted as limited. Such a limited interpretation is unacceptable and improper for imitators, while improperly harming the applicant's interests (rushing to file under a prior application principle).

  (A) The present invention is not limited to the specific apparatus configuration disclosed in the above embodiment. For example, the internal combustion engine 2 is not limited to a diesel engine. There is no particular limitation on the number of cylinders and the cylinder arrangement method. The throttle 44 can be interposed upstream of the turbocharger 47 (compressor 47a). The NOx storage reduction catalyst, the particulate filter, and the oxidation catalyst can be interposed in the exhaust pipe 46 in a separated state.

  Further, the present invention is not limited to the case where the exhaust purification catalyst 49 includes an NOx storage reduction catalyst, a particulate filter, and an oxidation catalyst. Specifically, for example, when the exhaust purification catalyst 49 does not include an oxidation catalyst and / or when the exhaust purification catalyst 49 includes only one of a storage reduction type NOx catalyst and a particulate filter. However, the present invention can be suitably applied.

  (B) The present invention is not limited to the specific processing disclosed in the above embodiment. For example, enrichment of the air-fuel ratio of the exhaust supplied to the exhaust purification catalyst 49 may be performed by fuel injection by an exhaust enrichment injector interposed in the exhaust passage.

  Further, at least one of the intake pressure, the temperature of the exhaust manifold 45, and the catalyst bed temperature can be estimated onboard. In this case, at least one of the intake pressure sensor 52, the exhaust manifold temperature sensor 53, and the catalyst bed temperature sensor 54 may be omitted.

  (C) Other modifications not specifically mentioned are naturally included in the scope of the present invention as long as they do not change the essential part of the present invention.

  In addition, in each element constituting the means for solving the problems of the present invention, the elements expressed in terms of operation and function are the specific structures disclosed in the above-described embodiments and modifications, It includes any structure that can realize this action / function. Furthermore, the contents (including the specification and the drawings) of each publication cited in this specification can be incorporated as part of this specification.

DESCRIPTION OF SYMBOLS 1 ... System 2 ... Internal combustion engine 21 ... Combustion chamber 3 ... Fuel injection device 31 ... Injector 32 ... Common rail 4 ... Intake / exhaust device 42 ... Intake pipe
44 ... Throttle 44a ... Throttle actuator 45 ... Exhaust manifold 46 ... Exhaust pipe 47 ... Turbocharger 47b ... Turbine 47b2 ... Variable nozzle 48 ... EGR device 48a ... EGR passage 48b ... EGR valve 48c ... EGR valve actuator 5 ... Control device 50 ... ECU 50a ... CPU
52 ... Intake pressure sensor 53 ... Exhaust manifold temperature sensor 55 ... Catalyst upstream side exhaust air / fuel ratio sensor 56 ... Catalyst downstream side exhaust air / fuel ratio sensor 57 ... Catalyst upstream side exhaust pressure sensor 58 ... Catalyst downstream side exhaust pressure sensor

JP 2001-82134 A JP 2003-41930 A Japanese Patent Laid-Open No. 2004-3411 JP 2008-169753 A

Claims (2)

An internal combustion engine;
A variable displacement turbocharger that is interposed in an intake passage and an exhaust passage of the internal combustion engine and includes a turbine that rotates by blown exhaust and a variable nozzle that varies a flow rate of exhaust blown to the turbine;
An exhaust purification catalyst interposed in the exhaust passage;
An internal combustion engine system control device for controlling an internal combustion engine system comprising:
Catalyst regeneration means for performing regeneration treatment of the exhaust purification catalyst by controlling the air-fuel ratio of the exhaust to a rich side;
Variable nozzle opening control means for increasing the opening of the variable nozzle during the regeneration process of the exhaust purification catalyst by the catalyst regeneration means;
An internal combustion engine system control device comprising: The internal combustion engine system control device according to claim 1,
The exhaust purification catalyst is an NOx storage reduction catalyst,
The catalyst regeneration means controls the air-fuel ratio of the exhaust to the rich side by continuously enriching the fuel mixture in the combustion chamber for a predetermined time during the SOx poisoning recovery process as the regeneration process of the exhaust purification catalyst. ,
The variable nozzle opening degree control means increases the opening degree of the variable nozzle in order to suppress overheating of the exhaust manifold due to an increase in exhaust temperature during the SOx poisoning recovery process by the catalyst regeneration means. , An internal combustion engine system control device.

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