US20090249768A1 - Exhaust Purification System of Internal Combustion Engine - Google Patents

Exhaust Purification System of Internal Combustion Engine Download PDF

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Publication number
US20090249768A1
US20090249768A1 US12/227,718 US22771807A US2009249768A1 US 20090249768 A1 US20090249768 A1 US 20090249768A1 US 22771807 A US22771807 A US 22771807A US 2009249768 A1 US2009249768 A1 US 2009249768A1
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Prior art keywords
sox
feed
exhaust gas
sox trap
temperature
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Abandoned
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US12/227,718
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English (en)
Inventor
Takamitsu Asanuma
Shinya Hirota
Kotaro Hayashi
Kohei Yoshida
Atsushi Hayashi
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Toyota Motor Corp
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Toyota Motor Corp
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Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA reassignment TOYOTA JIDOSHA KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HAYASHI, KOTARO, HAYASHI, ATSUSHI, HIROTA, SHINYA, ASANUMA, TAKAMITSU, YOSHIDA, KOHEI
Publication of US20090249768A1 publication Critical patent/US20090249768A1/en
Abandoned legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404—Removing only nitrogen compounds
    • B01D53/9409—Nitrogen oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/90—Injecting reactants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9495—Controlling the catalytic process
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/0842—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/085—Sulfur or sulfur oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
    • F01N3/0885—Regeneration of deteriorated absorbents or adsorbents, e.g. desulfurization of NOx traps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/105—General auxiliary catalysts, e.g. upstream or downstream of the main catalyst
    • F01N3/106—Auxiliary oxidation catalysts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N9/00—Electrical control of exhaust gas treating apparatus
    • F01N9/002—Electrical control of exhaust gas treating apparatus of filter regeneration, e.g. detection of clogging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/021—Introducing corrections for particular conditions exterior to the engine
    • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
    • F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
    • F02D41/0285—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a SOx trap or adsorbent
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
    • F02D41/402—Multiple injections
    • F02D41/405—Multiple injections with post injections
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/208—Hydrocarbons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/30—Sulfur compounds
    • B01D2257/302—Sulfur oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/03—Adding substances to exhaust gases the substance being hydrocarbons, e.g. engine fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
    • F01N2900/06—Parameters used for exhaust control or diagnosing
    • F01N2900/16—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust apparatus, e.g. particulate filter or catalyst
    • F01N2900/1612—SOx amount trapped in catalyst
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Definitions

  • the present invention relates to an exhaust purification system of an internal combustion engine.
  • Japanese Patent Publication (A) No. 6-173652 describes an internal combustion engine providing an exhaust purification system absorbing NOx (nitrogen oxides) in the exhaust gas in an exhaust passage.
  • the exhaust gas also contains SOx.
  • the NOx absorbent described in Japanese Patent Publication (A) No. 6-173652 absorbs SOx in addition to NOx so the amount of NOx which the NOx absorbent can absorb ends up being reduced by exactly the amount of absorption of SOx.
  • an SOx absorbent for absorbing SOx in the exhaust gas is arranged upstream of the NOx absorbent and the SOx absorbent is used to absorb the SOx in the exhaust gas and prevent SOx from flowing into the NOx absorbent.
  • an SOx absorbent absorbs the SOx in the exhaust gas when the air-fuel ratio of the exhaust gas flowing into it is an air-fuel ratio leaner than the stoichiometric air-fuel ratio and the temperature of the SOx absorbent is higher than a so-called activation temperature.
  • the SOx absorbent releases SOx when the air-fuel ratio of the exhaust gas flowing into it becomes the stoichiometric air-fuel ratio or an air-fuel ratio richer than that and the temperature of the SOx absorbent becomes higher than a certain temperature higher than the activation temperature (hereinafter referred to as the “SOx release temperature”).
  • the SOx absorbent has the absorption of SOx in the exhaust gas as its inherent function, so when the SOx absorbent should be made to absorb SOx, it is not preferable that the SOx absorbent end up releasing SOx. Further, this applies not only to an exhaust purification system provided with an SOx absorbent for the purpose of absorbing the SOx in the exhaust gas, but also broadly to an exhaust purification system provided with an SOx trap for the purpose of trapping the SOx in the exhaust gas.
  • An object of the present invention is to reliably prevent an SOx trap from ending up releasing SOx when the SOx trap should be made to trap SOx in an internal combustion engine provided with an SOx trap trapping the SOx in the exhaust gas.
  • an exhaust purification system of an internal combustion engine providing an SOx trap for trapping the SOx in the exhaust gas inside an exhaust passage, the SOx trap trapping the SOx in the exhaust gas when an air-fuel ratio of the exhaust gas flowing into the SOx trap is an air-fuel ratio leaner than a stoichiometric air-fuel ratio and a temperature of the SOx trap is lower than a predetermined temperature and releasing the trapped SOx when the air-fuel ratio of the exhaust gas flowing into the SOx trap is the stoichiometric air-fuel ratio or an air-fuel ratio richer than that and the temperature of the SOx trap is higher than the predetermined temperature and executing HC feed control feeding HC into the exhaust gas upstream of the SOx trap when a predetermined condition stands, which exhaust purification system of an internal combustion engine executes, as the HC feed control, first HC feed control feeding HC into the exhaust gas upstream of the SOx trap by a predetermined pattern when the amount
  • a predetermined amount of HC is fed into the exhaust gas upstream of the SOx trap per unit time, while in the second HC feed control, an amount of HC smaller than the predetermined amount is fed into the exhaust gas upstream of the SOx trap per unit time.
  • HC with a higher diffusion ability into the exhaust gas than the HC fed into the exhaust gas upstream of the SOx trap in the first HC feed control is fed into the exhaust gas upstream of the SOx trap.
  • HC is fed into the exhaust gas upstream of the SOx trap so that a lean degree of the air-fuel ratio of the exhaust gas flowing into the SOx trap is kept larger than a predetermined lean degree.
  • the predetermined lean degree is set larger the lower the temperature of the SOx trap.
  • HC in the second HC feed control, HC is fed into the exhaust gas upstream of the SOx trap so that the amount of local temperature rise of the SOx trap per unit time is kept smaller than the amount of local temperature rise of the SOx trap per unit time allowed in the first HC feed control.
  • HC in the second HC feed control, HC is fed into the exhaust gas upstream of the SOx trap so that an amount of temperature rise of the SOx trap as a whole per unit time is kept smaller than an amount of temperature rise of the SOx trap as a whole per unit time allowed in the first HC feed control.
  • a particulate filter trapping particulate matter in the exhaust gas is arranged in the exhaust passage downstream of the SOx trap, one predetermined condition is a fuel removal condition where it is judged if the temperature of the particulate filter should be raised to a predetermined target temperature to burn away particulate matter trapped by the particulate filter, and, when the second HC feed control is executed when the burnaway condition stands, in the second HC feed control, HC is fed into the exhaust gas upstream of the SOx trap using as a target temperature a temperature lower than the target temperature in the first HC feed control in the case where the first HC feed control is executed when the burnaway condition stands.
  • HC in the second HC feed control, HC is fed into the exhaust gas upstream of the SOx trap so that a temperature amplitude of the SOx is kept smaller than a temperature amplitude of the SOx trap allowed in the first HC feed control.
  • an NOx absorbent absorbing the NOx in the exhaust gas is arranged in the exhaust passage downstream of the SOx trap, one predetermined condition is an NOx release condition where it is judged that the NOx absorbent should release NOx, and, when the second HC feed control is executed when the NOx release condition stands, in the second HC feed control, HC is fed into the exhaust gas upstream of the SOx trap so that a temperature amplitude of the SOx trap is kept smaller than a temperature amplitude of the SOx trap allowed in the first HC feed control in the case where the first HC feed control is executed when the NOx release condition stands.
  • an oxidation catalyst provided with an oxidizing ability higher than even the oxidizing ability of the SOx trap is arranged in the exhaust passage upstream of the SOx trap.
  • FIG. 1 is a view showing a compression ignition type of internal combustion engine provided with an exhaust purification system of the present invention.
  • FIGS. 2(A) and (B) are views showing the structure of a particulate filter.
  • FIG. 3 is a cross-sectional view of a surface part of a catalyst carrier of an NOx catalyst.
  • FIG. 4 is a cross-sectional view of a surface part of a catalyst carrier of an SOx trap.
  • FIGS. 5(A) to (C) are views for explaining NOx release control of an exhaust purification system of a first embodiment.
  • FIGS. 6(A) to (C) is a view for explaining NOx release control of an exhaust purification system of a second embodiment.
  • FIG. 7 is a view showing an example of a routine for executing NOx release control of an embodiment of the present invention.
  • FIGS. 8(A) to (C) are views for explaining the PM removal control of the exhaust purification system of a seventh embodiment.
  • FIGS. 9(A) to (C) are views for explaining the PM removal control of the exhaust purification system of an eighth embodiment.
  • FIG. 10 is a view showing an example of a routine for executing PM removal control of an embodiment of the present invention.
  • FIG. 11 is a view showing an example of a routine for executing NOx release control of an exhaust purification system of a 15th embodiment.
  • FIG. 12 is a view showing an example of a routine for executing PM removal control of an exhaust purification system of a 16th embodiment.
  • FIG. 13 is a view showing one of the compression ignition type of internal combustion engine to which the present invention can be applied.
  • FIG. 14 is a view showing another one of the compression ignition type of internal combustion engine to which the present invention can be applied.
  • FIG. 15 is a view showing still another one of the compression ignition type of internal combustion engine to which the present invention can be applied.
  • FIG. 1 shows a compression ignition type of internal combustion engine provided with an exhaust purification system of the present invention.
  • 1 shows an engine body, 2 a combustion chamber of each cylinder, 3 an electronic control type fuel injector for injecting fuel into each combustion chamber 2 , 4 an intake manifold, and 5 an exhaust manifold.
  • the intake manifold 4 is connected through an intake duct 6 to an outlet of a compressor 7 a of an exhaust turbocharger 7 , while an inlet of the compressor 7 a is connected to an air cleaner 8 .
  • a throttle valve 9 driven by a step motor.
  • a cooling device 10 for cooling the intake air flowing inside the intake duct 6 .
  • the engine cooling water is guided into the cooling device 10 where the engine cooling water is used to cool the intake air.
  • the exhaust manifold 5 is connected to the inlet of the exhaust turbine 7 b of the exhaust turbocharger 7 , while the outlet of the exhaust turbine 7 b is connected through an exhaust pipe 13 to the inlet of the SO x trap 11 .
  • the exhaust pipe 13 has attached to it an HC (hydrocarbon) feed valve 14 for feeding for example HC in the exhaust gas flowing through the inside of the exhaust pipe 13 .
  • the outlet of the SOx trap 11 is connected to the NOx catalyst 12 .
  • the exhaust manifold 5 and the intake manifold 4 are connected to each other through an exhaust gas recirculation (hereinafter referred to as the “EGR”) passage 15 .
  • EGR exhaust gas recirculation
  • an electronic control type EGR control valve 16 Inside the EGR passage 15 is arranged an electronic control type EGR control valve 16 .
  • a cooling device 17 for cooling the EGR gas flowing through the inside of the EGR passage 15 .
  • the engine cooling water is guided inside the cooling device 17 where the engine cooling water is used to cool the EGR gas.
  • each fuel injector 3 is connected through a fuel feed pipe 18 to a common rail 19 .
  • This common rail 19 is supplied inside it with fuel from an electronic control type variable discharge fuel pump 20 .
  • the fuel supplied to the inside of the common rail 19 is supplied through the fuel feed pipes 18 to the fuel injectors 3 .
  • An electronic control unit 30 is comprised of a digital computer which is provided with components connected with each other by a bi-directional bus 31 such as a ROM (read only memory) 32 , RAM (random access memory) 33 , CPU (microprocessor) 34 , input port 35 , and output port 36 .
  • the SO x trap 11 has a temperature sensor 21 attached to it so as to detect the temperature of the SO x trap 11
  • the NOx catalyst 12 has a temperature sensor 22 attached to it so as to detect the temperature of the NOx catalyst 12 .
  • the output signals of these temperature sensors 21 and 22 are input through the corresponding AD converters 37 to the input port 35 .
  • the NOx catalyst 12 has a pressure difference sensor 23 attached to it for detecting the pressure difference before and after the NOx catalyst 12 .
  • the output signal of this pressure difference sensor 23 is input through the corresponding AD converter 37 to the input port 35 .
  • An accelerator pedal 40 is connected to a load sensor 41 generating an output voltage proportional to the depression amount of the accelerator pedal 40 .
  • the output voltage of the load sensor 41 is input through the corresponding AD converter 37 to the input port 35 .
  • the input port 35 has a crank angle sensor 42 generating an output pulse every time the crankshaft rotates by for example 15° connected to it.
  • the output port 36 has the fuel injectors 3 , throttle valve 9 drive step motor, HC feed valve 14 , EGR control valve 16 , and fuel pump 20 connected to it through corresponding drive circuits 38 .
  • the NOx catalyst 12 is carried on a monolithic carrier of a three-dimensional mesh structure or a pellet-shaped carrier or is carried on a particulate filter forming a honeycomb structure (hereinafter referred to as “filter”). In this way, the NOx catalyst 12 can be carried on various carriers, but below the case of carrying the NOx catalyst 12 on a filter will be explained.
  • FIGS. 2(A) and (B) show the structure of the filter 12 a carrying the NOx catalyst 12 .
  • FIG. 2(A) shows a front view of the filter 12 a
  • FIG. 2(B) shows a side cross-sectional view of the filter 12 a .
  • the filter 12 a forms a honeycomb structure and is provided with a plurality of exhaust flow passages 60 , 61 extending in parallel with each other. These exhaust flow passages are comprised of exhaust gas inflow passages 60 with downstream ends closed by plugs 62 and exhaust gas outflow passages 61 with upstream ends closed by plugs 63 . Note that the hatched parts in FIG. 2(A) show the plugs 63 .
  • the exhaust gas inflow passages 60 and exhaust gas outflow passages 61 are alternately arranged via thin partition walls 64 .
  • the exhaust gas inflow passages 60 and exhaust gas outflow passages 61 are arranged so that each exhaust gas inflow passage 60 is surrounded by four exhaust gas outflow passages 61 and each exhaust gas outflow passage 61 is surrounded by four exhaust gas inflow passages 60 .
  • the filter 12 a is for example formed from a porous material such as cordierite. Therefore, the exhaust gas flowing into the exhaust gas inflow passage 60 , as shown by the arrows in FIG. 2(B) , passes through the surrounding partition walls 64 and flows out into the adjoining exhaust gas outflow passages 61 .
  • the peripheral walls of the exhaust gas inflow passages 60 and exhaust gas outflow passages 61 that is, the two side surfaces of the partition walls 64 and the inside walls of the fine holes in the partition walls 64 , carry, for example, a catalyst carrier comprised of alumina.
  • FIG. 3 schematically shows a cross-section of the surface part of this catalyst carrier 45 . As shown in FIG. 3 , on the surface of the catalyst carrier 45 , a precious metal catalyst 46 is carried diffused in it. Further, on the surface of the catalyst carrier 45 , a layer of an NOx adsorbent 47 is formed.
  • the precious metal catalyst 46 platinum (Pt) is used.
  • the ingredient forming the NOx adsorbent 47 for example, at least one ingredient selected from potassium (K), sodium (Na), cesium (Cs), or another such alkali metal, barium (Ba), calcium (Ca), or another such alkali earth, and lanthanum (La), yttrium (Y), or another such rare earth is used.
  • the NOx adsorbent 47 absorbs the NOx when the air-fuel ratio of the exhaust gas is leaner than even the stoichiometric air-fuel ratio and releases the absorbed NOx when the oxygen concentration in the exhaust gas falls in an “NO x absorption/release action”.
  • NO 2 is produced on the surface of the platinum 46 . So long as the NOx adsorption ability of the NOx adsorbent 47 is not saturated, the NO 2 is absorbed in the NOx adsorbent 47 and nitric acid ions (NO 3 ⁇ ) are produced.
  • the reaction proceeds in the opposite direction (NO 3 ⁇ ⁇ NO 2 ) and therefore the nitric acid ions (NO 3 ⁇ ) in the NOx adsorbent 47 are released in the form of NO 2 from the NOx adsorbent 47 .
  • the released NOx is reduced by the unburned HC and CO contained in the exhaust gas.
  • HC is supplied from the HC feed valve 14 so as to temporarily make the air-fuel ratio of the exhaust gas rich and thereby make the NOx be released from the NOx adsorbent 47 .
  • exhaust gas contains SO x (sulfur oxides), that is, SO 2 . If this SO 2 flows into the NOx catalyst 12 , this SO 2 is oxidized at the platinum 46 and becomes SO 3 . Next, this SO 3 is adsorbed in the NOx adsorbent 47 and, while bonding with the barium oxide (BaO), diffuses in the NOx adsorbent 47 in the form of sulfuric acid ions (SO 4 2 ⁇ ) to produce stable sulfate (BaSO 4 ).
  • the NOx adsorbent 47 has a strong basicity, so this sulfate (BaSO 4 ) is stable and hard to break down.
  • the sulfate (BaSO 4 ) With just making the air-fuel ratio of the exhaust gas rich, the sulfate (BaSO 4 ) will not break down and will remain as it is. Therefore, in the NOx adsorbent 47 , as time elapses, the sulfate (BaSO 4 ) increases. Therefore, along with the elapse of time, the NOx amount which can be absorbed by the NOx adsorbent 47 falls.
  • the NOx adsorbent 47 is made to release the SO x .
  • the NOx adsorbent 47 only releases a little SO x at a time. Therefore, to make the NOx adsorbent 47 release all of the absorbed SO x , the air-fuel ratio of the exhaust gas must be made rich over a long time and therefore there is the problem that a large amount of fuel or reducing agent becomes necessary. Further, the SO x released from the SO x adsorbent 47 is exhausted into the atmosphere. This is also not preferable.
  • an SO x trap 11 is arranged upstream of the NOx catalyst 12 .
  • This SO x trap 11 is used to trap the SO x contained in the exhaust gas and thereby prevent SO x from being sent into the NOx catalyst 12 .
  • this SO x trap 11 will be explained.
  • This SO x trap 11 is comprised of for example a honeycomb structure monolithic catalyst and has a large number of exhaust gas circulation holes extending straight in the axial direction of the SO x trap 11 .
  • the inner circumferential walls of the exhaust gas circulation holes carry a catalyst carrier comprised of for example alumina.
  • FIG. 4 schematically shows the cross-section of the surface part of the catalyst carrier 50 . As shown in FIG. 4 , on the surface of the catalyst carrier 50 , a coat layer 51 is formed and carries the precious metal catalyst 52 diffused on its surface.
  • the precious metal catalyst 52 platinum (Pt) is used.
  • Pt platinum
  • the ingredient forming the coat layer 51 for example at least one element selected from potassium (K), sodium (Na), cesium (Cs), or another such alkali metal, barium (Ba), calcium (Ca), or another such alkali earth, and lanthanum (La), yttrium (Y), or another such rare earth is used. That is, the coat layer 51 of the SOx trap 11 exhibits a strong basicity.
  • the SOx contained in the exhaust gas mainly SO 2
  • the platinum 52 is oxidized on the platinum 52 , then is trapped in the coat layer 51 . That is, the SO 2 diffuses in the coat layer 51 in the form of sulfuric acid ions (SO 4 2 ⁇ ) and forms a sulfate. Note that in the above-mentioned way, the coat layer 51 exhibits a strong basicity. Therefore, as shown in FIG. 4 , part of the SO 2 contained in the exhaust gas is directly trapped in the coat layer 51 .
  • exhaust gas also contains particulate matter.
  • the particulate matter contained in exhaust gas is trapped on the filter 12 a carrying the NOx catalyst 12 and successively oxidized. However, if the amount of the trapped particulate matter becomes greater than the amount of the particulate matter oxidized, the particulate matter gradually deposits on the filter 12 a . In this case, if the amount of buildup of the particulate matter increases, a drop in the engine output ends up being invited. Therefore, when the amount of buildup of the particulate matter increases, the builtup particulate matter must be removed. In this case, if raising the temperature of the filter 12 a to 600° C. or so under an excess of air, the builtup particulate matter is oxidized and removed.
  • the temperature of the filter 12 a is raised under a lean air-fuel ratio of the exhaust gas and thereby the builtup particulate matter is oxidized and removed.
  • a pressure difference before and after the filter 12 a detected by a differential pressure sensor 23 exceeds an allowable value, it is judged that the amount of the builtup particulate matter has exceeded the allowable amount.
  • temperature elevation control is performed for raising the temperature of the filter 12 a while keeping the air-fuel ratio of the exhaust gas flowing into the filter 12 a lean.
  • the SOx trapping action of the above-mentioned SOx trap 11 is performed when the air-fuel ratio of the exhaust gas flowing into it is an air-fuel ratio leaner than the stoichiometric air-fuel ratio and the temperature of the SOx trap 11 is higher than a certain constant temperature (hereinafter referred to as the “activation temperature”).
  • the SOx trap 11 ends up releasing the trapped SOx when the air-fuel ratio of the exhaust gas flowing into it becomes the stoichiometric air-fuel ratio or richer and its temperature becomes higher than a certain constant temperature higher than the activation temperature (hereinafter referred to as the “SOx release temperature”).
  • SOx trap amount the amount of SOx being trapped in the SOx trap 11 (hereinafter referred to as “SOx trap amount”) becomes relatively large and exhaust gas of the stoichiometric air-fuel ratio or a richer air-fuel ratio flows into the SOx trap 11 , so there is a possibility of part of the SOx trap where the temperature locally becomes higher than the SOx release temperature releasing SOx. Further, even if the air-fuel ratio of the exhaust gas flowing into the SOx trap 11 becomes lean overall, sometimes it locally becomes rich.
  • the SOx trap amount of the SOx trap 11 becomes relatively large and the temperature of the SOx trap 11 becomes higher than the SOx release temperature, there is a possibility that part of the SOx trap 11 will release SOx. That is, to reliably prevent SOx from being released from the SOx trap 11 , when the SOx trap amount of the SOx trap 11 becomes relatively large and the air-fuel ratio of the exhaust gas flowing into the SOx trap 11 becomes the stoichiometric air-fuel ratio or richer or when it is estimated it will become the stoichiometric air-fuel ratio or richer, it is necessary to prevent the temperature of the SOx trap 11 from becoming higher than the SOx release temperature even locally.
  • the NOx release control for making the NOx absorbent 47 release NOx when the SOx trap amount of the SOx trap 11 is smaller than a predetermined amount (hereinafter referred to as “the predetermined amount”), just NOx release control for making the NOx absorbent 47 release NOx (hereinafter referred to as “ordinary NOx release control”) is executed, while when the SOx trap amount of the SOx trap 11 is larger than the predetermined amount, SOx release suppression/NOx release control for keeping the SOx trap 11 from releasing SOx while making the NOx absorbent 47 release NOx is executed.
  • the predetermined amount a predetermined amount
  • the SOx release suppression/NOx release control for keeping the SOx trap 11 from releasing SOx while making the NOx absorbent 47 release NOx
  • HC feed the feed of HC from the HC feed valve 14 into the exhaust gas
  • HC feed rate the amount of HC fed from the HC feed valve 14 into the exhaust gas per unit time in each HC feed
  • HC feed time the time during which the HC is fed from the HC feed valve 14 into the exhaust gas in one HC feed
  • HC feed interval the time interval at which each HC feed is performed
  • HC feed frequency the frequency by which HC feed is performed in one ordinary NOx release control or SOx release suppression/NOx release control
  • the ordinary NOx release control of the first embodiment is performed when it is judged that the NOx absorbent 47 should release NOx and when the SOx trap amount of the SOx trap 11 is smaller than the predetermined amount.
  • HC feed with an HC feed rate of a predetermined HC feed rate (hereinafter referred to as an “ordinary HC feed rate”) Qa and with an HC feed time of a predetermined HC feed time (hereinafter referred to as an “ordinary HC feed time”) Ta is performed at a predetermined HC feed interval (hereinafter referred to as the “ordinary HC feed interval”) Ia by a predetermined HC feed frequency (hereinafter referred to as an “ordinary HC feed frequency”, in the example shown in FIG. 5(A) , three times).
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are set so that the total amount of HC fed to the NOx catalyst 12 when all of the HC feed operations end becomes a sufficient HC amount for making the NOx absorbent 47 release a predetermined amount of NOx (hereinafter referred to as the “predetermined HC amount”). Therefore, according to the ordinary NOx release control of the first embodiment, it is possible to make the NOx absorbent 47 release a predetermined amount of NOx.
  • the SOx release suppression/NOx release control of the first embodiment is performed when it is judged that the NOx absorbent 47 should release NOx and when the SOx trap amount of the SOx trap 11 becomes greater than the predetermined amount.
  • HC feed with an HC feed rate of the HC feed rate Qb smaller than the ordinary HC feed rate Qa and with an HC feed time of a time Ta equal to the ordinary HC feed time Ta is performed at an interval Ib shorter than the ordinary HC feed interval Ia by a frequency larger than the ordinary HC feed frequency.
  • the amount of HC fed from the HC feed valve 14 into the exhaust gas is small, so the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. For this reason, formation of a region in the exhaust gas where the air-fuel ratio locally very rich is suppressed, so the temperature of the SOx trap 11 is kept from becoming higher than the locally SOx release temperature. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • the HC deposits to a partial region of the SOx trap 11 when the exhaust gas flows into the SOx trap 11 . If the deposited HC is burned all at once in that partial region of the SOx trap 11 , there is a possibility that the temperature of that partial region will become higher than the SOx release temperature.
  • the SOx release suppression/NOx release control of the first embodiment formation of a region in the exhaust gas where the air-fuel ratio locally becomes very rich is suppressed, so the temperature of the partial region of the SOx trap 11 is kept from becoming higher than the SOx release temperature. Therefore, the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature and the SOx trap 11 is reliably kept from releasing SOx.
  • HC feed with an HC feed rate of an HC feed rate Qb smaller than the ordinary HC feed rate Qa and with an HC feed time of a time Tc longer than the ordinary HC feed time may be performed at an interval Ic longer than the ordinary HC feed interval Ia by the same frequency as the ordinary HC feed frequency.
  • the HC feed rate in each HC feed operation is small, so the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. For this reason, the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature, so the SOx trap 11 is reliably kept from releasing SOx.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are set so that the total amount of HC fed to the NOx catalyst 12 when all of the HC feed operations end becomes the predetermined HC amount.
  • the HC feed rate is made the HC feed rate Qb of half of the ordinary HC feed rate Qa
  • the HC feed time is made the time Ta equal to the ordinary HC feed time Ta
  • the HC feed frequency is made a frequency double the ordinary HC feed frequency.
  • the HC feed interval is made an interval Ib of half of the ordinary HC feed interval Ia.
  • the HC feed rate is made the HC feed rate Qb of half of the ordinary HC feed rate Qa
  • the HC feed time is made the time Tc of double the ordinary HC feed time Ta
  • the HC feed frequency is made the same frequency as the ordinary HC feed frequency.
  • FIGS. 6(A) to (C) the upper line shows the feed of HC from the HC feed valve 14 into the exhaust gas, while the lower line shows the injection of fuel from the fuel injector 3 in the latter half of the expansion stroke or during an exhaust stroke of a specific cylinder.
  • the injection of fuel from the fuel injector 2 in the latter half of the expansion stroke or during the exhaust stroke of a specific cylinder will be referred to as the “post fuel injection”
  • the amount of fuel injected from the fuel injector 2 per unit time in each post fuel injection will be referred to as the “post fuel injection rate”
  • the time during which fuel is injected from the fuel injector 2 in one post fuel injection will be referred to as the “post fuel injection time”
  • the time interval at which each post fuel injection is performed will be referred to as the “post fuel injection interval”
  • the frequency one post fuel injection is performed will be referred to as the “post fuel injection frequency”.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are set so that the total amount of HC fed to the NOx catalyst 12 when all of the HC feed operations end becomes the predetermined HC amount.
  • SOx release suppression/NOx release control when the NOx release condition stands and the SOx trap amount of the SOx trap 11 is larger than the predetermined amount (that is, when the SOx release suppression condition stands), SOx release suppression/NOx release control is executed.
  • SOx release suppression/NOx release control as shown by the upper line of FIG. 6(B) , HC feed with an HC feed rate of an HC feed rate Qb smaller than the ordinary HC feed rate Qa and with an HC feed time of a time Ta equal to the ordinary feed time is performed at an interval Ia equal to the ordinary HC feed interval Ia by the same frequency as the ordinary frequency and, as shown by the lower line of FIG.
  • post fuel injection with a post fuel injection rate of a post fuel injection rate Qbp smaller than the ordinary HC feed rate Qa and with a post fuel injection time of a time Tap equal to the ordinary HC feed time Ta is performed at an interval Iap equal to the ordinary HC feed interval Ia by the same frequency as the ordinary HC feed frequency.
  • the fuel injected from the fuel injector 3 at a specific cylinder in the latter half of the expansion stroke or during the exhaust stroke is modified by the heat in the cylinder and lightened.
  • the thus lightened fuel passes through the SOx trap 11 and is fed to the NOx catalyst 12 , but this lightened fuel easily diffuses in the exhaust gas.
  • the fuel injected from the fuel injector 3 at a specific cylinder in the latter half of the expansion stroke or during the exhaust stroke is kept from causing the temperature of the SOx trap 11 from locally becoming higher than the SOx release temperature. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • HC is not fed from the HC feed valve 14 into the exhaust gas.
  • the fuel (HC) passing through the SOx trap 11 and fed to the NOx catalyst 12 is lightened fuel, so easily diffuses in the exhaust gas.
  • the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency and the post fuel injection rate at each post fuel injection, the post fuel injection time at each post fuel injection, and the post fuel injection frequency are preferably set so that the total amount of HC (fuel) fed to the NOx catalyst 12 when all of the HC feed operations and all of the post fuel injections end becomes the predetermined HC (fuel) amount.
  • the HC feed rate is made an HC feed rate Qb of half of the ordinary HC feed rate Qa
  • the HC feed time is made a time Ta equal to the ordinary HC feed time Ta
  • the HC feed frequency is made a frequency equal to the ordinary HC feed frequency
  • the post fuel injection rate is made a post fuel injection rate Qbp of half of the ordinary HC feed rate Qa
  • the post injection time is made a time Tap equal to the ordinary HC feed time Ta
  • the post fuel injection frequency is made a frequency equal to the ordinary HC feed frequency.
  • the HC feed interval and the post fuel injection interval are made intervals Ia, Iap equal to the ordinary HC feed interval Ia.
  • the post fuel injection rate is made a post fuel injection rate Qap equal to the ordinary HC feed rate Qa
  • the post fuel injection time is made a time Tap equal to the ordinary HC feed time Ta
  • the post fuel injection frequency is made a frequency equal to the ordinary HC feed frequency.
  • the post fuel injection interval is made an interval Iap equal to the ordinary HC feed interval Ia.
  • the post fuel injection is shown executed at the same timing as the HC feed, but the post fuel injection timing is controlled based on the crank angle of the internal combustion engine, so strictly speaking, in most cases, the post fuel injection timing will not become the same timing as the HC feed timing, but will deviate from it somewhat.
  • the post fuel injection interval was explained as equal to the ordinary HC feed interval, but for the same reason, strictly speaking, in most cases, the post fuel injection interval will not become equal to the ordinary HC feed interval, but will deviate from it somewhat.
  • the HC fed to the NOx catalyst when performing the post fuel injection in the latter half of the expansion stroke has a higher diffusion ability in the exhaust gas compared with HC fed to the NOx catalyst 12 when performing the post fuel injection during the exhaust stroke.
  • NOx release control only post fuel injection is employed as the method of feeding HC to the NOx catalyst 12 .
  • post fuel injection is performed during the exhaust stroke to feed HC to the NOx catalyst 12 .
  • SOx release suppression/NOx release control it is also possible to feed HC to the NOx catalyst 12 by performing post fuel injection in the latter half of the expansion stroke. This also enables the SOx trap 11 to be reliably kept from releasing SOx.
  • NOx release control of an exhaust purification system of a third embodiment will be explained.
  • control the same as the ordinary NOx release control of the first embodiment is executed.
  • NOx release control of the third embodiment when the NOx release condition stands and the SOx release suppression condition stands, SOx release suppression/NOx release control is executed.
  • this SOx release suppression/NOx release control in the same way as the ordinary NOx release control of the above-mentioned first embodiment, the ordinary HC feed rate, ordinary HC feed time, and, ordinary HC feed interval are used for performing each HC feed by an ordinary HC feed frequency, but HC lightened by fractional distillation is prepared in advance and part of the HC fed from the HC feed valve 14 into the exhaust gas in each HC feed is made this lightened HC. As explained above, lightened HC easily diffuses in the exhaust gas. For this reason, according to the SOx release suppression/NOx release control of the third embodiment, the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • NOx release control of an exhaust purification system of a fourth embodiment will be explained.
  • NOx release control of the fourth embodiment when the NOx release condition stands and the SOx release suppression condition does not stand, control the same as the ordinary NOx release control of the first embodiment is executed.
  • the NOx release control of the fourth embodiment when the NOx release condition stands and the SOx release suppression condition stands, SOx release suppression/NOx release control is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the temperature of the NOx catalyst 12 is kept lower than the temperature of the NOx catalyst 12 corresponding to the temperature of the SOx trap 11 at which the HC in the exhaust gas will end up burning all at once in the SOx trap 11 (hereinafter referred to as the “maximum NOx catalyst temperature”).
  • the temperature of the SOx trap 11 becomes higher than the temperature at which the HC flowing into it ends up being made to burn all at once.
  • the temperature of the SOx trap 11 will locally become higher than the SOx release temperature, and the SOx trap 11 will release SOx.
  • the temperature of the NOx catalyst 12 is kept lower than the maximum NOx catalyst temperature, so the HC flowing into the SOx trap 11 is kept from burning all at once. For this reason, the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed into the NOx catalyst 12 when all of the HC feed operations end becomes the predetermined amount.
  • NOx release control of an exhaust purification system of a fifth embodiment will be explained.
  • NOx release control of the fifth embodiment when the NOx release condition stands and the SOx release suppression condition does not stand, control the same as the ordinary NOx release control of the first embodiment is executed.
  • the NOx release control of the fifth embodiment when the NOx release condition stands and the SOx release suppression condition stands, SOx release suppression/NOx release control is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the amplitude of the rise and fall of the temperature of the NOx catalyst 12 (hereinafter referred to as “temperature amplitude”) is kept smaller than the temperature amplitude of the NOx catalyst 12 allowed in ordinary NOx release control. That is, in SOx release suppression/NOx release control, HC feed is intermittently performed, so the NOx catalyst 12 is intermittently fed HC.
  • the heat of reaction of the HC in the NOx catalyst 12 causes the temperature of the NOx catalyst 12 to rise, then fall.
  • the temperature amplitude of the NOx catalyst 12 being large means the amplitude of the rise or fall of the temperature of the SOx trap 11 is also large.
  • the temperature of the SOx trap 11 may at least locally become higher than the SOx release temperature.
  • the SOx trap amount of the SOx trap 11 is greater than the predetermined amount, the SOx trap 11 may release SOx.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the temperature amplitude of the NOx catalyst 12 is kept smaller than the temperature amplitude of the NOx catalyst 12 allowed in ordinary NOx release control. According to this, the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed into the NOx catalyst 12 when all of the HC feed operations end becomes the predetermined amount.
  • NOx release control of the exhaust purification system of a sixth embodiment will be explained.
  • NOx release control of the sixth embodiment when the NOx release condition stands and the SOx release suppression condition does not stand, control the same as the ordinary NOx release control of the above-mentioned first embodiment is executed.
  • the SOx release suppression/NOx release control when the NOx release condition stands and the SOx release suppression condition stands, the SOx release suppression/NOx release control is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the rich degree of the air-fuel ratio of the exhaust gas fed into the NOx catalyst 12 is kept smaller than the target rich degree in ordinary NOx release control. That is, when the rich degree of the air-fuel ratio of the exhaust gas flowing into the NOx catalyst 12 is large, the rich degree of the air-fuel ratio of the exhaust gas flowing into the SOx trap 11 also becomes large.
  • a region in the exhaust gas flowing into the SOx trap 11 where the air-fuel ratio locally becomes very rich may be formed.
  • formation of a region in the exhaust gas flowing into the SOx trap 11 where the air-fuel ratio locally becomes very rich is suppressed. For this reason, the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • the rich degree of the air-fuel ratio of the exhaust gas fed into the NOx catalyst 12 is for example estimated from the output of an air-fuel ratio sensor provided in the exhaust pipe downstream of the NOx catalyst 12 .
  • the HC flowing into the SOx trap 11 deposits at a partial region of the SOx trap 11 .
  • the temperature of the region of the SOx trap 11 where the HC deposits is low, the deposited HC will not burn but will remain deposited there.
  • the temperature of the region of the SOx trap 11 where HC has deposited rises to the combustion temperature of HC, the deposited HC may burn all at once. That is, the lower the temperature of the SOx trap 11 , the more possible it is that the HC deposited on the SOx trap 11 will burn all at once.
  • FIG. 7 shows an example of the routine for executing the NOx release control of an embodiment of the present invention.
  • the routine of FIG. 7 first, at step 10 , it is judged if the NOx amount ⁇ NOX absorbed in the NOx absorbent 47 is greater than an allowable value ⁇ ( ⁇ NOX> ⁇ ) (that is, whether the NOx release condition stands).
  • ⁇ NOX> ⁇ an allowable value
  • the routine is ended as is.
  • the routine proceeds to step 11 where it is judged if the SOx trap amount ⁇ SOX of the SOx trap 11 is greater than a predetermined amount ⁇ ( ⁇ SOX> ⁇ ) (that is, whether the SOx release suppression condition stands).
  • step 11 When it is judged at step 11 that ⁇ SOX> ⁇ , the routine proceeds to step 12 where one of the SOx release suppression/NOx release control of the above-mentioned first embodiment to sixth embodiment is executed. On the other hand, when it is judged at step 11 that ⁇ SOX ⁇ , the routine proceeds to step 13 where one of the ordinary NOx release control of the above-mentioned first embodiment to sixth embodiment is executed.
  • control is executed for keeping the air-fuel ratio of the exhaust gas flowing into the filter 12 a lean while raising the temperature of the filter 12 a to a temperature of at least the temperature where the particulate matter burns (hereinafter referred to as “PM combustion temperature”) to burn off the particulate matter deposited on the filter 12 a (hereinafter referred to as “PM removal control”).
  • PM combustion temperature a temperature of at least the temperature where the particulate matter burns
  • HC is fed from the HC feed valve 14 into the exhaust gas in a range where the air-fuel ratio of the exhaust gas flowing into the filter 12 a is kept lean. That is, if the HC feed valve 14 feeds HC into the exhaust gas, HC is fed to the filter 12 a . At this time, if the air-fuel ratio of the exhaust gas flowing into the filter 12 a is kept lean, the HC burns on the filter 12 a . The heat of combustion generated at that time causes the temperature of the filter 12 a to rise.
  • the temperature of the SOx trap 11 also becomes a relatively high temperature. For this reason, during execution of PM removal control, the temperature of the SOx trap 11 can be said to easily locally become higher than the SOx release temperature.
  • the SOx trap amount of the SOx trap 11 when the SOx trap amount of the SOx trap 11 is relatively large, it is necessary to suppress the formation of a region in the exhaust gas flowing into the SOx trap 11 where the air-fuel ratio locally forms a rich region or to keep the temperature of the SOx trap 11 from locally becoming higher than the SOx release temperature.
  • the PM removal control for removing the particulate matter built up on the filter 12 a when the SOx trap amount of the SOx trap 11 is smaller than the predetermined amount, just PM removal control for burning off the particulate matter built up on the filter 12 a (hereinafter referred to as “ordinary PM removal control”) is executed.
  • PM removal control for keeping the SOx trap 11 from releasing SOx while burning off the particulate matter built up on the filter 12 a hereinafter referred to as “SOx release suppression/PM removal control” is executed.
  • HC feed with an HC feed rate of a predetermined HC feed rate (hereinafter referred to as “ordinary HC feed rate”) Qd and with an HC feed time of a predetermined HC feed time (hereinafter referred to as “ordinary HC feed time”) Td is performed at a predetermined HC feed interval (hereinafter referred to as “ordinary HC feed interval”) Id by a predetermined HC feed frequency (hereinafter referred to as “ordinary HC feed frequency”, in the example shown in FIG. 8(A) , three times).
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are set so as to raise the temperature of the filter 12 a to the PM combustion temperature and so that the total amount of HC fed to the filter 12 a when all of the HC feed operations end becomes an HC amount sufficient for burning off exactly a predetermined amount of the particulate matter built up on the filter 12 a (hereinafter referred to as “the predetermined HC amount”). Therefore, according to the ordinary PM removal control of the seventh embodiment, it is possible to burn off exactly a predetermined amount of the particulate matter built up on the filter 12 a.
  • SOx release suppression/PM removal control when the PM removal condition stands and the SOx trap amount of the SOx trap 11 is larger than the predetermined amount (that is, when the SOx release suppression condition stands), SOx release suppression/PM removal control is executed.
  • HC feed with a HC feed rate of an HC feed rate Qe smaller than the ordinary HC feed rate Qd and with an HC feed time of a time Td equal to the ordinary HC feed time Td is performed at an interval Ie shorter than the ordinary HC feed interval Id by a frequency greater than the ordinary HC feed frequency.
  • the amount of HC fed from the HC feed valve 14 into the exhaust gas in one HC feed is small, so the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. For this reason, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed; so the release of SOx from the SOx trap 11 is reliably suppressed.
  • an HC feed with an HC feed rate of an HC feed rate Qe smaller than the ordinary HC feed rate Qd and with an HC feed time of a time Tf longer than the ordinary HC feed time may also be performed at an interval If longer than the ordinary HC feed interval Id by the same frequency as the ordinary HC feed frequency.
  • the HC feed rate in each HC feed is small, so the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. For this reason, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is reliably suppressed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, the HC feed interval, and the HC feed frequency are set to at least enable the temperature of the filter 12 a to be raised to the PM combustion temperature.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed to the filter 12 a when all of the HC feed operations end becomes the predetermined amount.
  • the HC feed rate is made the HC feed rate Qe of half of the ordinary HC feed rate Qd
  • the HC feed time is made a time Td equal to the ordinary HC feed time Td
  • the HC feed frequency is made a frequency twice the ordinary HC feed frequency.
  • the HC feed interval is made an interval Ie of half of the ordinary HC feed intervals Id.
  • the HC feed rate is made an HC feed rate Qe of half of the ordinary HC feed rate Qd
  • the HC feed time is made a time Tf of double the ordinary HC feed time Td
  • the HC feed frequency is made a frequency equal to the ordinary HC feed frequency so that the total amount of HC fed to the filter 12 a when all of the HC feed operations end becomes the predetermined amount.
  • the HC feed interval is made an interval of about 1.5 times the ordinary HC feed interval.
  • the PM removal control of the exhaust purification system of an eighth embodiment will be explained with reference to FIG. 9 .
  • the upper line shows the feed of HC from the HC feed valve 14 into the exhaust gas
  • the lower line shows the injection of fuel from the fuel injector 3 at a specific cylinder in the latter half of the expansion stroke or during the exhaust stroke.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are set so as to raise the temperature of the filter 12 a to the PM combustion temperature and so that the total amount of HC fed to the filter 12 a when all of the HC feed operations end becomes the predetermined amount.
  • post fuel injection with a post fuel injection rate of a post fuel injection rate Qep smaller than the ordinary HC feed rate Qd and with a post fuel injection time of a time Tdp equal to the ordinary HC feed time Td is performed at an interval Idp equal to the ordinary HC feed interval Id by a frequency the same as the ordinary HC feed frequency.
  • the fuel injected from the fuel injector 3 at a specific cylinder in the latter half of the expansion stroke or during the exhaust stroke is modified by the heat in the cylinder and lightened. Further, this lightened fuel easily diffuses in the exhaust gas. For this reason, the fuel injected from the fuel injector 3 at a specific cylinder in the latter half of the expansion stroke or during the exhaust stroke is kept from causing the formation of a region in the exhaust gas where the air-fuel ratio locally becomes very rich. Therefore, the SOx trap 11 is reliably kept from releasing SOx.
  • the HC feed valve 14 does not feed HC into the exhaust gas. According to this, the fuel (HC) passing through the SOx trap 11 and fed to the filter 12 a is lightened fuel, so easily diffuses in the exhaust gas. For this reason, formation of a region in the exhaust gas where the air-fuel ratio locally becomes very rich is suppressed, so the SOx trap 11 is reliably kept from releasing SOx.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, the HC feed interval, and the HC feed frequency are set so as to at least enable the temperature of the filter 12 a to be raised to the PM combustion temperature.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency and the post fuel injection rate in each post fuel injection, the post fuel injection time in each post fuel injection, and the post fuel injection frequency are preferably set so that the total amount of HC (fuel) fed to the filter 12 a when all of the HC feed operations and all of the post fuel injections end becomes the predetermined HC (fuel).
  • the HC feed rate is made an HC feed rate Qe of half of the ordinary HC feed rate Qd
  • the HC feed time is made a time Td equal to the ordinary HC feed time Td
  • the HC feed frequency is made a frequency equal to the ordinary HC feed frequency
  • the post fuel injection rate is made a post fuel injection rate Qdp of half of the ordinary HC feed rate Qd
  • the post injection time is made a time Tdp equal to the ordinary HC feed time Td
  • the post fuel injection frequency is made a frequency equal to the ordinary HC feed frequency.
  • the HC feed interval and the post fuel injection intervals are both made intervals Id, Idp equal to the ordinary HC feed interval Id.
  • the post fuel injection rate is made a post fuel injection rate Tdp equal to the ordinary HC feed rate Qd
  • the post fuel injection time is made a time Tdp equal to the ordinary HC feed time Td
  • the post fuel injection frequency is made a frequency equal to the ordinary HC feed frequency so that the total amount of HC (fuel) fed to the filter 12 a when all of the HC feed operations and all of the post fuel injections end becomes the predetermined HC (fuel).
  • the post fuel injection interval is made an interval Tdp equal to the ordinary HC feed interval Id.
  • the post fuel injection is shown executed at the same timing as the HC feed, but the post fuel injection timing is controlled based on the crank angle of the internal combustion engine, so strictly speaking, in most cases, the post fuel injection timing will not become the same timing as the HC feed timing, but will deviate from it somewhat.
  • the post fuel injection interval was explained as equal to the ordinary HC feed interval, but for the same reason, strictly speaking, in most cases, the post fuel injection interval will not become equal to the ordinary HC feed interval, but will deviate from it somewhat.
  • PM removal control of an exhaust purification system of a ninth embodiment will be explained.
  • the same control as the ordinary PM removal control of the seventh embodiment is executed.
  • the PM removal control of the ninth embodiment when the PM removal condition stands and the SOx release suppression condition stands, SOx release suppression/PM removal control is executed.
  • the ordinary HC feed rate, ordinary HC feed time, and ordinary HC feed interval are used for performing each HC feed by the ordinary HC feed frequency, but HC lightened by fractional distillation is prepared in advance and, in each HC feed, part of the HC fed from the HC feed valve 14 into the exhaust gas is made this lightened HC.
  • the lightened HC easily diffuses in the exhaust gas. For this reason, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is reliably suppressed.
  • the SOx release suppression/PM removal control when the PM removal condition stands and the SOx release suppression condition stands, the SOx release suppression/PM removal control is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the temperature of the SOx trap 11 is kept lower than the temperature where the HC in the exhaust gas ends up being burned all at once at the SOx trap 11 .
  • the HC is kept from burning all at once at the SOx trap 11 . For this reason, the temperature of the SOx trap 11 is kept from locally becoming higher than the SOx release temperature, so the SOx trap 11 is reliably kept from releasing SOx.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, the HC feed interval, and the HC feed frequency are set so as to at least enable the temperature of the filter 12 a to be raised to the PM combustion temperature.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed to the filter 12 a becomes the predetermined amount when all of the HC feed operations end.
  • the PM removal control of the 11th embodiment when the PM removal condition stands and the SOx release suppression condition stands, SOx release suppression/PM removal control is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the temperature of the filter 12 a is kept at a temperature as close as possible to the PM combustion temperature.
  • the HC feed rate at one HC feed is set small, the HC feed time in one HC feed is set short, or the HC feed interval is set long. Therefore, the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. For this reason, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is reliably suppressed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, the HC feed interval, and the HC feed frequency are set so as to at least enable the temperature of the filter 12 a to be raised to the PM combustion temperature.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed to the filter 12 a becomes the predetermined amount when all of the HC feed operations end.
  • the time during which the SOx release suppression/PM removal control is executed becomes longer than the time during which ordinary PM removal control is executed.
  • PM removal control of an exhaust purification system of a 12th embodiment will be explained.
  • the same control as the ordinary PM removal control of the seventh embodiment is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the width of the rise or fall of the temperature of the SOx trap 11 (hereinafter referred to as the “temperature amplitude”) is kept smaller than the temperature amplitude of the SOx trap 11 allowed in ordinary PM removal control.
  • the HC feed rate in each HC feed is set smaller, the HC feed time in each HC feed is set shorter, or the HC feed interval is set longer.
  • the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. Therefore, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is reliably suppressed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are set to enable at least the temperature of the filter 12 a to be raised to the PM combustion temperature.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed to the filter 12 a when all of the HC feeds end becomes a predetermined HC amount.
  • the SOx release suppression/PM removal control when the PM removal condition stands and the SOx release suppression condition stands, the SOx release suppression/PM removal control is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the lean degree of the air-fuel ratio of the exhaust gas fed to the filter 12 a is kept larger than the target lean degree in the ordinary PM removal control. That is, when the lean degree of the air-fuel ratio of the exhaust gas flowing into the filter 12 a is small, the lean degree of air-fuel ratio of the exhaust gas flowing into the SOx trap 11 also becomes small.
  • a region in the exhaust gas flowing into the SOx trap 11 where the air-fuel ratio locally becomes rich may be formed.
  • the formation of a region in the exhaust gas flowing into the SOx trap 11 where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is reliably suppressed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are set to enable at least the temperature of the filter 12 a to be raised to the PM combustion temperature.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed to the filter 12 a when all of the HC feeds end becomes a predetermined HC amount.
  • the lean degree of the air-fuel ratio of the exhaust gas fed to the filter 12 a is, for example, estimated from the output of the air-fuel ratio sensor attached to exhaust pipe downstream of the filter 12 a.
  • the PM removal control of the 14th embodiment when the PM removal condition stands and the SOx release suppression condition stands, SOx release suppression/PM removal control is executed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval are controlled so that the temperature elevation rate when the filter 12 a is raised in temperature is kept smaller than the target temperature elevation rate in ordinary PM removal control.
  • the HC feed rate in one HC feed is set smaller, the HC feed time in one HC feed is set shorter, or the HC feed interval is set longer.
  • the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. For this reason, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is reliably suppressed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, the HC feed interval, and the HC feed frequency are set so as to at least enable the temperature of the filter 12 a to be raised to the PM combustion temperature.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed frequency are preferably set so that the total amount of HC fed to the filter 12 a when all of the HC feed operations end becomes the predetermined amount.
  • FIG. 10 shows an example of a routine for executing the PM removal control of an embodiment of the present invention.
  • the routine of FIG. 10 first, at step 20 , it is judged if the amount ⁇ PM of particulate matter deposited on the filter 12 a is greater than an allowable value ⁇ ( ⁇ PM> ⁇ ) (that is, if the PM removal condition stands).
  • ⁇ PM> ⁇ an allowable value
  • the routine is ended as is.
  • the routine proceeds to step 21 where it is judged if the SOx trap amount ⁇ SOX of the SOx trap 11 is greater than a predetermined amount ⁇ ( ⁇ SOX> ⁇ ) (that is, whether the SOx release suppression condition stands).
  • step 21 When it is judged at step 21 that ⁇ SOX> ⁇ , the routine proceeds to step 22 where the SOx release suppression/PM removal control of one of the above-mentioned seventh embodiment to the 14th embodiment is executed. On the other hand, when it is judged at step 21 that ⁇ SOX ⁇ , the routine proceeds to step 23 where the SOx release suppression/PM removal control of one of the above-mentioned seventh embodiment to the 14th embodiment is executed.
  • the SOx trap 11 ends up releasing SOx.
  • NOx release control of an exhaust purification system of the 15th embodiment when trying to make the NOx absorbent 47 release NOx (that is, when the NOx release condition stands), it is possible to prohibit the feed of HC from the HC feed valve 14 into the exhaust gas (that is, the execution of NOx release control in the above-mentioned embodiment) if the temperature of the SOx trap 11 becomes higher than the SOx release temperature. According to this, the SOx trap 11 is reliably kept from releasing SOx.
  • FIG. 11 shows an example of a routine executing NOx release control of a 15th embodiment.
  • the routine of FIG. 11 first, at step 30 , it is judged if the NOx amount ⁇ NOX absorbed in the NOx absorbent 47 is greater than an allowable value ⁇ ( ⁇ NOX> ⁇ ) (that is, whether the NOx release condition stands).
  • ⁇ NOX> ⁇ an allowable value
  • the routine is ended as is.
  • the routine proceeds to step 31 where it is judged if the temperature Tsox of the SOx trap 11 is the SOx release temperature Tth or more (Tsox ⁇ Tth).
  • step 31 When it is judged at step 31 that Tsox ⁇ Tth, the routine proceeds to step 32 where execution of NOx release control is prohibited. That is, in this case, the NOx release control is not executed.
  • step 33 the routine proceeds to step 33 , where it is judged if the SOx trap amount ESOX of the SOx trap 11 is greater than a predetermined amount ⁇ ( ⁇ SOX> ⁇ ) (that is, whether the SOx release suppression condition stands).
  • step 33 When it is judged at step 33 that ⁇ SOX> ⁇ , the routine proceeds to step 34 , where SOx release suppression/NOx release control of one of the above-mentioned first embodiment to sixth embodiment is executed. On the other hand, when it is judged at step 33 that ⁇ SOX ⁇ , the routine proceeds to step 35 where one of the ordinary NOx release control of the above-mentioned first embodiment to sixth embodiment is executed.
  • the following control may also be employed. That is, as explained above, during execution of PM removal control, the temperature of the SOx trap 11 becomes relatively high, but here when the temperature of the SOx trap 11 is higher than the SOx release temperature, compared with when the temperature of the SOx trap 11 is lower than the SOx release temperature, the formation in the exhaust gas of a region where the air-fuel ratio locally becomes rich should be reliably suppressed.
  • the PM removal control of the 16th embodiment when the PM removal condition stands and the SOx release suppression condition does not stand, one of the SOx release suppression/PM removal control of the above-mentioned seventh embodiment to 14th embodiment is executed.
  • the PM removal control of the 16th embodiment when the PM removal condition stands and the SOx release suppression condition stands, it is judged that the temperature of the SOx trap 11 is higher than the SOx release temperature.
  • the temperature of the SOx trap 11 is lower than the SOx release temperature, either of the SOx release suppression/PM removal control of the above-mentioned seventh embodiment to the 14th embodiment is executed.
  • the HC feed rate at this time is made smaller than the HC feed rate in the SOx release suppression/PM removal control performed when the temperature of the SOx trap 11 is lower than the SOx release temperature. According to this, the amount of HC fed from the HC feed valve 14 in one HC feed is small, so the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. For this reason, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is suppressed.
  • the HC feed rate in each HC feed, the HC feed time in each HC feed, and the HC feed interval may be controlled so that the width of the rise or fall of the temperature of the SOx trap 11 (temperature amplitude) when the temperature of the SOx trap 11 is higher than the SOx release temperature is kept smaller than the temperature amplitude of the SOx trap 11 allowed in the SOx release/PM removal control performed when the temperature of the SOx trap 11 is lower than the SOx release temperature.
  • the HC feed rate in each HC feed is set smaller, the HC feed time in each HC feed is set shorter, or the HC feed interval is set longer. For this reason, the HC fed from the HC feed valve 14 easily diffuses in the exhaust gas. Therefore, the formation in the exhaust gas of a region where the air-fuel ratio becomes locally rich is suppressed, so the release of SOx from the SOx trap 11 is reliably suppressed.
  • FIG. 12 shows an example of the routine executing the PM removal control of the 16th embodiment.
  • the routine of FIG. 12 first, at step 40 , it is judged if the amount ⁇ PM of the particulate matter deposited on the filter 12 a is greater than an allowable value ⁇ ( ⁇ PM> ⁇ ) (that is, whether the PM removal condition stands).
  • ⁇ PM> ⁇ an allowable value
  • the routine is ended as is.
  • the routine proceeds to step 41 where it is judged if the SOx trap amount ⁇ SOX of the SOx trap 11 is greater than a predetermined amount ⁇ ( ⁇ SOX> ⁇ ) (that is, whether the SOx release suppression condition stands).
  • step 41 When it is judged at step 41 that ⁇ SOX ⁇ , the routine proceeds to step 45 where one of the ordinary PM removal control of the seventh embodiment to 14th embodiment is executed. On the other hand, when it is judged at step 41 that ⁇ SOX> ⁇ , the routine proceeds to step 42 where it is judged if the temperature Tsox of the SOx trap 11 is the SOx release temperature Tth or more (Tsox ⁇ Tth).
  • step 44 SOx release suppression/PM removal control II is executed.
  • SOx release suppression/PM removal control II one of the SOx release suppression/PM removal control of the seventh embodiment to the 14th embodiment is executed.
  • step 45 SOx release suppression/PM removal control I is executed.
  • control similar to the SOx release suppression/PM removal control II of step 44 is executed, but here the HC feed rate is made smaller than the HC feed rate at the SOx release suppression/PM removal control II of step 44 .
  • NOx release control of an exhaust purification system of a 17th embodiment it is also possible to employ the following control as NOx release control of an exhaust purification system of a 17th embodiment. That is, in the NOx release control of the 17th embodiment, when the lean degree of the air-fuel ratio of the exhaust gas exhausted from each cylinder is larger than a predetermined lean degree (hereinafter referred to as “the predetermined lean degree”), one of the ordinary NOx release control of the first embodiment to sixth embodiment is executed when the NOx release condition stands. On the other hand, when the lean degree of the air-fuel ratio of the exhaust gas exhausted from each cylinder is smaller than the predetermined lean degree, one of the SOx release suppression/NOx release control of the first embodiment to sixth embodiment is executed when the NOx release condition stands. According to this, the SOx trap 11 is reliably kept from releasing SOx.
  • the following control may be employed. That is, in the PM removal control of the 18th embodiment, when the lean degree of the air-fuel ratio of the exhaust gas exhausted from each cylinder is larger than a predetermined lean degree (hereinafter referred to as “the predetermined lean degree”), one of the ordinary PM removal control of the seventh embodiment to 14th embodiment is executed when the PM removal condition stands. On the other hand, when the lean degree of the air-fuel ratio of the exhaust gas exhausted from each cylinder is smaller than the predetermined lean degree, one of the SOx release suppression/PM removal control of the seventh embodiment to the 14th embodiment is executed when the PM removal condition stands. According to this, the SOx trap 11 is reliably kept from releasing SOx.
  • the NOx release control and PM removal control of the above-mentioned embodiments can also be applied to the compression ignition type of internal combustion engine shown in FIG. 13 .
  • the internal combustion engine shown in FIG. 13 is similar to the internal combustion engine shown in FIG. 1 , but in the internal combustion engine shown in FIG. 13 , instead of the NOx catalyst 12 carried on the filter 12 a , a particulate filter 12 a for trapping particulate matter is arranged downstream of the SOx trap 11 and an NOx catalyst 12 is arranged downstream of the particulate filter 12 a .
  • the NOx release control of the above-mentioned embodiments is adopted.
  • the PM removal control of above-mentioned embodiments is employed.
  • the particulate filter 12 a is provided with a temperature sensor 22 for detecting the temperature of the particulate filter 12 a and a differential pressure sensor 23 for detecting the differential pressure before and after the particulate filter 12 a .
  • the NOx catalyst 12 is provided with a temperature sensor 24 for detecting the temperature of the NOx catalyst 12 .
  • the NOx release control and PM removal control of the above-mentioned embodiments may also be applied to the compression ignition type of internal combustion engine shown in FIG. 14 .
  • the internal combustion engine shown in FIG. 14 is similar to the internal combustion engine shown in FIG. 1 , but in the internal combustion engine shown in FIG. 14 , downstream of the SOx trap 11 , instead of the NOx catalyst 12 carried on the filter 12 a , an NOx catalyst 12 is arranged and, downstream of the NOx catalyst 12 , just a particulate filter 12 a for trapping particulate matter is arranged. Further, in the internal combustion engine shown in FIG.
  • the NOx release control of the above-mentioned embodiments is employed. Further, in the internal combustion engine shown in FIG. 14 , when trying to burn off the particulate matter built up on the particulate filter 12 a , the PM removal control of the above-mentioned embodiments is employed.
  • FIG. 15 it is also possible to arrange upstream of the SOx trap 11 an oxidation catalyst 26 oxidizing the HC fed from the HC feed valve 14 into the exhaust gas and provided with an oxidizing ability higher than the oxidizing ability of the SOx trap 11 .
  • the HC fed from the HC feed valve 14 into the exhaust gas is oxidized by the oxidation catalyst 26 , so formation of a region in the exhaust gas where the air-fuel ratio locally becomes rich is reliably suppressed.
  • the HC feed valve 14 is provided with a heater for heating the HC feed valve 14 .
  • a heater for heating the HC feed valve 14 .
  • the HC feed valve 14 may be heated by the heater. According to this, in SOx release suppression/NOx release control or SOx release suppression/PM removal control, HC fed from the HC feed valve 14 easily diffuses in the exhaust gas, so SOx is kept from being released from the SOx trap 11 .
  • the pressure for feeding HC from the HC feed valve 14 into the exhaust gas may be made higher than the pressure for feeding HC from the HC feed valve 14 into the exhaust gas in ordinary NOx release control or ordinary PM removal control. Due to this as well, in SOx release suppression/NOx release control or SOx release suppression/PM removal control, the HC fed from the HC feed valve 14 becomes-able to easily diffuse in the exhaust gas, so SOx is kept from being released from the SOx trap 11 .
  • an HC feed valve provided with a plurality of feed ports for feeding HC and enabling the number of feed ports feeding HC to be suitably changed is employed.
  • the number of feed ports for feeding HC may be made greater than the number of feed ports feeding HC in ordinary NOx release control or ordinary PM removal control.
  • NOx release control methods of the plurality of the above-mentioned embodiments may be combined within a range not giving rise to any contradictions
  • PM removal control methods of the plurality of the above-mentioned embodiments may be combined within a range not giving rise to any contradictions.
  • the NOx release control or PM removal control of the embodiments other than the above-mentioned second embodiment, third embodiment, eighth embodiment, and ninth embodiment can be applied not only to an internal combustion engine feeding HC from the HC feed valve 14 into the exhaust gas, but also to an internal combustion engine injecting fuel from a fuel injector 3 in a latter half of an expansion stroke or during an exhaust stroke of a specific cylinder.

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US20150315950A1 (en) * 2012-12-07 2015-11-05 Toyota Jidosha Kabushiki Kaisha Abnormality detection device for exhaust gas purification apparatus
US9238200B2 (en) 2010-08-30 2016-01-19 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9458745B2 (en) 2010-03-15 2016-10-04 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
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Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103097680B (zh) * 2011-08-29 2015-03-11 丰田自动车株式会社 内燃机的排气净化装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6367246B1 (en) * 1997-04-24 2002-04-09 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification device for internal combustion engine
US20040020192A1 (en) * 2002-07-31 2004-02-05 Toyota Jidosha Kabushiki Kaisha Exhaust emission purification device for internal combustion engine
US6823658B2 (en) * 2001-08-28 2004-11-30 Honda Giken Kogyo Kabushiki Kaisha Exhaust gas purifying apparatus for an internal-combustion engine
US20050050881A1 (en) * 2003-05-14 2005-03-10 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification system for internal combustion engine
US20060010854A1 (en) * 2002-09-10 2006-01-19 Toyota Jidosha Kabushiki Kaisha Exhaust gas clarifying device for internal combustion engine
US20060064969A1 (en) * 2003-10-29 2006-03-30 Toyota Jidosha Kabushiki Kaisha Exhaust purification device of compression ignition type internal combustion engine

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2605559B2 (ja) 1992-12-03 1997-04-30 トヨタ自動車株式会社 内燃機関の排気浄化装置
JP3381489B2 (ja) * 1995-11-08 2003-02-24 トヨタ自動車株式会社 ディーゼル機関の排気ガス浄化触媒及び浄化装置
JP3582365B2 (ja) * 1998-07-03 2004-10-27 トヨタ自動車株式会社 内燃機関の排気浄化装置
DE10001432A1 (de) * 2000-01-15 2001-08-16 Volkswagen Ag Verfahren und Vorrichtung zur Steuerung einer Entschwefelung eines in einem Abgaskanal einer Verbrennungskraftmaschine angeordneten NO¶x¶-Speicherkatalysators
JP4083453B2 (ja) * 2002-03-29 2008-04-30 いすゞ自動車株式会社 ＮＯｘ浄化システム及びその触媒劣化回復方法
JP3867612B2 (ja) * 2002-04-12 2007-01-10 トヨタ自動車株式会社 内燃機関の空燃比制御装置
JP3972864B2 (ja) * 2003-06-04 2007-09-05 トヨタ自動車株式会社 内燃機関の排気浄化システム
JP4406309B2 (ja) * 2004-03-25 2010-01-27 トヨタ自動車株式会社 内燃機関の排気浄化装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6367246B1 (en) * 1997-04-24 2002-04-09 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification device for internal combustion engine
US6823658B2 (en) * 2001-08-28 2004-11-30 Honda Giken Kogyo Kabushiki Kaisha Exhaust gas purifying apparatus for an internal-combustion engine
US20040020192A1 (en) * 2002-07-31 2004-02-05 Toyota Jidosha Kabushiki Kaisha Exhaust emission purification device for internal combustion engine
US20060010854A1 (en) * 2002-09-10 2006-01-19 Toyota Jidosha Kabushiki Kaisha Exhaust gas clarifying device for internal combustion engine
US20050050881A1 (en) * 2003-05-14 2005-03-10 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification system for internal combustion engine
US20060064969A1 (en) * 2003-10-29 2006-03-30 Toyota Jidosha Kabushiki Kaisha Exhaust purification device of compression ignition type internal combustion engine
US7181904B2 (en) * 2003-10-29 2007-02-27 Toyota Jidosha Kabushiki Kaisha Exhaust purification device of compression ignition type internal combustion engine

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9623375B2 (en) 2010-03-15 2017-04-18 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9458745B2 (en) 2010-03-15 2016-10-04 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9032711B2 (en) 2010-04-01 2015-05-19 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9108153B2 (en) 2010-07-28 2015-08-18 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9238200B2 (en) 2010-08-30 2016-01-19 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9121325B2 (en) 2010-08-30 2015-09-01 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US8656706B2 (en) 2010-09-02 2014-02-25 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9038372B2 (en) 2010-10-04 2015-05-26 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9034267B2 (en) 2010-10-04 2015-05-19 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US20130195724A1 (en) * 2010-10-18 2013-08-01 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9010090B2 (en) * 2010-10-18 2015-04-21 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US20130216436A1 (en) * 2010-10-20 2013-08-22 Toyota Jidosha Kabushiki Kaisha Catalyst deterioration judging system
US9459242B2 (en) 2010-10-20 2016-10-04 Toyota Jidosha Kabushiki Kaisha Catalyst deterioration judging system
US9017614B2 (en) 2010-12-06 2015-04-28 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9108154B2 (en) 2010-12-20 2015-08-18 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9028761B2 (en) 2010-12-24 2015-05-12 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9109491B2 (en) 2011-02-07 2015-08-18 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9140162B2 (en) 2011-02-10 2015-09-22 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9010097B2 (en) 2011-03-17 2015-04-21 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9021788B2 (en) 2011-04-15 2015-05-05 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9034268B2 (en) 2011-11-07 2015-05-19 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9097157B2 (en) 2011-11-09 2015-08-04 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9028763B2 (en) 2011-11-30 2015-05-12 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9175590B2 (en) 2011-11-30 2015-11-03 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US9103259B2 (en) 2012-02-07 2015-08-11 Toyota Jidosha Kabushiki Kaisha Exhaust purification system of internal combustion engine
US20150315950A1 (en) * 2012-12-07 2015-11-05 Toyota Jidosha Kabushiki Kaisha Abnormality detection device for exhaust gas purification apparatus
US9879586B2 (en) * 2012-12-07 2018-01-30 Toyota Jidosha Kabushiki Kaisha Abnormality detection device for exhaust gas purification apparatus

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CN101484670A (zh) 2009-07-15
JP4404073B2 (ja) 2010-01-27
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WO2008001950A1 (fr) 2008-01-03
EP2039900A1 (fr) 2009-03-25

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