WO2015041292A1 - Diagnostic device - Google Patents

Diagnostic device Download PDF

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Publication number
WO2015041292A1
WO2015041292A1 PCT/JP2014/074690 JP2014074690W WO2015041292A1 WO 2015041292 A1 WO2015041292 A1 WO 2015041292A1 JP 2014074690 W JP2014074690 W JP 2014074690W WO 2015041292 A1 WO2015041292 A1 WO 2015041292A1
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Prior art keywords
dpf
doc
amount
heat
exhaust
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PCT/JP2014/074690
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French (fr)
Japanese (ja)
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英和 藤江
正 内山
哲史 塙
直人 村澤
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いすゞ自動車株式会社
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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
    • B01D53/96—Regeneration, reactivation or recycling of 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
    • B01D53/9459—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts
    • B01D53/9477—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts with catalysts positioned on separate bricks, e.g. exhaust systems
    • 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
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • 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
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/025—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using fuel burner or by adding fuel to exhaust
    • F01N3/0253—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using fuel burner or by adding fuel to exhaust adding fuel to exhaust gases
    • 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
    • F01N3/103—Oxidation catalysts for HC and CO only
    • 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
    • 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
    • F01N9/005—Electrical control of exhaust gas treating apparatus using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2067—Urea
    • 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
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20738—Iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/50—Zeolites
    • 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
    • F01N2900/1618—HC-slip from catalyst
    • 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
    • F01N2900/1621—Catalyst conversion efficiency
    • 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
    • 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
    • F02D41/024—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus
    • F02D41/025—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus by changing the composition of the exhaust gas, e.g. for exothermic reaction on exhaust gas treating apparatus
    • 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
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1446—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being exhaust temperatures
    • 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
    • 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 a diagnostic apparatus, and more particularly, to a deterioration diagnosis of an exhaust purification catalyst provided in an exhaust system of an internal combustion engine.
  • Oxidation catalyst Diesel Oxidation Catalyst: DOC
  • HC hydrocarbons
  • CO carbon monoxide
  • NO nitric oxide
  • a diesel particulate filter (DPF) that collects particulate matter (PM) contained in exhaust gas is also known.
  • the disclosed diagnostic device aims to perform a deterioration diagnosis of the catalytic function of the DPF with high accuracy.
  • the disclosed diagnostic apparatus includes an oxidation catalyst that is provided in an exhaust system of an internal combustion engine and that oxidizes at least hydrocarbons contained in exhaust gas, and is provided on the exhaust gas downstream side of the oxidation catalyst and is included in exhaust gas particles.
  • Filter for collecting substances supply means capable of supplying hydrocarbons to the oxidation catalyst, inlet exhaust temperature, outlet exhaust temperature, outside air temperature of the oxidation catalyst, and hydrocarbon supply amount supplied from the supply means
  • the first heat generation rate calculating means for calculating the hydrocarbon heat generation rate in the oxidation catalyst in consideration of the amount of heat loss to the outside air, the calculated hydrocarbon heat generation rate in the oxidation catalyst, and the A slip amount calculating means for calculating an unburned hydrocarbon slip amount passing through the oxidation catalyst based on a hydrocarbon supply amount; and at least an inlet exhaust temperature, an outlet exhaust temperature, an outside air temperature and A second heat generation rate calculating means for calculating a hydrocarbon heat generation rate in the filter in consideration of a heat loss amount to the outside air
  • the deterioration diagnosis of the catalytic function of the DPF can be performed with high accuracy.
  • FIG. 1 is a schematic overall configuration diagram showing an intake / exhaust system of an engine to which a diagnostic device according to an embodiment of the present invention is applied. It is a schematic diagram explaining the energy preservation
  • a diesel engine (hereinafter simply referred to as an engine) 10 is provided with an intake manifold 10a and an exhaust manifold 10b.
  • An intake passage 11 for introducing fresh air is connected to the intake manifold 10a, and an exhaust passage 12 for releasing exhaust gas to the atmosphere is connected to the exhaust manifold 10b.
  • an air cleaner 30, a MAF sensor 31, a supercharger compressor 32a, and an intercooler 33 are provided in this order from the intake upstream side.
  • a turbocharger turbine 32b, a pre-stage post-treatment device 14, and a post-stage post-treatment device 20 are provided in order from the exhaust upstream side.
  • reference numeral 36 denotes an outside air temperature sensor.
  • the pre-stage post-treatment device 14 is configured by arranging a DOC 15 and a DPF 16 in order from the exhaust upstream side in a cylindrical catalyst case 14a. Further, the exhaust pipe injection device 13 is upstream of the DOC 15, the DOC inlet temperature sensor 17 is upstream of the DOC 15, the DOC outlet temperature sensor 18 is between the DOC 15 and the DPF 16, and the DPF outlet temperature sensor is downstream of the DPF 16. 19 are provided. Further, a differential pressure sensor 37 that detects a differential pressure between the upstream side and the downstream side of the DPF 16 is provided before and after the DPF 16.
  • the exhaust pipe injection device 13 injects unburned fuel (mainly HC) into the exhaust passage 12 in accordance with an instruction signal output from an electronic control unit (hereinafter, ECU) 40.
  • ECU electronice control unit
  • this in-pipe injection device 13 may be omitted.
  • the DOC 15 is formed, for example, by supporting a catalyst component on the surface of a ceramic carrier such as a cordierite honeycomb structure.
  • a ceramic carrier such as a cordierite honeycomb structure.
  • the DPF 16 is formed, for example, by arranging a large number of cells partitioned by porous partition walls along the flow direction of the exhaust gas and alternately plugging the upstream side and the downstream side of these cells.
  • the DPF 16 collects PM in the exhaust gas in the pores and surfaces of the partition walls, and when the amount of accumulated PM reaches a predetermined amount, so-called forced regeneration is performed to remove the PM.
  • the forced regeneration is performed by supplying unburned fuel (HC) to the DOC 15 by the exhaust pipe injection device 13 or post injection, and increasing the exhaust temperature flowing into the DPF 16 to the PM combustion temperature (for example, about 600 ° C.). .
  • the DPF 16 has an ability to oxidize unburned HC slipped without being oxidized by the upstream DOC 15.
  • the DOC inlet temperature sensor 17 detects the upstream exhaust temperature flowing into the DOC 15 (hereinafter referred to as DOC inlet exhaust temperature).
  • the DOC outlet temperature sensor 18 detects the downstream exhaust temperature flowing out of the DOC 15 (hereinafter referred to as DOC outlet exhaust temperature or DPF inlet exhaust temperature).
  • the DPF outlet temperature sensor 19 detects the downstream exhaust temperature flowing out from the DPF 16 (hereinafter referred to as the DPF outlet exhaust temperature). The detected values of these temperature sensors 17 to 19 are output to the electrically connected ECU 40.
  • the post-stage post-treatment device 20 includes a urea water injection device 21 and an SCR 22 arranged in a cylindrical case 20a in order from the exhaust upstream side.
  • An SCR inlet temperature sensor 23 is provided on the upstream side of the SCR 22.
  • the urea water injection device 21 injects urea water in a urea water tank (not shown) into the exhaust passage 12 between the pre-stage post-treatment device 14 and the post-stage post-treatment device 20 in response to an instruction signal output from the ECU 40. To do.
  • the injected urea water is hydrolyzed by exhaust heat to generate NH 3 and is supplied as a reducing agent to the downstream SCR 22.
  • the SCR 22 is formed, for example, by supporting iron zeolite on the surface of a ceramic carrier such as a honeycomb structure.
  • the SCR 22 adsorbs NH 3 supplied as a reducing agent and reduces and purifies NOx from the exhaust gas passing through the adsorbed NH 3 .
  • the ECU 40 controls the engine 10, the exhaust pipe injection device 13, and the like, and includes a known CPU, ROM, RAM, input port, output port, and the like. Further, the ECU 40 includes a DOC heat generation rate calculation unit 41, a DOC deterioration determination unit 42, an HC slip amount calculation unit 43, a DPF heat generation rate calculation unit 44, and a DPF deterioration determination unit 45 as some functional elements. . Each of these functional elements will be described as being included in the ECU 40 which is an integral hardware, but any one of them can be provided in separate hardware.
  • the DOC heat generation rate calculation unit 41 is an example of the first heat generation rate calculation means of the present invention, and calculates the actual heat generation rate C DOC_act% of HC oxidized by the DOC 15 during the forced regeneration of the DPF 16.
  • a detailed calculation procedure of the HC heat generation rate in the DOC 15 will be described.
  • the actual heating value C DOC_act of supplied from the exhaust pipe injector 13 during forced regeneration in DOC15 HC is exhausted between the upstream side of the exhaust energy Q DOC_in and downstream exhaust energy Q DOC_out of DOC15 It is obtained by adding the amount of heat loss Q DOC_lost released from the DOC 15 to the outside air to the energy difference.
  • the upstream exhaust energy Q DOC_in is calculated based on Equation 1 below, and the downstream exhaust energy Q DOC_out is calculated based on Equation 2 below.
  • c exh represents exhaust specific heat.
  • m exh is the exhaust gas flow rate, and is obtained from the detection value of the MAF sensor 31, the fuel injection amount of the engine 10, and the like.
  • the exhaust flow rate m exh may be obtained directly from an exhaust flow sensor (not shown) or the like.
  • T DOC_in is the DOC inlet exhaust temperature, and is acquired by the DOC inlet temperature sensor 17.
  • T DOC_out is the DOC outlet exhaust temperature, and is acquired by the DOC outlet temperature sensor 18.
  • the heat loss amount Q DOC_natural due to natural convection is calculated based on the following Equation 3.
  • a s_DOC indicates an effective area of the outer peripheral surface of the DOC 15 (or the outer peripheral surface of the portion where the DOC 15 of the catalyst case 14a is provided).
  • T DOC_brick is the internal temperature of the DOC 15 and is obtained as an average value of the DOC inlet exhaust temperature T DOC_in and the DOC outlet exhaust temperature T DOC_out .
  • T ambient is the outside air temperature and is acquired by the outside air temperature sensor 36.
  • h n_DOC is the heat transfer coefficient of natural convection and is obtained from the following Equation 4.
  • Equation 4 k represents the thermal conductivity of air.
  • L n_DOC is the representative length of the DOC 15 and is appropriately set according to the capacity of the DOC 15 and the like.
  • Nu n_DOC indicates the Nusselt number of natural convection.
  • the DOC 15 has a columnar shape, and the catalyst case 14a that accommodates the DOC 15 is formed in a substantially cylindrical shape. Therefore, it is considered that the oxidation heat generated in the DOC 15 is dissipated to the outside air through the entire surface of the cylindrical outer peripheral surface of the DOC 15 and the catalyst case 14a. Assuming that the heat radiation by natural convection is transmitted from the entire surface of the outer peripheral surface of the cylinder with the axis oriented in the horizontal direction, the Nusselt number Nu n_DOC can be obtained from the following Equation 5 where the glassphos number is Gr and the Prandtl number is Pr.
  • the heat loss amount Q DOC_forced due to forced convection is calculated based on the following Equation 6.
  • a f_DOC indicates an effective area of the outer peripheral surface of the DOC 15 (or the outer peripheral surface of the portion where the DOC 15 of the catalyst case 14a is provided).
  • h f_DOC is a heat transfer coefficient of forced convection and is obtained from Equation 7 below.
  • L f_DOC is a representative length of the DOC 15 and is appropriately set according to the capacity of the DOC 15 and the like.
  • Nu f_DOC represents the Nusselt number of forced convection.
  • the catalyst case 14a accommodating the DOC 15 is fixed to the lower part of the chassis frame S of the vehicle body, and a transmission TM or the like is disposed in front thereof. Therefore, it can be assumed that the traveling wind flowing from the front of the vehicle body to the lower part during traveling is a turbulent flow on a flat plate that affects only the lower surface of the DOC 15 (or the catalyst case 14a). That is, the forced convection Nusselt number Nu f — DOC is obtained from the following Equation 8 derived by solving a turbulent heat transfer equation on a flat plate.
  • Equation 8 Re represents the Reynolds number.
  • the Reynolds number Re is obtained from Equation 9 below, where the average velocity of air is v, the air density is ⁇ , the representative length of DOC 15 is L f_DOC , and the kinematic viscosity coefficient is ⁇ .
  • the DOC heat generation rate calculation unit 41 calculates the difference in the exhaust energy between the upstream exhaust energy Q DOC_in calculated based on the above-described equation 1 and the downstream exhaust energy Q DOC_out calculated based on the above-described equation 2.
  • the DOC deterioration determination unit 42 is an example of a determination unit according to the present invention, and determines the deterioration state of the DOC 15 based on the HC actual heat generation rate C DOC_ACT% calculated by the HC heat generation rate calculation unit 41. More specifically, the ECU 40 stores an HC heat generation rate threshold value C DOC_STD% obtained when a predetermined amount of HC is almost completely oxidized in the DOC 15 and obtained in advance through experiments or the like.
  • the DOC deterioration determination unit 42 HC purification performance is determined as a deteriorated state. Note that the state in which the HC purification performance of the DOC 15 has deteriorated is different from the normal HC purification rate due to, for example, aging degradation or breakage as shown in FIG. 4 (the catalyst activation temperature is shifted to the high temperature side). State).
  • the DPF heat generation rate calculation unit 44 is an example of the second heat generation rate calculation means of the present invention, and calculates the actual heat generation rate C DPF_act% of HC that slips the DOC 15 and flows into the DPF 16 during forced regeneration.
  • C DPF_act% of HC that slips the DOC 15 and flows into the DPF 16 during forced regeneration.
  • the actual heating value C DPF_act of HC to be oxidized by the DPF 16 to slip DOC15 is the exhaust energy difference between the exhaust energy Q DPF_out the upstream side of the exhaust energy Q DPF_in and downstream of the DPF 16, It is obtained by adding the amount of heat loss Q DPF_lost released from the DPF 16 to the outside air.
  • the upstream exhaust energy Q DPF_in is calculated based on Equation 10 below, and the downstream exhaust energy Q DPF_out is calculated based on Equation 11 below.
  • T DPF_in is the DPF inlet exhaust temperature, and is acquired by the DOC outlet temperature sensor 18.
  • T DPF_out is the DPF outlet exhaust temperature, and is acquired by the DPF outlet temperature sensor 19.
  • the DPF outlet exhaust temperature TDPF_out may be acquired by the SCR inlet temperature sensor 23.
  • Equation 12 The amount of heat loss Q DPF_natural due to natural convection is calculated based on Equation 12 below.
  • a s_DPF represents the effective area of the outer peripheral surface of the DPF 16 (or the outer peripheral surface of the portion of the catalyst case 14a where the DPF 16 is provided).
  • T DPF_brick is the internal temperature of the DPF 16 and is obtained as an average value of the DPF inlet exhaust temperature T DPF_in and the DPF outlet exhaust temperature T DPF_out .
  • h n_DPF is a natural convection heat transfer coefficient, and is obtained from the following Equation 13.
  • L n_DPF is a representative length of the DPF 16 and is appropriately set according to the capacity of the DPF 16 and the like.
  • Nu n_DPF is the natural convection Nusselt number, and can be obtained from the following equation 14 assuming that heat is radiated from the entire cylindrical outer peripheral surface of the DPF 16 and the catalyst case 14a as in the above equation 5.
  • the heat loss amount Q DPF_forced due to forced convection is calculated based on the following Equation 15.
  • a f_DPF indicates the effective area of the outer peripheral surface of the DPF 16 (or the outer peripheral surface of the portion where the DPF 16 of the catalyst case 14a is provided).
  • h f_DPF is a heat transfer coefficient of forced convection and is obtained from the following equation (16).
  • L f_DPF is a representative length of the DPF 16 and is appropriately set according to the capacity of the DPF 16 and the like.
  • Nu f_DPF is the Nusselt number of forced convection, and assuming that the forced convection is a turbulent flow on a flat plate that affects only the lower surface of the DPF 16 (or the catalyst case 14a), as in Equation 8 above, The following equation 17 can be obtained.
  • Equation 17 The Reynolds number Re in Equation 17 is obtained from Equation 18 below, where the average velocity of air is v, the air density is ⁇ , the representative length of DPF 16 is L f — DPF, and the kinematic viscosity coefficient is ⁇ .
  • the DPF deterioration determination unit 45 is an example of a determination unit of the present invention, and determines the deterioration state of the DPF 16 based on the HC actual heat generation amount CDPF_actT% calculated by the DPF heat generation rate calculation unit 44. More specifically, the ECU 40 stores an HC heat generation rate threshold value CDPF_STD% obtained in advance by experiments or the like when a predetermined amount of HC is almost completely oxidized in the DPF 16.
  • the DPF deterioration determination unit 45 HC purification performance is determined as a deteriorated state.
  • step (hereinafter, simply referred to as S) 100 it is determined whether or not the PM deposition amount PM depo deposited on the DPF 16 has reached the upper limit value PM MAX based on the differential pressure across the DPF 16. .
  • the present control proceeds to S110.
  • the deterioration determination of the DOC 15 is performed by comparing the HC actual heat rate C DOC_act% calculated in S130 with the HC heat rate threshold value C DOC_STD% .
  • the difference ⁇ C DOC_% between the HC heat generation rate threshold C DOC_STD% and the HC actual heat generation rate C DOC_act% has not reached the upper limit threshold ⁇ C MAX (No)
  • the HC oxidation performance of the DOC 15 is normal, so this control is S100. Returned to That is, the determination of the deterioration of the DOC 15 is suspended until the next forced regeneration.
  • the difference ⁇ C DOC_% has reached the upper limit threshold ⁇ C MAX (Yes)
  • the HC oxidation capability (HC purification performance) of the DOC 15 is determined to be a deteriorated state in S150.
  • the present control proceeds to S160, and the slip amount HC slp_qty is calculated.
  • the slip amount HC slp_qty is obtained by multiplying the exhaust pipe injection amount HC inj_qty by the HC actual heat generation rate C DOC_ACT% .
  • the HC actual heat generation amount C DPF_act in the DPF 16 is added to the exhaust energy difference between the upstream exhaust energy Q DPF_in and the downstream exhaust energy Q DPF_out by the heat loss amount Q DPF_lost radiated to the outside air. Is calculated. Furthermore, in S180, the HC actual heat generation rate C DPF_act% in the DPF 16 is calculated by dividing the HC actual heat generation amount C DPF_act calculated in S170 by the theoretical heat generation amount C DPF_theo of HC slipped from the DOC15 . The theoretical heating value C DPF_theo is obtained by multiplying the slip quantity HC slp_qty by the theoretical heating rate C theo% of HC.
  • the deterioration determination of the DPF 16 is performed by comparing the HC actual heat generation rate C DPF_act% calculated in S170 with the HC heat generation rate threshold C DPF_STD% .
  • the difference ⁇ C DPF_% between the HC heat generation rate threshold C DPF_STD% and the HC actual heat generation rate C DPF_act% does not reach the upper limit threshold ⁇ C MAX (No)
  • the HC oxidation performance of the DPF 16 is normal, so this control is performed in S100.
  • the actual calorific value of HC supplied to the DOC 15 during forced regeneration is based on the exhaust energy difference between the upstream side and the downstream side of the DOC 15 and the amount of heat loss radiated from the DOC 15 to the outside air. Calculated. Further, the actual calorific value of HC slipped from the DOC 15 and oxidized by the DPF 16 is calculated based on the exhaust energy difference between the upstream side and the downstream side of the DPF 16 and the heat loss amount radiated from the DPF 16 to the outside air.
  • the diagnostic apparatus of the present embodiment it is configured to calculate the HC heat generation amount of the DOC 15 and the DPF 16 with higher accuracy by considering the amount of heat loss to the outside air than the method of calculating the HC heat generation amount of the DOC 15 and the DPF 16 based only on the upstream and downstream exhaust temperature differences. ing. Therefore, according to the diagnostic apparatus of the present embodiment, it is possible to diagnose the deterioration of the HC oxidation ability of the DOC 15 and the DPF 16 with high accuracy.
  • the amount of heat loss to the outside air is calculated using model equations including natural convection heat transfer coefficients (Equations 3 to 5, 12 to 14) and model expressions including forced convection heat transfer coefficients. Calculation is performed based on (Formulas 6 to 9, 15 to 18).
  • the heat transfer coefficient of natural convection is set from the Nusselt number assumed to radiate heat from the entire cylindrical outer peripheral surface of DOC15 or DPF16, and the heat transfer coefficient of forced convection affects the lower surface of DOC15 or DPF16. It is set from the Nusselt number assumed to be turbulent flow on a given flat plate.
  • the heat loss amount to the outside air is accurately calculated based on a model formula that takes into account the shape of the DOC 15, DPF 16, catalyst case 14 a, etc., arrangement position, and the influence of traveling wind. Therefore, according to the diagnostic device of the present embodiment, it is possible to calculate an accurate HC actual heat generation amount taking into account the influence of the shape, arrangement, forced convection, and the like, and the diagnostic accuracy can be improved reliably.
  • the deterioration diagnosis has been described as being performed at the time of forced regeneration of the DPF 16, but may be performed at times other than forced regeneration.
  • the exhaust pipe injection (or post injection) may be executed regardless of the PM accumulation amount of the DPF 16.
  • the deterioration diagnosis of the DPF 16 has been described as being performed when the HC slips from the DOC 15, it may be configured to be performed even when the DOC 15 is not deteriorated. In this case, it is only necessary to intentionally slip the HC from the DOC 15 by increasing the injection amount of the exhaust pipe injection (or post injection).
  • the engine 10 is not limited to a diesel engine, and can be widely applied to other internal combustion engines such as a gasoline engine.

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Abstract

The present invention relates to a diagnostic device which performs highly accurate diagnosis of the deterioration of a diesel particulate filter (DPF). The present invention is provided with: a diesel oxidation catalyst (DOC) (15) for oxidizing hydrocarbons (HC) included in an exhaust gas; a DPF (16) for capturing particulate matter (PM) included in the exhaust gas; an intra-exhaust-pipe injection device (13) capable of supplying HC to the DOC (15); a DOC heat-generation-rate calculation unit (41) which calculates, on the basis of the temperature of the exhaust gas at an inlet of the DOC (15), the temperature of the exhaust gas at an outlet of the DOC (15), the outside-air temperature, and a HC supply amount, a HC heat-generation rate of the HC in the DOC (15), said HC heat-generation rate being considered as a heat loss amount to the outside air; a HC-slip-amount calculation unit (43) which calculates, on the basis of the HC heat-generation rate and the HC supply amount, a HC slip amount of the HC passing through the DOC (15); a DPF heat-generation-rate calculation unit (44) which calculates, on the basis of the temperature of the exhaust gas at an inlet of the DPF (16), the temperature of the exhaust gas at an outlet of the DPF (16), the outside-air temperature, and the HC slip amount, a HC heat-generation rate of the HC inside the DPF (16), said HC heat-generation rate being considered as a heat loss amount to the outside air; and a DPF-deterioration determination unit (45) which determines the deterioration of the DPF (16), on the basis of the HC heat-generation rate of the HC inside the DPF (16).

Description

診断装置Diagnostic equipment
　本発明は、診断装置に関し、特に、内燃機関の排気系に設けられる排気浄化触媒の劣化診断に関する。 The present invention relates to a diagnostic apparatus, and more particularly, to a deterioration diagnosis of an exhaust purification catalyst provided in an exhaust system of an internal combustion engine.
　ディーゼルエンジン等の排気系に設けられる排気浄化触媒として、排気中に含まれる炭化水素（ＨＣ）、一酸化炭素（ＣＯ）、一酸化窒素（ＮＯ）を酸化する酸化触媒（Diesel Oxidation Catalyst：ＤＯＣ）が知られている。また、排気中に含まれる粒子状物質（Particulate Matter：ＰＭ）を捕集するディーゼル・パティキュレイト・フィルタ（Diesel Particulate Filter：ＤＰＦ）等も知られている。 Oxidation catalyst (Diesel Oxidation Catalyst: DOC) that oxidizes hydrocarbons (HC), carbon monoxide (CO), and nitric oxide (NO) contained in the exhaust as an exhaust purification catalyst installed in exhaust systems such as diesel engines It has been known. A diesel particulate filter (DPF) that collects particulate matter (PM) contained in exhaust gas is also known.
　ＤＯＣのＨＣ酸化能力が劣化すると、ＤＰＦの強制再生時に排気管内噴射等によってＤＯＣに供給されたＨＣの一部は、酸化されずに下流側のＤＰＦにスリップする。ＤＰＦもＨＣ酸化能を有するため、ＤＯＣからスリップしたＨＣはＤＰＦで酸化浄化され得る。しかしながら、ＤＰＦのＨＣ酸化性能も劣化すると、ＤＯＣからスリップした未燃焼のＨＣがＤＰＦを通過して大気に放出され、エミッションの悪化を招く可能性がある。そのため、ＤＯＣやＤＰＦのＨＣ酸化能力を車載状態（On-Board）で診断する要請がある（例えば、特許文献１参照）。 When the HC oxidizing ability of the DOC deteriorates, a part of the HC supplied to the DOC by injection in the exhaust pipe during the forced regeneration of the DPF is slipped to the downstream DPF without being oxidized. Since DPF also has HC oxidizing ability, HC slipped from DOC can be oxidized and purified by DPF. However, if the HC oxidation performance of the DPF also deteriorates, unburned HC slipped from the DOC may pass through the DPF and be released to the atmosphere, leading to a deterioration in emissions. Therefore, there is a request for diagnosing the HC oxidation ability of DOC and DPF in an on-board state (for example, see Patent Document 1).
特開２００３－１０６１４０号公報JP 2003-106140 A
　ＨＣ酸化性能を診断する手法としては、ＤＯＣやＤＰＦの上流側及び下流側に排気温度センサを設け、これら排気温度センサの検出値から推定したＨＣ発熱量に基づいて診断する技術がある。しかしながら、ＤＯＣやＤＰＦは車体下部に配置された排気管（触媒ケース）内に収容されるため、ＨＣの酸化熱は走行風等の影響を受けてその一部が外気に放熱される。すなわち、排気温度センサの検出値のみに基づいた診断手法では、外気への熱損失量を考慮していないため、高精度な診断を行えない可能性がある。 As a method for diagnosing the HC oxidation performance, there is a technique in which exhaust temperature sensors are provided on the upstream side and downstream side of the DOC and DPF, and a diagnosis is made based on the HC heat generation amount estimated from the detected values of these exhaust temperature sensors. However, since DOC and DPF are accommodated in an exhaust pipe (catalyst case) disposed at the lower part of the vehicle body, the oxidization heat of HC is influenced by running wind and a part of it is radiated to the outside air. That is, the diagnosis method based only on the detection value of the exhaust temperature sensor does not take into account the amount of heat loss to the outside air, and therefore there is a possibility that highly accurate diagnosis cannot be performed.
　開示の診断装置は、ＤＰＦの触媒機能の劣化診断を高精度に行うことを目的とする。 The disclosed diagnostic device aims to perform a deterioration diagnosis of the catalytic function of the DPF with high accuracy.
　開示の診断装置は、内燃機関の排気系に設けられて、排気中に含まれる少なくとも炭化水素を酸化する酸化触媒と、前記酸化触媒の排気下流側に設けられて、排気中に含まれる粒子状物質を捕集するフィルタと、前記酸化触媒に炭化水素を供給可能な供給手段と、少なくとも前記酸化触媒の入口排気温度、出口排気温度、外気温度及び、前記供給手段から供給される炭化水素供給量に基づいて、外気への熱損失量を考慮した前記酸化触媒内での炭化水素発熱率を演算する第１発熱率演算手段と、演算された前記酸化触媒内での炭化水素発熱率及び、前記炭化水素供給量に基づいて、前記酸化触媒を通過する未燃焼の炭化水素スリップ量を演算するスリップ量演算手段と、少なくとも前記フィルタの入口排気温度、出口排気温度、外気温度及び、演算された前記炭化水素スリップ量に基づいて、外気への熱損失量を考慮した前記フィルタ内での炭化水素発熱率を演算する第２発熱率演算手段と、演算された前記フィルタ内での炭化水素発熱率に基づいて、前記フィルタの劣化を判定する判定手段とを備える。 The disclosed diagnostic apparatus includes an oxidation catalyst that is provided in an exhaust system of an internal combustion engine and that oxidizes at least hydrocarbons contained in exhaust gas, and is provided on the exhaust gas downstream side of the oxidation catalyst and is included in exhaust gas particles. Filter for collecting substances, supply means capable of supplying hydrocarbons to the oxidation catalyst, inlet exhaust temperature, outlet exhaust temperature, outside air temperature of the oxidation catalyst, and hydrocarbon supply amount supplied from the supply means The first heat generation rate calculating means for calculating the hydrocarbon heat generation rate in the oxidation catalyst in consideration of the amount of heat loss to the outside air, the calculated hydrocarbon heat generation rate in the oxidation catalyst, and the A slip amount calculating means for calculating an unburned hydrocarbon slip amount passing through the oxidation catalyst based on a hydrocarbon supply amount; and at least an inlet exhaust temperature, an outlet exhaust temperature, an outside air temperature and A second heat generation rate calculating means for calculating a hydrocarbon heat generation rate in the filter in consideration of a heat loss amount to the outside air based on the calculated hydrocarbon slip amount, and a calculated in the filter Determination means for determining deterioration of the filter based on a hydrocarbon heat generation rate.
　開示の診断装置によれば、ＤＰＦの触媒機能の劣化診断を高精度に行うことができる。 According to the disclosed diagnostic apparatus, the deterioration diagnosis of the catalytic function of the DPF can be performed with high accuracy.
本発明の一実施形態に係る診断装置が適用されたエンジンの吸排気系を示す模式的な全体構成図である。1 is a schematic overall configuration diagram showing an intake / exhaust system of an engine to which a diagnostic device according to an embodiment of the present invention is applied. ＤＯＣに供給されたＨＣの酸化及び、ＤＯＣからＤＰＦにスリップしたＨＣの酸化によるエネルギ保存を説明する模式的な図である。It is a schematic diagram explaining the energy preservation | save by oxidation of HC supplied to DOC, and oxidation of HC slipped from DOC to DPF. 強制対流の影響によるＤＯＣ及び、ＤＰＦの熱損失を説明する模式的な側面図である。It is a typical side view explaining the heat loss of DOC and DPF by the influence of forced convection. 正常なＤＯＣと劣化したＤＯＣのＨＣ酸化能力（ＨＣ浄化性能）を比較した図である。It is the figure which compared HC oxidation ability (HC purification | cleaning performance) of normal DOC and degraded DOC. 本実施形態の診断装置による制御内容を示すフローチャートである。It is a flowchart which shows the control content by the diagnostic apparatus of this embodiment.
　以下、添付図面に基づいて、本発明の一実施形態に係る診断装置を説明する。同一の部品には同一の符号を付してあり、それらの名称及び機能も同じである。したがって、それらについての詳細な説明は繰返さない。 Hereinafter, a diagnostic apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
　図１に示すように、ディーゼルエンジン（以下、単にエンジンという）１０には、吸気マニホールド１０ａと排気マニホールド１０ｂとが設けられている。吸気マニホールド１０ａには新気を導入する吸気通路１１が接続され、排気マニホールド１０ｂには排気を大気に放出する排気通路１２が接続されている。 As shown in FIG. 1, a diesel engine (hereinafter simply referred to as an engine) 10 is provided with an intake manifold 10a and an exhaust manifold 10b. An intake passage 11 for introducing fresh air is connected to the intake manifold 10a, and an exhaust passage 12 for releasing exhaust gas to the atmosphere is connected to the exhaust manifold 10b.
　吸気通路１１には、吸気上流側から順に、エアクリーナ３０、ＭＡＦセンサ３１、過給機のコンプレッサ３２ａ、インタークーラ３３が設けられている。排気通路１２には、排気上流側から順に、過給機のタービン３２ｂ、前段後処理装置１４、後段後処理装置２０が設けられている。なお、図１中において、符号３６は外気温度センサを示している。 In the intake passage 11, an air cleaner 30, a MAF sensor 31, a supercharger compressor 32a, and an intercooler 33 are provided in this order from the intake upstream side. In the exhaust passage 12, a turbocharger turbine 32b, a pre-stage post-treatment device 14, and a post-stage post-treatment device 20 are provided in order from the exhaust upstream side. In FIG. 1, reference numeral 36 denotes an outside air temperature sensor.
　前段後処理装置１４は、円筒状の触媒ケース１４ａ内に排気上流側から順に、ＤＯＣ１５と、ＤＰＦ１６とを配置して構成されている。また、ＤＯＣ１５の上流側には排気管内噴射装置１３、ＤＯＣ１５の上流側にはＤＯＣ入口温度センサ１７、ＤＯＣ１５とＤＰＦ１６との間にはＤＯＣ出口温度センサ１８、ＤＰＦ１６の下流側にはＤＰＦ出口温度センサ１９がそれぞれ設けられている。さらに、ＤＰＦ１６の前後には、ＤＰＦ１６の上流側と下流側との差圧を検出する差圧センサ３７が設けられている。 The pre-stage post-treatment device 14 is configured by arranging a DOC 15 and a DPF 16 in order from the exhaust upstream side in a cylindrical catalyst case 14a. Further, the exhaust pipe injection device 13 is upstream of the DOC 15, the DOC inlet temperature sensor 17 is upstream of the DOC 15, the DOC outlet temperature sensor 18 is between the DOC 15 and the DPF 16, and the DPF outlet temperature sensor is downstream of the DPF 16. 19 are provided. Further, a differential pressure sensor 37 that detects a differential pressure between the upstream side and the downstream side of the DPF 16 is provided before and after the DPF 16.
　排気管内噴射装置１３は、電子制御ユニット（以下、ＥＣＵ）４０から出力される指示信号に応じて、排気通路１２内に未燃燃料（主にＨＣ）を噴射する。なお、エンジン１０の多段噴射によるポスト噴射を用いる場合は、この排気管内噴射装置１３を省略してもよい。 The exhaust pipe injection device 13 injects unburned fuel (mainly HC) into the exhaust passage 12 in accordance with an instruction signal output from an electronic control unit (hereinafter, ECU) 40. In addition, when using the post injection by the multistage injection of the engine 10, this in-pipe injection device 13 may be omitted.
　ＤＯＣ１５は、例えば、コーディエライトハニカム構造体等のセラミック製担体表面に触媒成分を担持して形成されている。ＤＯＣ１５は、排気管内噴射装置１３又はポスト噴射によってＨＣが供給されると、これを酸化して排気温度を上昇させる。また、ＤＯＣ１５は、排気ガス中のＮＯを酸化してＮＯ2を生成することで、排気中のＮＯに対するＮＯ2の比率を増加させる。 The DOC 15 is formed, for example, by supporting a catalyst component on the surface of a ceramic carrier such as a cordierite honeycomb structure. When HC is supplied by the in-pipe injection device 13 or post injection, the DOC 15 oxidizes this and raises the exhaust temperature. Further, the DOC 15 generates NO 2 by oxidizing NO in the exhaust gas, thereby increasing the ratio of NO 2 to NO in the exhaust gas.
　ＤＰＦ１６は、例えば、多孔質性の隔壁で区画された多数のセルを排気の流れ方向に沿って配置し、これらセルの上流側と下流側とを交互に目封止して形成されている。ＤＰＦ１６は、排気中のＰＭを隔壁の細孔や表面に捕集すると共に、ＰＭ堆積量が所定量に達すると、これを燃焼除去するいわゆる強制再生が実行される。強制再生は、排気管内噴射装置１３又はポスト噴射によりＤＯＣ１５に未燃燃料（ＨＣ）を供給し、ＤＰＦ１６に流入する排気温度をＰＭ燃焼温度（例えば、約６００℃）まで昇温することで行われる。また、ＤＰＦ１６は、上流側のＤＯＣ１５で酸化されずにスリップした未燃焼のＨＣを酸化する能力を有している。 The DPF 16 is formed, for example, by arranging a large number of cells partitioned by porous partition walls along the flow direction of the exhaust gas and alternately plugging the upstream side and the downstream side of these cells. The DPF 16 collects PM in the exhaust gas in the pores and surfaces of the partition walls, and when the amount of accumulated PM reaches a predetermined amount, so-called forced regeneration is performed to remove the PM. The forced regeneration is performed by supplying unburned fuel (HC) to the DOC 15 by the exhaust pipe injection device 13 or post injection, and increasing the exhaust temperature flowing into the DPF 16 to the PM combustion temperature (for example, about 600 ° C.). . Further, the DPF 16 has an ability to oxidize unburned HC slipped without being oxidized by the upstream DOC 15.
　ＤＯＣ入口温度センサ１７は、ＤＯＣ１５に流入する上流側の排気温度（以下、ＤＯＣ入口排気温度という）を検出する。ＤＯＣ出口温度センサ１８は、ＤＯＣ１５から流出する下流側の排気温度（以下、ＤＯＣ出口排気温度又は、ＤＰＦ入口排気温度という）を検出する。ＤＰＦ出口温度センサ１９は、ＤＰＦ１６から流出する下流側の排気温度（以下、ＤＰＦ出口排気温度という）を検出する。これら温度センサ１７～１９の検出値は、電気的に接続されたＥＣＵ４０に出力される。 The DOC inlet temperature sensor 17 detects the upstream exhaust temperature flowing into the DOC 15 (hereinafter referred to as DOC inlet exhaust temperature). The DOC outlet temperature sensor 18 detects the downstream exhaust temperature flowing out of the DOC 15 (hereinafter referred to as DOC outlet exhaust temperature or DPF inlet exhaust temperature). The DPF outlet temperature sensor 19 detects the downstream exhaust temperature flowing out from the DPF 16 (hereinafter referred to as the DPF outlet exhaust temperature). The detected values of these temperature sensors 17 to 19 are output to the electrically connected ECU 40.
　後段後処理装置２０は、排気上流側から順に、尿素水噴射装置２１と、円筒状のケース２０ａ内に配置されたＳＣＲ２２とを備えて構成されている。また、ＳＣＲ２２の上流側には、ＳＣＲ入口温度センサ２３が設けられている。 The post-stage post-treatment device 20 includes a urea water injection device 21 and an SCR 22 arranged in a cylindrical case 20a in order from the exhaust upstream side. An SCR inlet temperature sensor 23 is provided on the upstream side of the SCR 22.
　尿素水噴射装置２１は、ＥＣＵ４０から出力される指示信号に応じて、前段後処理装置１４と後段後処理装置２０との間の排気通路１２内に、図示しない尿素水タンク内の尿素水を噴射する。噴射された尿素水は排気熱により加水分解されてＮＨ3に生成され、下流側のＳＣＲ２２に還元剤として供給される。 The urea water injection device 21 injects urea water in a urea water tank (not shown) into the exhaust passage 12 between the pre-stage post-treatment device 14 and the post-stage post-treatment device 20 in response to an instruction signal output from the ECU 40. To do. The injected urea water is hydrolyzed by exhaust heat to generate NH 3 and is supplied as a reducing agent to the downstream SCR 22.
　ＳＣＲ２２は、例えば、ハニカム構造体等のセラミック製担体表面に鉄ゼオライトを担持して形成されている。ＳＣＲ２２は、還元剤として供給されるＮＨ3を吸着すると共に、吸着したＮＨ3で通過する排気ガス中からＮＯｘを還元浄化する。 The SCR 22 is formed, for example, by supporting iron zeolite on the surface of a ceramic carrier such as a honeycomb structure. The SCR 22 adsorbs NH 3 supplied as a reducing agent and reduces and purifies NOx from the exhaust gas passing through the adsorbed NH 3 .
　ＥＣＵ４０は、エンジン１０や排気管内噴射装置１３等の各種制御を行うもので、公知のＣＰＵやＲＯＭ、ＲＡＭ、入力ポート、出力ポート等を備えて構成されている。また、ＥＣＵ４０は、ＤＯＣ発熱率演算部４１と、ＤＯＣ劣化判定部４２と、ＨＣスリップ量演算部４３と、ＤＰＦ発熱率演算部４４と、ＤＰＦ劣化判定部４５とを一部の機能要素として有する。これら各機能要素は、一体のハードウェアであるＥＣＵ４０に含まれるものとして説明するが、これらのいずれか一部を別体のハードウェアに設けることもできる。 The ECU 40 controls the engine 10, the exhaust pipe injection device 13, and the like, and includes a known CPU, ROM, RAM, input port, output port, and the like. Further, the ECU 40 includes a DOC heat generation rate calculation unit 41, a DOC deterioration determination unit 42, an HC slip amount calculation unit 43, a DPF heat generation rate calculation unit 44, and a DPF deterioration determination unit 45 as some functional elements. . Each of these functional elements will be described as being included in the ECU 40 which is an integral hardware, but any one of them can be provided in separate hardware.
　ＤＯＣ発熱率演算部４１は、本発明の第１発熱率演算手段の一例であって、ＤＰＦ１６の強制再生時にＤＯＣ１５で酸化されるＨＣの実発熱率ＣDOC_act%を演算する。以下、ＤＯＣ１５内のＨＣ発熱率の詳細な演算手順を説明する。 The DOC heat generation rate calculation unit 41 is an example of the first heat generation rate calculation means of the present invention, and calculates the actual heat generation rate C DOC_act% of HC oxidized by the DOC 15 during the forced regeneration of the DPF 16. Hereinafter, a detailed calculation procedure of the HC heat generation rate in the DOC 15 will be described.
　図２に示すように、強制再生時に排気管内噴射装置１３からＤＯＣ１５に供給されたＨＣの実発熱量ＣDOC_actは、ＤＯＣ１５の上流側の排気エネルギＱDOC_inと下流側の排気エネルギＱDOC_outとの排気エネルギ差に、ＤＯＣ１５から外気に放出される熱損失量ＱDOC_lostを加算することで得られる。 As shown in FIG. 2, the actual heating value C DOC_act of supplied from the exhaust pipe injector 13 during forced regeneration in DOC15 HC is exhausted between the upstream side of the exhaust energy Q DOC_in and downstream exhaust energy Q DOC_out of DOC15 It is obtained by adding the amount of heat loss Q DOC_lost released from the DOC 15 to the outside air to the energy difference.
　上流側の排気エネルギＱDOC_inは、以下の数式１に基づいて演算され、下流側の排気エネルギＱDOC_outは以下の数式２に基づいて演算される。 The upstream exhaust energy Q DOC_in is calculated based on Equation 1 below, and the downstream exhaust energy Q DOC_out is calculated based on Equation 2 below.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　数式１，２において、ｃexhは排気比熱を示している。また、ｍexhは排気流量であって、ＭＡＦセンサ３１の検出値及びエンジン１０の燃料噴射量等から取得される。なお、排気流量ｍexhは、排気流量センサ（不図示）等から直接的に取得してもよい。ＴDOC_inはＤＯＣ入口排気温度であって、ＤＯＣ入口温度センサ１７で取得される。ＴDOC_outはＤＯＣ出口排気温度であって、ＤＯＣ出口温度センサ１８で取得される。 In Expressions 1 and 2, c exh represents exhaust specific heat. Further, m exh is the exhaust gas flow rate, and is obtained from the detection value of the MAF sensor 31, the fuel injection amount of the engine 10, and the like. The exhaust flow rate m exh may be obtained directly from an exhaust flow sensor (not shown) or the like. T DOC_in is the DOC inlet exhaust temperature, and is acquired by the DOC inlet temperature sensor 17. T DOC_out is the DOC outlet exhaust temperature, and is acquired by the DOC outlet temperature sensor 18.
　熱損失量ＱDOC_lostは、自然対流による熱損失量ＱDOC_naturalと、強制対流による熱損失量ＱDOC_forcedとの総和（ＱDOC_lost＝ＱDOC_natural＋ＱDOC_forced）と仮定することができる。 Heat loss quantity Q DOC_lost can assume the heat loss quantity Q DOC_natural by natural convection, the sum of the heat loss quantity Q DOC_forced by forced convection and (Q DOC_lost = Q DOC_natural + Q DOC_forced).
　自然対流による熱損失量ＱDOC_naturalは、以下の数式３に基づいて演算される。 The heat loss amount Q DOC_natural due to natural convection is calculated based on the following Equation 3.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　数式３において、Ａs_DOCはＤＯＣ１５の外周面（又は、触媒ケース１４ａのＤＯＣ１５が設けられた部分の外周面）の有効面積を示している。ＴDOC_brickはＤＯＣ１５の内部温度であって、ＤＯＣ入口排気温度ＴDOC_inとＤＯＣ出口排気温度ＴDOC_outとの平均値として取得される。Ｔambientは外気温度であって、外気温度センサ３６で取得される。ｈn_DOCは自然対流の熱伝達率であって、以下の数式４から得られる。 In Equation 3, A s_DOC indicates an effective area of the outer peripheral surface of the DOC 15 (or the outer peripheral surface of the portion where the DOC 15 of the catalyst case 14a is provided). T DOC_brick is the internal temperature of the DOC 15 and is obtained as an average value of the DOC inlet exhaust temperature T DOC_in and the DOC outlet exhaust temperature T DOC_out . T ambient is the outside air temperature and is acquired by the outside air temperature sensor 36. h n_DOC is the heat transfer coefficient of natural convection and is obtained from the following Equation 4.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　数式４において、ｋは空気の熱伝導率を示している。Ｌn_DOCはＤＯＣ１５の代表長さであって、ＤＯＣ１５の容量等に応じて適宜設定される。Ｎｕn_DOCは、自然対流のヌセルト数を示している。 In Equation 4, k represents the thermal conductivity of air. L n_DOC is the representative length of the DOC 15 and is appropriately set according to the capacity of the DOC 15 and the like. Nu n_DOC indicates the Nusselt number of natural convection.
　一般的に、ＤＯＣ１５は円柱状であって、さらにＤＯＣ１５を収容する触媒ケース１４ａは略円筒状に形成されている。そのため、ＤＯＣ１５内で発生した酸化熱は、これらＤＯＣ１５や触媒ケース１４ａの円筒外周面の全面を介して外気に放熱されると考えられる。自然対流による放熱が、軸心を水平方向に向けた円筒外周面の全面から伝わると仮定すると、ヌセルト数Ｎｕn_DOCは、グラスホス数：Ｇｒ、プラントル数：Ｐｒとする以下の数式５から得られる。 Generally, the DOC 15 has a columnar shape, and the catalyst case 14a that accommodates the DOC 15 is formed in a substantially cylindrical shape. Therefore, it is considered that the oxidation heat generated in the DOC 15 is dissipated to the outside air through the entire surface of the cylindrical outer peripheral surface of the DOC 15 and the catalyst case 14a. Assuming that the heat radiation by natural convection is transmitted from the entire surface of the outer peripheral surface of the cylinder with the axis oriented in the horizontal direction, the Nusselt number Nu n_DOC can be obtained from the following Equation 5 where the glassphos number is Gr and the Prandtl number is Pr.
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　強制対流による熱損失量ＱDOC_forcedは、以下の数式６に基づいて演算される。 The heat loss amount Q DOC_forced due to forced convection is calculated based on the following Equation 6.
Figure JPOXMLDOC01-appb-M000006
Figure JPOXMLDOC01-appb-M000006
　数式６において、Ａf_DOCはＤＯＣ１５の外周面（又は、触媒ケース１４ａのＤＯＣ１５が設けられた部分の外周面）の有効面積を示している。ｈf_DOCは強制対流の熱伝達率であって、以下の数式７から得られる。 In Formula 6, A f_DOC indicates an effective area of the outer peripheral surface of the DOC 15 (or the outer peripheral surface of the portion where the DOC 15 of the catalyst case 14a is provided). h f_DOC is a heat transfer coefficient of forced convection and is obtained from Equation 7 below.
Figure JPOXMLDOC01-appb-M000007
Figure JPOXMLDOC01-appb-M000007
　数式７において、Ｌf_DOCはＤＯＣ１５の代表長さであって、ＤＯＣ１５の容量等に応じて適宜設定される。Ｎｕf_DOCは、強制対流のヌセルト数を示している。 In Expression 7, L f_DOC is a representative length of the DOC 15 and is appropriately set according to the capacity of the DOC 15 and the like. Nu f_DOC represents the Nusselt number of forced convection.
　図３に示すように、一般的にＤＯＣ１５を収容した触媒ケース１４ａは車体のシャシフレームＳの下部に固定され、その前方には変速機ＴＭ等が配置されている。そのため、走行時に車体前方から下部に流れ込む走行風は、ＤＯＣ１５（又は、触媒ケース１４ａ）の下面部にのみ影響を与える平板上の乱流と仮定することができる。すなわち、強制対流のヌセルト数Ｎｕf_DOCは、平板上の乱流熱伝達式を解いて導かれる以下の数式８から得られる。 As shown in FIG. 3, generally, the catalyst case 14a accommodating the DOC 15 is fixed to the lower part of the chassis frame S of the vehicle body, and a transmission TM or the like is disposed in front thereof. Therefore, it can be assumed that the traveling wind flowing from the front of the vehicle body to the lower part during traveling is a turbulent flow on a flat plate that affects only the lower surface of the DOC 15 (or the catalyst case 14a). That is, the forced convection Nusselt number Nu f — DOC is obtained from the following Equation 8 derived by solving a turbulent heat transfer equation on a flat plate.
Figure JPOXMLDOC01-appb-M000008
Figure JPOXMLDOC01-appb-M000008
　数式８において、Ｒｅはレイノルズ数を示している。レイノルズ数Ｒｅは、空気の平均速度：ｖ、空気密度：ρ、ＤＯＣ１５の代表長さ：Ｌf_DOC、動粘性係数：μとする以下の数式９から得られる。 In Equation 8, Re represents the Reynolds number. The Reynolds number Re is obtained from Equation 9 below, where the average velocity of air is v, the air density is ρ, the representative length of DOC 15 is L f_DOC , and the kinematic viscosity coefficient is μ.
Figure JPOXMLDOC01-appb-M000009
Figure JPOXMLDOC01-appb-M000009
　ＤＯＣ発熱率演算部４１は、上述の数式１に基づいて演算した上流側の排気エネルギＱDOC_inと、上述の数式２に基づいて演算した下流側の排気エネルギＱDOC_outとの排気エネルギ差に、上述の数式３～９に基づいて演算した熱損失量ＱDOC_lostを加算することで、強制再生時におけるＤＯＣ１５内のＨＣ実発熱量ＣDOC_actを演算する。そして、ＨＣ実発熱量ＣDOC_actを排気管内噴射（又はポスト噴射）の理論発熱量ＣDOC_theoで除算することで、ＤＯＣ１５内でのＨＣ実発熱率ＣDOC_act%を演算するように構成されている（ＣDOC_act%＝ＣDOC_act／ＣDOC_theo）。理論発熱量ＣDOC_theoは、排気管内噴射量（又はポスト噴射量）ＨＣinj_qtyにＨＣの理論発熱率Ｃtheo%を乗算することで得られる（ＣDOC_theo＝ＨＣinj_qty・Ｃtheo%）。 The DOC heat generation rate calculation unit 41 calculates the difference in the exhaust energy between the upstream exhaust energy Q DOC_in calculated based on the above-described equation 1 and the downstream exhaust energy Q DOC_out calculated based on the above-described equation 2. The HC actual heat generation amount C DOC_act in the DOC 15 at the time of forced regeneration is calculated by adding the heat loss amount Q DOC_lost calculated based on Equations 3 to 9. Then, by dividing the HC actual heating value C DOC_act theoretical calorific C DOC_theo exhaust pipe injection (or post injection), and is configured to calculate the HC actual heat rate C DOC_act% of within DOC15 ( CDOC_act% = CDOC_act / CDOC_theo ). The theoretical heat generation amount C DOC_theo is obtained by multiplying the exhaust pipe injection amount (or post injection amount) HC inj_qty by the HC theoretical heat generation rate C theo% (C DOC_theo = HC inj_qty · C theo% ).
　ＤＯＣ劣化判定部４２は、本発明の判定手段の一例であって、ＨＣ発熱率演算部４１で演算されたＨＣ実発熱率ＣDOC_ACT%に基づいて、ＤＯＣ１５の劣化状態を判定する。より詳しくは、ＥＣＵ４０には、予め実験等により求めた、ＤＯＣ１５内で所定量のＨＣが略完全に酸化した場合のＨＣ発熱率閾値ＣDOC_STD%が記憶されている。ＤＯＣ劣化判定部４２は、ＨＣ発熱率閾値ＣDOC_STD%とＨＣ実発熱率ＣDOC_ACT%との差ΔＣDOC_%がＤＯＣ１５の劣化を示す所定の上限閾値ΔＣMAXに達すると、ＤＯＣ１５のＨＣ酸化能力（ＨＣ浄化性能）を劣化状態と判定する。なお、ＤＯＣ１５のＨＣ浄化性能が劣化した状態とは、図４に示すように、例えば、経年劣化や破損等により正常時のＨＣ浄化率に対して差が生じる（触媒活性温度が高温側にシフトする）状態をいう。 The DOC deterioration determination unit 42 is an example of a determination unit according to the present invention, and determines the deterioration state of the DOC 15 based on the HC actual heat generation rate C DOC_ACT% calculated by the HC heat generation rate calculation unit 41. More specifically, the ECU 40 stores an HC heat generation rate threshold value C DOC_STD% obtained when a predetermined amount of HC is almost completely oxidized in the DOC 15 and obtained in advance through experiments or the like. When the difference ΔC DOC_% between the HC heat generation rate threshold C DOC_STD% and the HC actual heat generation rate C DOC_ACT% reaches a predetermined upper limit threshold ΔC MAX indicating the deterioration of the DOC 15 , the DOC deterioration determination unit 42 HC purification performance) is determined as a deteriorated state. Note that the state in which the HC purification performance of the DOC 15 has deteriorated is different from the normal HC purification rate due to, for example, aging degradation or breakage as shown in FIG. 4 (the catalyst activation temperature is shifted to the high temperature side). State).
　ＨＣスリップ量演算部４３は、本発明のスリップ量演算手段の一例であって、ＨＣ発熱率演算部４１で演算されたＨＣ実発熱率ＣDOC_ACT%及び、排気管内噴射量（又はポスト噴射量）ＨＣinj_qtyに基づいて、ＤＯＣ１５で酸化されずに下流側のＤＰＦ１６に流れ込む未燃焼ＨＣのスリップ量ＨＣslp_qtyを演算する。スリップ量ＨＣslp_qtyは、排気管内噴射量ＨＣinj_qtyにＨＣ実発熱率ＣDOC_ACT%を乗算することで得られる（ＨＣslp_qty＝ＨＣinj_qty×（１－ＣDOC_ACT%））。 The HC slip amount calculation unit 43 is an example of the slip amount calculation means of the present invention, and the HC actual heat generation rate C DOC_ACT% calculated by the HC heat generation rate calculation unit 41 and the exhaust pipe injection amount (or post injection amount). Based on HC inj_qty , the slip amount HC slp_qty of unburned HC flowing into the downstream DPF 16 without being oxidized by the DOC 15 is calculated. The slip amount HC slp_qty is obtained by multiplying the exhaust pipe injection amount HC inj_qty by the HC actual heat generation rate C DOC_ACT% (HC slp_qty = HC inj_qty × (1−C DOC_ACT% )).
　ＤＰＦ発熱率演算部４４は、本発明の第２発熱率演算手段の一例であって、強制再生時にＤＯＣ１５をスリップしてＤＰＦ１６に流れ込んだＨＣの実発熱率ＣDPF_act%を演算する。以下、ＤＰＦ１６内のＨＣ発熱率の詳細な演算手順を説明する。 The DPF heat generation rate calculation unit 44 is an example of the second heat generation rate calculation means of the present invention, and calculates the actual heat generation rate C DPF_act% of HC that slips the DOC 15 and flows into the DPF 16 during forced regeneration. Hereinafter, a detailed calculation procedure of the HC heat generation rate in the DPF 16 will be described.
　図２に示すように、ＤＯＣ１５をスリップしてＤＰＦ１６で酸化されるＨＣの実発熱量ＣDPF_actは、ＤＰＦ１６の上流側の排気エネルギＱDPF_inと下流側の排気エネルギＱDPF_outとの排気エネルギ差に、ＤＰＦ１６から外気に放出される熱損失量ＱDPF_lostを加算することで得られる。 As shown in FIG. 2, the actual heating value C DPF_act of HC to be oxidized by the DPF 16 to slip DOC15 is the exhaust energy difference between the exhaust energy Q DPF_out the upstream side of the exhaust energy Q DPF_in and downstream of the DPF 16, It is obtained by adding the amount of heat loss Q DPF_lost released from the DPF 16 to the outside air.
　上流側の排気エネルギＱDPF_inは、以下の数式１０に基づいて演算され、下流側の排気エネルギＱDPF_outは以下の数式１１に基づいて演算される。 The upstream exhaust energy Q DPF_in is calculated based on Equation 10 below, and the downstream exhaust energy Q DPF_out is calculated based on Equation 11 below.
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000011
　数式１０，１１において、ＴDPF_inはＤＰＦ入口排気温度であって、ＤＯＣ出口温度センサ１８で取得される。ＴDPF_outはＤＰＦ出口排気温度であって、ＤＰＦ出口温度センサ１９で取得される。なお、ＤＰＦ出口排気温度ＴDPF_outは、ＳＣＲ入口温度センサ２３で取得されてもよい。 In Expressions 10 and 11, T DPF_in is the DPF inlet exhaust temperature, and is acquired by the DOC outlet temperature sensor 18. T DPF_out is the DPF outlet exhaust temperature, and is acquired by the DPF outlet temperature sensor 19. The DPF outlet exhaust temperature TDPF_out may be acquired by the SCR inlet temperature sensor 23.
　熱損失量ＱDPF_lostは、自然対流による熱損失量ＱDPF_naturalと、強制対流による熱損失量ＱDPF_forcedとの総和（ＱDPF_lost＝ＱDPF_natural＋ＱDPF_forced）と仮定することができる。 Heat loss quantity Q DPF_lost can assume the heat loss quantity Q DPF_natural by natural convection, the sum of the heat loss quantity Q DPF_forced by forced convection and (Q DPF_lost = Q DPF_natural + Q DPF_forced).
　自然対流による熱損失量ＱDPF_naturalは、以下の数式１２に基づいて演算される。 The amount of heat loss Q DPF_natural due to natural convection is calculated based on Equation 12 below.
Figure JPOXMLDOC01-appb-M000012
Figure JPOXMLDOC01-appb-M000012
　数式１２において、Ａs_DPFはＤＰＦ１６の外周面（又は、触媒ケース１４ａのＤＰＦ１６が設けられた部分の外周面）の有効面積を示している。ＴDPF_brickはＤＰＦ１６の内部温度であって、ＤＰＦ入口排気温度ＴDPF_inとＤＰＦ出口排気温度ＴDPF_outとの平均値として取得される。ｈn_DPFは自然対流の熱伝達率であって、以下の数式１３から得られる。 In Equation 12, A s_DPF represents the effective area of the outer peripheral surface of the DPF 16 (or the outer peripheral surface of the portion of the catalyst case 14a where the DPF 16 is provided). T DPF_brick is the internal temperature of the DPF 16 and is obtained as an average value of the DPF inlet exhaust temperature T DPF_in and the DPF outlet exhaust temperature T DPF_out . h n_DPF is a natural convection heat transfer coefficient, and is obtained from the following Equation 13.
Figure JPOXMLDOC01-appb-M000013
Figure JPOXMLDOC01-appb-M000013
　数式１３において、Ｌn_DPFはＤＰＦ１６の代表長さであって、ＤＰＦ１６の容量等に応じて適宜設定される。Ｎｕn_DPFは、自然対流のヌセルト数であって、上述の数式５と同様に、ＤＰＦ１６や触媒ケース１４ａの円筒外周面の全面から放熱されると仮定すると、以下の数式１４から得ることができる。 In Expression 13, L n_DPF is a representative length of the DPF 16 and is appropriately set according to the capacity of the DPF 16 and the like. Nu n_DPF is the natural convection Nusselt number, and can be obtained from the following equation 14 assuming that heat is radiated from the entire cylindrical outer peripheral surface of the DPF 16 and the catalyst case 14a as in the above equation 5.
Figure JPOXMLDOC01-appb-M000014
Figure JPOXMLDOC01-appb-M000014
　強制対流による熱損失量ＱDPF_forcedは、以下の数式１５に基づいて演算される。 The heat loss amount Q DPF_forced due to forced convection is calculated based on the following Equation 15.
Figure JPOXMLDOC01-appb-M000015
Figure JPOXMLDOC01-appb-M000015
　数式１５において、Ａf_DPFはＤＰＦ１６の外周面（又は、触媒ケース１４ａのＤＰＦ１６が設けられた部分の外周面）の有効面積を示している。ｈf_DPFは強制対流の熱伝達率であって、以下の数式１６から得られる。 In Formula 15, A f_DPF indicates the effective area of the outer peripheral surface of the DPF 16 (or the outer peripheral surface of the portion where the DPF 16 of the catalyst case 14a is provided). h f_DPF is a heat transfer coefficient of forced convection and is obtained from the following equation (16).
Figure JPOXMLDOC01-appb-M000016
Figure JPOXMLDOC01-appb-M000016
　数式１６において、Ｌf_DPFはＤＰＦ１６の代表長さであって、ＤＰＦ１６の容量等に応じて適宜設定される。Ｎｕf_DPFは、強制対流のヌセルト数であって、上述の数式８と同様に、強制対流がＤＰＦ１６（又は、触媒ケース１４ａ）の下面部にのみ影響を与える平板上の乱流と仮定すると、以下の数式１７から得ることができる。 In Expression 16, L f_DPF is a representative length of the DPF 16 and is appropriately set according to the capacity of the DPF 16 and the like. Nu f_DPF is the Nusselt number of forced convection, and assuming that the forced convection is a turbulent flow on a flat plate that affects only the lower surface of the DPF 16 (or the catalyst case 14a), as in Equation 8 above, The following equation 17 can be obtained.
Figure JPOXMLDOC01-appb-M000017
Figure JPOXMLDOC01-appb-M000017
　数式１７のレイノルズ数Ｒｅは、空気の平均速度：ｖ、空気密度：ρ、ＤＰＦ１６の代表長さ：Ｌf_DPF、動粘性係数：μとする以下の数式１８から得られる。 The Reynolds number Re in Equation 17 is obtained from Equation 18 below, where the average velocity of air is v, the air density is ρ, the representative length of DPF 16 is L f — DPF, and the kinematic viscosity coefficient is μ.
Figure JPOXMLDOC01-appb-M000018
Figure JPOXMLDOC01-appb-M000018
　ＤＰＦ発熱率演算部４４は、上述の数式１０に基づいて演算した上流側の排気エネルギＱDPF_inと、上述の数式１１に基づいて演算した下流側の排気エネルギＱDPF_outとの排気エネルギ差に、上述の数式１２～１８に基づいて演算した熱損失量ＱDPF_lostを加算することで、ＤＰＦ１６内のＨＣ実発熱量ＣDPF_actを演算する。そして、ＨＣ実発熱量ＣDPF_actをＤＯＣ１５からスリップしたＨＣの理論発熱量ＣDPF_theoで除算することで、ＤＰＦ１６内でのＨＣ実発熱率ＣDPF_act%を演算するように構成されている（ＣDPF_act%＝ＣDPF_act／ＣDPF_theo）。理論発熱量ＣDPF_theoは、スリップ量ＨＣslp_qtyにＨＣの理論発熱率Ｃtheo%を乗算することで得られる（ＣDPF_theo＝Ｃslp_qty×Ｃtheo%）。 DPF heating rate calculating section 44, the upstream side of the exhaust energy Q DPF_in calculated based on Equation 10 above, the exhaust energy difference between the downstream side of the exhaust energy Q DPF_out calculated based on Equation 11 above, above The HC actual heat generation amount C DPF_act in the DPF 16 is calculated by adding the heat loss amount Q DPF_lost calculated based on the mathematical expressions 12 to 18. Then, by dividing the theoretical calorific value C DPF_theo of HC that slip HC actual heating value C DPF_act from DOC15, and is configured to calculate the HC actual heat rate C DPF_act% of within DPF16 (C DPF_act% = C DPF_act / C DPF_theo ). The theoretical heat generation amount C DPF_theo is obtained by multiplying the slip amount HC slp_qty by the theoretical heat generation rate C theo% of HC (C DPF_theo = C slp_qty × C theo% ).
　ＤＰＦ劣化判定部４５は、本発明の判定手段の一例であって、ＤＰＦ発熱率演算部４４で演算されたＨＣ実発熱量ＣDPF_actT%に基づいて、ＤＰＦ１６の劣化状態を判定する。より詳しくは、ＥＣＵ４０には、予め実験等により求めた、ＤＰＦ１６内で所定量のＨＣが略完全に酸化した場合のＨＣ発熱率閾値ＣDPF_STD%が記憶されている。ＤＰＦ劣化判定部４５は、ＨＣ発熱率閾値ＣDPF_STD%とＨＣ実発熱率ＣDPF_act%との差ΔＣDPF_%がＤＰＦ１６の劣化を示す所定の上限閾値ΔＣMAXに達すると、ＤＰＦ１６のＨＣ酸化能力（ＨＣ浄化性能）を劣化状態と判定する。 The DPF deterioration determination unit 45 is an example of a determination unit of the present invention, and determines the deterioration state of the DPF 16 based on the HC actual heat generation amount CDPF_actT% calculated by the DPF heat generation rate calculation unit 44. More specifically, the ECU 40 stores an HC heat generation rate threshold value CDPF_STD% obtained in advance by experiments or the like when a predetermined amount of HC is almost completely oxidized in the DPF 16. When the difference ΔC DPF_% between the HC heat generation rate threshold C DPF_STD% and the HC actual heat generation rate C DPF_act% reaches a predetermined upper limit threshold ΔC MAX indicating the deterioration of the DPF 16, the DPF deterioration determination unit 45 HC purification performance) is determined as a deteriorated state.
　次に、図５に基づいて、本実施形態の診断装置による制御フローを説明する。 Next, a control flow by the diagnostic apparatus of the present embodiment will be described based on FIG.
　ステップ（以下、ステップを単にＳと記載する）１００では、例えば、ＤＰＦ１６の前後差圧に基づいて、ＤＰＦ１６に堆積したＰＭ堆積量ＰＭdepoが上限値ＰＭMAXに達したか否かが判定される。ＰＭ堆積量ＰＭdepoが上限値ＰＭMAXに達した場合、本制御はＳ１１０に進む。 In step (hereinafter, simply referred to as S) 100, for example, it is determined whether or not the PM deposition amount PM depo deposited on the DPF 16 has reached the upper limit value PM MAX based on the differential pressure across the DPF 16. . When the PM accumulation amount PM depo reaches the upper limit value PM MAX , the present control proceeds to S110.
　Ｓ１１０では、排気管内噴射装置１３による排気管内噴射（又は、ポスト噴射）が開始されて、ＤＰＦ１６の強制再生が実行される。 In S110, exhaust pipe injection (or post injection) by the exhaust pipe injection device 13 is started, and forced regeneration of the DPF 16 is executed.
　Ｓ１２０では、上流側の排気エネルギＱDOC_inと下流側の排気エネルギＱDOC_outとの排気エネルギ差に、外気に放熱される熱損失量ＱDOC_lostを加算することで、ＤＯＣ１５内のＨＣ実発熱量ＣDOC_actが演算される。さらに、Ｓ１３０では、Ｓ１２０で演算した実発熱量ＣDOC_actを排気管内噴射（又はポスト噴射）の理論発熱量ＣDOC_theoで除算することで、ＤＯＣ１５内でのＨＣ実発熱率ＣDOC_act%が演算される。理論発熱量ＣDOC_theoは、排気管内噴射量（又はポスト噴射量）ＨＣinj_qtyにＨＣの理論発熱率Ｃtheo%を乗算することで得られる。 In S120, the exhaust energy difference between the upstream side of the exhaust energy Q DOC_in and downstream of the exhaust energy Q DOC_out, by adding the heat loss Q DOC_lost is radiated to the outside air, HC actual heating value C DOC_act in DOC15 Is calculated. Further, in S130, by dividing the actual heating value C DOC_act calculated in S120 by the theoretical calorific value C DOC_theo exhaust pipe injection (or post injection), HC actual heat rate C DOC_act% of within DOC15 is calculated . The theoretical heat generation amount C DOC_theo is obtained by multiplying the exhaust pipe injection amount (or post injection amount) HC inj_qty by the HC theoretical heat generation rate C theo% .
　Ｓ１４０では、Ｓ１３０で演算したＨＣ実発熱率ＣDOC_act%とＨＣ発熱率閾値ＣDOC_STD%とを比較するＤＯＣ１５の劣化判定が実行される。ＨＣ発熱率閾値ＣDOC_STD%とＨＣ実発熱率ＣDOC_act%との差ΔＣDOC_%が上限閾値ΔＣMAXに達していない場合（Ｎｏ）は、ＤＯＣ１５のＨＣ酸化性能が正常なため、本制御はＳ１００に戻される。すなわち、次回の強制再生までＤＯＣ１５の劣化判定は保留される。一方、差ΔＣDOC_%が上限閾値ΔＣMAXに達している場合（Ｙｅｓ）は、Ｓ１５０でＤＯＣ１５のＨＣ酸化能力（ＨＣ浄化性能）を劣化状態と判定する。 In S140, the deterioration determination of the DOC 15 is performed by comparing the HC actual heat rate C DOC_act% calculated in S130 with the HC heat rate threshold value C DOC_STD% . When the difference ΔC DOC_% between the HC heat generation rate threshold C DOC_STD% and the HC actual heat generation rate C DOC_act% has not reached the upper limit threshold ΔC MAX (No), the HC oxidation performance of the DOC 15 is normal, so this control is S100. Returned to That is, the determination of the deterioration of the DOC 15 is suspended until the next forced regeneration. On the other hand, when the difference ΔC DOC_% has reached the upper limit threshold ΔC MAX (Yes), the HC oxidation capability (HC purification performance) of the DOC 15 is determined to be a deteriorated state in S150.
　Ｓ１５０でＤＯＣ１５を劣化と判定した場合は、強制再生時にＤＯＣ１５に供給されたＨＣがＤＰＦ１６にスリップしている。そのため、本制御はＳ１６０に進み、スリップ量ＨＣslp_qtyが演算される。スリップ量ＨＣslp_qtyは、排気管内噴射量ＨＣinj_qtyにＨＣ実発熱率ＣDOC_ACT%を乗算することで得られる。 If it is determined that the DOC 15 is deteriorated in S150, the HC supplied to the DOC 15 during the forced regeneration slips to the DPF 16. Therefore, the present control proceeds to S160, and the slip amount HC slp_qty is calculated. The slip amount HC slp_qty is obtained by multiplying the exhaust pipe injection amount HC inj_qty by the HC actual heat generation rate C DOC_ACT% .
　Ｓ１７０では、上流側の排気エネルギＱDPF_inと下流側の排気エネルギＱDPF_outとの排気エネルギ差に、外気に放熱される熱損失量ＱDPF_lostを加算することで、ＤＰＦ１６内のＨＣ実発熱量ＣDPF_actが演算される。さらに、Ｓ１８０では、Ｓ１７０で演算したＨＣ実発熱量ＣDPF_actをＤＯＣ１５からスリップしたＨＣの理論発熱量ＣDPF_theoで除算することで、ＤＰＦ１６内でのＨＣ実発熱率ＣDPF_act%が演算される。理論発熱量ＣDPF_theoは、スリップ量ＨＣslp_qtyにＨＣの理論発熱率Ｃtheo%を乗算することで得られる。 In S170, the HC actual heat generation amount C DPF_act in the DPF 16 is added to the exhaust energy difference between the upstream exhaust energy Q DPF_in and the downstream exhaust energy Q DPF_out by the heat loss amount Q DPF_lost radiated to the outside air. Is calculated. Furthermore, in S180, the HC actual heat generation rate C DPF_act% in the DPF 16 is calculated by dividing the HC actual heat generation amount C DPF_act calculated in S170 by the theoretical heat generation amount C DPF_theo of HC slipped from the DOC15 . The theoretical heating value C DPF_theo is obtained by multiplying the slip quantity HC slp_qty by the theoretical heating rate C theo% of HC.
　Ｓ１９０では、Ｓ１７０で演算したＨＣ実発熱率ＣDPF_act%とＨＣ発熱率閾値ＣDPF_STD%とを比較するＤＰＦ１６の劣化判定が実行される。ＨＣ発熱率閾値ＣDPF_STD%とＨＣ実発熱率ＣDPF_act%との差ΔＣDPF_%が上限閾値ΔＣMAXに達していない場合（Ｎｏ）は、ＤＰＦ１６のＨＣ酸化性能が正常なため、本制御はＳ１００に戻される。一方、差ΔＣDPF_%が上限閾値ΔＣMAXに達している場合（Ｙｅｓ）は、Ｓ２００でＤＰＦ１６のＨＣ酸化能力（ＨＣ浄化性能）を劣化状態と判定して、本制御はその後リターンされる。 In S190, the deterioration determination of the DPF 16 is performed by comparing the HC actual heat generation rate C DPF_act% calculated in S170 with the HC heat generation rate threshold C DPF_STD% . When the difference ΔC DPF_% between the HC heat generation rate threshold C DPF_STD% and the HC actual heat generation rate C DPF_act% does not reach the upper limit threshold ΔC MAX (No), the HC oxidation performance of the DPF 16 is normal, so this control is performed in S100. Returned to On the other hand, when the difference ΔC DPF_% has reached the upper limit threshold ΔC MAX (Yes), it is determined in S200 that the HC oxidation capability (HC purification performance) of the DPF 16 is in a deteriorated state, and this control is thereafter returned.
　次に、本実施形態に係る診断装置による作用効果を説明する。 Next, operational effects of the diagnostic apparatus according to the present embodiment will be described.
　本実施形態の診断装置では、強制再生時にＤＯＣ１５に供給されたＨＣの実発熱量は、ＤＯＣ１５の上流側及び下流側の排気エネルギ差と、ＤＯＣ１５から外気に放熱される熱損失量とに基づいて演算される。さらに、ＤＯＣ１５からスリップしてＤＰＦ１６で酸化されるＨＣの実発熱量は、ＤＰＦ１６の上流側及び下流側の排気エネルギ差と、ＤＰＦ１６から外気に放熱される熱損失量とに基づいて演算される。 In the diagnostic device of the present embodiment, the actual calorific value of HC supplied to the DOC 15 during forced regeneration is based on the exhaust energy difference between the upstream side and the downstream side of the DOC 15 and the amount of heat loss radiated from the DOC 15 to the outside air. Calculated. Further, the actual calorific value of HC slipped from the DOC 15 and oxidized by the DPF 16 is calculated based on the exhaust energy difference between the upstream side and the downstream side of the DPF 16 and the heat loss amount radiated from the DPF 16 to the outside air.
　すなわち、ＤＯＣ１５やＤＰＦ１６のＨＣ発熱量を上流側及び下流側の排気温度差のみに基づいて演算する手法に比べて、外気への熱損失量を考慮することで高精度に演算するように構成されている。したがって、本実施形態の診断装置によれば、ＤＯＣ１５やＤＰＦ１６のＨＣ酸化能力の劣化を高精度に診断することができる。 That is, it is configured to calculate the HC heat generation amount of the DOC 15 and the DPF 16 with higher accuracy by considering the amount of heat loss to the outside air than the method of calculating the HC heat generation amount of the DOC 15 and the DPF 16 based only on the upstream and downstream exhaust temperature differences. ing. Therefore, according to the diagnostic apparatus of the present embodiment, it is possible to diagnose the deterioration of the HC oxidation ability of the DOC 15 and the DPF 16 with high accuracy.
　また、本実施形態の診断装置では、外気への熱損失量は、自然対流の熱伝達率を含むモデル式（数式３～５，１２～１４）と、強制対流の熱伝達率を含むモデル式（数式６～９，１５～１８）とに基づいて演算される。このうち、自然対流の熱伝達率は、ＤＯＣ１５やＤＰＦ１６の円筒外周面の全面から放熱されると仮定したヌセルト数から設定され、強制対流の熱伝達率は、ＤＯＣ１５やＤＰＦ１６の下面部に影響を与える平板上の乱流と仮定したヌセルト数から設定される。 In the diagnostic device of the present embodiment, the amount of heat loss to the outside air is calculated using model equations including natural convection heat transfer coefficients (Equations 3 to 5, 12 to 14) and model expressions including forced convection heat transfer coefficients. Calculation is performed based on (Formulas 6 to 9, 15 to 18). Of these, the heat transfer coefficient of natural convection is set from the Nusselt number assumed to radiate heat from the entire cylindrical outer peripheral surface of DOC15 or DPF16, and the heat transfer coefficient of forced convection affects the lower surface of DOC15 or DPF16. It is set from the Nusselt number assumed to be turbulent flow on a given flat plate.
　すなわち、ＤＯＣ１５やＤＰＦ１６、触媒ケース１４ａ等の形状、配置位置、走行風の影響等を考慮したモデル式に基づいて、外気への熱損失量を正確に演算するように構成されている。したがって、本実施形態の診断装置によれば、形状や配置、強制対流等の影響を考慮した正確なＨＣ実発熱量を演算することが可能となり、診断精度を確実に向上することができる。 That is, the heat loss amount to the outside air is accurately calculated based on a model formula that takes into account the shape of the DOC 15, DPF 16, catalyst case 14 a, etc., arrangement position, and the influence of traveling wind. Therefore, according to the diagnostic device of the present embodiment, it is possible to calculate an accurate HC actual heat generation amount taking into account the influence of the shape, arrangement, forced convection, and the like, and the diagnostic accuracy can be improved reliably.
　なお、本発明は、上述の実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で、適宜変形して実施することが可能である。 It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present invention.
　例えば、劣化診断はＤＰＦ１６の強制再生時に行われるものとして説明したが、強制再生時以外に行ってもよい。この場合は、排気管内噴射（又は、ポスト噴射）をＤＰＦ１６のＰＭ堆積量に関係なく実行すればよい。また、ＤＰＦ１６の劣化診断は、ＤＯＣ１５からＨＣがスリップしている場合に行われるものとして説明したが、ＤＯＣ１５が劣化していない場合にも行うように構成してもよい。この場合は、排気管内噴射（又は、ポスト噴射）の噴射量を増加させて、ＤＯＣ１５からＨＣを意図的にスリップさせればよい。また、エンジン１０はディーゼルエンジンに限定されず、ガソリンエンジン等の他の内燃機関にも広く適用することが可能である。 For example, the deterioration diagnosis has been described as being performed at the time of forced regeneration of the DPF 16, but may be performed at times other than forced regeneration. In this case, the exhaust pipe injection (or post injection) may be executed regardless of the PM accumulation amount of the DPF 16. Moreover, although the deterioration diagnosis of the DPF 16 has been described as being performed when the HC slips from the DOC 15, it may be configured to be performed even when the DOC 15 is not deteriorated. In this case, it is only necessary to intentionally slip the HC from the DOC 15 by increasing the injection amount of the exhaust pipe injection (or post injection). Further, the engine 10 is not limited to a diesel engine, and can be widely applied to other internal combustion engines such as a gasoline engine.
　１０　エンジン
　１３　排気管内噴射装置（供給手段）
　１５　ＤＯＣ（酸化触媒）
　１６　ＤＰＦ（フィルタ）
　４０　ＥＣＵ
　４１　ＤＯＣ発熱率演算部（第１発熱量推定手段）
　４２　ＤＯＣ劣化判定部（判定手段）
　４３　ＨＣスリップ量演算部（スリップ量演算手段）
　４４　ＤＰＦ発熱率演算部（第２発熱量推定手段）
　４５　ＤＰＦ劣化判定部（判定手段） 10 Engine 13 Exhaust pipe injection device (supply means)
15 DOC (oxidation catalyst)
16 DPF (filter)
40 ECU
41 DOC heat generation rate calculation unit (first heat generation amount estimation means)
42 DOC deterioration determination unit (determination means)
43 HC slip amount calculation unit (slip amount calculation means)
44 DPF heat generation rate calculation section (second heat generation amount estimation means)
45 DPF degradation determination unit (determination means)

Claims (4)

  1. 　内燃機関の排気系に設けられて、排気中に含まれる少なくとも炭化水素を酸化する酸化触媒と、
    　前記酸化触媒の排気下流側に設けられて、排気中に含まれる粒子状物質を捕集するフィルタと、
    　前記酸化触媒に炭化水素を供給可能な供給手段と、
    　少なくとも前記酸化触媒の入口排気温度、出口排気温度、外気温度及び、前記供給手段から供給される炭化水素供給量に基づいて、外気への熱損失量を考慮した前記酸化触媒内での炭化水素発熱率を演算する第１発熱率演算手段と、
    　演算された前記酸化触媒内での炭化水素発熱率及び、前記炭化水素供給量に基づいて、前記酸化触媒を通過する未燃焼の炭化水素スリップ量を演算するスリップ量演算手段と、
    　少なくとも前記フィルタの入口排気温度、出口排気温度、外気温度及び、演算された前記炭化水素スリップ量に基づいて、外気への熱損失量を考慮した前記フィルタ内での炭化水素発熱率を演算する第２発熱率演算手段と、
    　演算された前記フィルタ内での炭化水素発熱率に基づいて、前記フィルタの劣化を判定する判定手段と、を備える
    　ことを特徴とする診断装置。     An oxidation catalyst provided in an exhaust system of an internal combustion engine for oxidizing at least hydrocarbons contained in the exhaust;
    A filter provided on the exhaust downstream side of the oxidation catalyst for collecting particulate matter contained in the exhaust;
    Supply means capable of supplying hydrocarbons to the oxidation catalyst;
    Hydrocarbon heat generation in the oxidation catalyst taking into account the amount of heat loss to the outside air based on at least the inlet exhaust temperature, the outlet exhaust temperature, the outside air temperature of the oxidation catalyst, and the amount of hydrocarbons supplied from the supply means First heat rate calculating means for calculating a rate;
    Slip amount calculating means for calculating the amount of unburned hydrocarbon slip passing through the oxidation catalyst based on the calculated hydrocarbon heat generation rate in the oxidation catalyst and the amount of hydrocarbon supply;
    Calculating a hydrocarbon heat generation rate in the filter in consideration of an amount of heat loss to the outside air based on at least the inlet exhaust temperature, the outlet exhaust temperature, the outside air temperature, and the calculated amount of the hydrocarbon slip of the filter; 2 heating rate calculation means;
    And a determination unit that determines deterioration of the filter based on the calculated hydrocarbon heat generation rate in the filter.
  2. 　前記第１及び第２発熱率演算手段は、自然対流の熱伝達率を含む第１モデル式及び、強制対流の熱伝達率を含む第２モデル式に基づいて前記熱損失量を演算する
    　請求項１に記載の診断装置。     The first and second heat generation rate calculation means calculate the amount of heat loss based on a first model expression including a natural convection heat transfer coefficient and a second model expression including a forced convection heat transfer coefficient. The diagnostic apparatus according to 1.
  3. 　前記酸化触媒及び前記フィルタは、車体下部に設けられる筒状の触媒ケース内に収容され、
    　前記強制対流の熱伝達率は、強制対流を前記触媒ケースの下面に影響する平板上の乱流と仮定したヌセルト数に基づいて設定される
    　請求項２に記載の診断装置。     The oxidation catalyst and the filter are accommodated in a cylindrical catalyst case provided at the lower part of the vehicle body,
    The diagnostic device according to claim 2, wherein the heat transfer coefficient of the forced convection is set based on a Nusselt number on the assumption that the forced convection is a turbulent flow on a flat plate that affects the lower surface of the catalyst case.
  4. 　前記判定手段は、さらに、演算された前記酸化触媒内での炭化水素発熱率に基づいて、前記酸化触媒の劣化を判定する
    　請求項１から３の何れか一項に記載の診断装置。     The diagnostic device according to any one of claims 1 to 3, wherein the determination unit further determines deterioration of the oxidation catalyst based on the calculated hydrocarbon heat generation rate in the oxidation catalyst.
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JP2018003703A (en) * 2016-07-04 2018-01-11 日立オートモティブシステムズ株式会社 Device for controlling internal combustion engine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003106140A (en) * 2001-06-22 2003-04-09 Denso Corp Catalyst deterioration detecting device
JP2004138014A (en) * 2002-10-21 2004-05-13 Mazda Motor Corp Vehicular mounting structure for exhaust system equipped with exhaust particulate removing device
JP2005351153A (en) * 2004-06-10 2005-12-22 Toyota Motor Corp Catalytic deterioration determining device
JP2009162177A (en) * 2008-01-09 2009-07-23 Toshiba Corp Steam valve and power generation unit
JP2010112220A (en) * 2008-11-05 2010-05-20 Nissan Motor Co Ltd Catalyst diagnostic device
JP2013068186A (en) * 2011-09-26 2013-04-18 Kubota Corp Diesel engine

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003106140A (en) * 2001-06-22 2003-04-09 Denso Corp Catalyst deterioration detecting device
JP2004138014A (en) * 2002-10-21 2004-05-13 Mazda Motor Corp Vehicular mounting structure for exhaust system equipped with exhaust particulate removing device
JP2005351153A (en) * 2004-06-10 2005-12-22 Toyota Motor Corp Catalytic deterioration determining device
JP2009162177A (en) * 2008-01-09 2009-07-23 Toshiba Corp Steam valve and power generation unit
JP2010112220A (en) * 2008-11-05 2010-05-20 Nissan Motor Co Ltd Catalyst diagnostic device
JP2013068186A (en) * 2011-09-26 2013-04-18 Kubota Corp Diesel engine

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