WO2022014388A1 - Control device for internal combustion engine - Google Patents

Control device for internal combustion engine Download PDF

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Publication number
WO2022014388A1
WO2022014388A1 PCT/JP2021/025265 JP2021025265W WO2022014388A1 WO 2022014388 A1 WO2022014388 A1 WO 2022014388A1 JP 2021025265 W JP2021025265 W JP 2021025265W WO 2022014388 A1 WO2022014388 A1 WO 2022014388A1
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WO
WIPO (PCT)
Prior art keywords
control mode
intake
amount
internal combustion
value
Prior art date
Application number
PCT/JP2021/025265
Other languages
French (fr)
Japanese (ja)
Inventor
敦 岡崎
Original Assignee
いすゞ自動車株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by いすゞ自動車株式会社 filed Critical いすゞ自動車株式会社
Priority to CN202180039392.0A priority Critical patent/CN115698491A/en
Publication of WO2022014388A1 publication Critical patent/WO2022014388A1/en

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Classifications

    • 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
    • F01N3/24—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 characterised by constructional aspects of converting apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D21/00—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas
    • F02D21/06—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas peculiar to engines having other non-fuel gas added to combustion air
    • F02D21/08—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas peculiar to engines having other non-fuel gas added to combustion air the other gas being the exhaust gas of engine
    • 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
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D43/00—Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/02—EGR systems specially adapted for supercharged engines
    • F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
    • F02M26/05—High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/52—Systems for actuating EGR valves
    • F02M26/53—Systems for actuating EGR valves using electric actuators, e.g. solenoids
    • 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 control device for an internal combustion engine.
  • the internal combustion engine mounted on the vehicle has an EGR device for recirculating a part of the exhaust gas.
  • the EGR device adjusts, for example, the opening degree of a valve provided in the EGR passage to adjust the amount of exhaust gas recirculated to the internal combustion engine. Further, the EGR device controls to adjust the valve opening degree based on the intake amount of the intake air of the internal combustion engine and the emission amount of NOx in order to suppress the emission amount of NOx in the exhaust gas (hereinafter referred to as EGR control). Call).
  • an aftertreatment device for example, a catalyst for purifying the exhaust gas is provided in the exhaust passage, and a temperature rise control mode for raising the temperature of the catalyst is executed in order to activate the catalyst.
  • the characteristics of intake and exhaust in the temperature rise control mode are different from the characteristics of intake and exhaust in the normal control mode other than the temperature rise control mode. Therefore, if EGR control similar to that in the normal control mode is performed in the temperature rise control mode, NOx emission may not be appropriately suppressed.
  • the present invention has been made in view of these points, and an object thereof is to perform EGR control with high accuracy in different control modes.
  • the control mode of the internal combustion engine is a temperature rise control mode for raising the temperature of the aftertreatment device for purifying the exhaust gas of the internal combustion engine or a normal control mode other than the temperature rise control mode.
  • the mode determination unit for determination and, when the normal control mode is determined, estimate the first intake amount, which is the intake amount of the internal combustion engine, using the first value of the intake parameter, and use the temperature rise control mode. If it is determined, the intake amount estimation unit that estimates the second intake amount using a second value different from the first value of the intake parameter, and if it is determined to be the normal control mode, the exhaust gas is discharged.
  • the first emission amount which is the NOx emission amount in the exhaust gas
  • the first value of the parameter is estimated using the first value of the parameter, and when the temperature rise control mode is determined, the first value different from the first value of the exhaust parameter is determined.
  • the NOx estimation unit that estimates the second emission amount using two values
  • the intake amount and NOx emission amount estimated by the intake amount estimation unit and the NOx estimation unit according to the control mode determined by the mode determination unit.
  • an internal combustion engine control device including an EGR control unit that controls an EGR device that recirculates a part of the exhaust gas.
  • the intake amount estimation unit estimates the first intake amount using the first value of the estimated volumetric efficiency of the internal combustion engine main body, and the second value smaller than the first value of the estimated volume efficiency is used. 2
  • the intake amount may be estimated.
  • the intake intake amount estimation unit estimates the first intake amount using the first value of the estimated volumetric efficiency obtained by using the rotation speed of the internal combustion engine main body and the fuel injection amount, and the estimated volumetric efficiency.
  • the second intake amount may be estimated using the second value.
  • the NOx estimation unit estimates the first emission amount using the first value of the environmental condition coefficient indicating the combustion state of the internal combustion engine main body, and uses the second value smaller than the first value of the environmental condition coefficient.
  • the second emission amount may be estimated.
  • the NOx estimation unit estimates the first emission amount using the first value of the environmental condition coefficient obtained by using the fuel injection timing, the temperature of the cooling water, and the temperature of the intake air, and the NOx estimation unit estimates the first emission amount of the environmental condition coefficient.
  • the second value may be used to estimate the second emission amount.
  • the mode determination unit may determine whether or not the temperature rise control mode is based on the temperature of the cooling water for cooling the internal combustion engine and the temperature of the exhaust gas. Further, when the temperature of the cooling water and the temperature of the exhaust gas are higher than the predetermined values, the mode determination unit determines that the temperature rise control mode is used, and determines that the temperature of the cooling water and the exhaust gas are higher than the predetermined values. When the temperature is lower than the predetermined value, it may be determined that the normal control mode is used.
  • FIG. 1 is a schematic diagram for explaining the configuration of the internal combustion engine 1 according to the embodiment.
  • the internal combustion engine 1 is, for example, a multi-cylinder engine mounted on a vehicle such as a truck.
  • the internal combustion engine 1 is a diesel engine, but is not limited to this, and may be, for example, a gasoline engine.
  • the internal combustion engine 1 includes an engine main body 10, a fuel injection device 15, an intake passage 20, an exhaust passage 30, a turbocharger 40, an EGR device 50, and a control device 100.
  • the engine body 10 has four cylinders 12 here, but is not limited thereto. Movable parts such as pistons and crankshafts are provided in each cylinder 12.
  • the fuel injection device 15 is an injection device that injects fuel into the combustion chamber in the engine body 10.
  • the fuel injection device 15 is a common rail type fuel injection device here, and has an injector 16 and a common rail 17.
  • the injector 16 injects fuel into the combustion chamber in each cylinder 12.
  • the common rail 17 stores the fuel injected from the injector 16 in a high pressure state.
  • the intake passage 20 is a passage through which intake air to be sucked into the engine body 10 flows.
  • the intake passage 20 has an intake manifold 22 connected to the engine body 10 and an intake pipe 23 connected to the upstream end of the intake manifold 22.
  • the intake manifold 22 distributes and supplies the intake air sent from the intake pipe 23 to the intake ports of each cylinder.
  • the intake pipe 23 is provided with an air cleaner 24, an air flow meter 25, a compressor 42C of a turbocharger 40, an intercooler 27, and an intake throttle valve 28.
  • the air flow meter 25 detects the amount of intake air per unit time of the internal combustion engine 1, that is, the intake flow rate.
  • the exhaust passage 30 is a passage through which the exhaust gas generated from the engine body 10 flows.
  • the exhaust passage 30 has an exhaust manifold 32 connected to the engine body 10 and an exhaust pipe 33 connected to the downstream end of the exhaust manifold 32.
  • the exhaust manifold 32 collects the exhaust gas sent from the exhaust port of each cylinder.
  • the exhaust pipe 33 is provided with a turbine 42T of the turbocharger 40 and an aftertreatment device 35.
  • the aftertreatment device 35 is a device for purifying the exhaust gas, and includes, for example, an oxidation catalyst, a DPF, an SCR, and an ammonia oxidation catalyst.
  • a control mode for raising the temperature of the aftertreatment device 35 (specifically, the catalyst) at an early stage from the cold start of the internal combustion engine 1 to the completion of warming up (hereinafter referred to as a temperature rise control mode).
  • the characteristics of intake and exhaust in the temperature rise control mode are different from the characteristics of intake and exhaust in the normal control mode other than the temperature rise control mode.
  • the turbocharger 40 is a supercharger that compresses the intake air flowing through the intake passage 20 by utilizing the flow of exhaust gas flowing through the exhaust passage 30.
  • the turbocharger 40 has a turbine 42T provided in the exhaust passage 30 and a compressor 42C provided in the intake passage 20.
  • the turbine 42T is located on the engine body 10 side of the aftertreatment device 35 in the exhaust passage 30.
  • the EGR device 50 recirculates a part of the exhaust gas to the engine body 10. Specifically, the EGR device 50 uses a part of the exhaust gas (hereinafter referred to as EGR gas) in the exhaust passage 30 (here, the exhaust manifold 32) in the intake passage 20 (here, the intake manifold 22). (Inside).
  • EGR gas a part of the exhaust gas
  • the EGR device 50 includes an EGR passage 52, an EGR cooler 53, an EGR valve 54, and a temperature sensor 55.
  • the EGR passage 52 is a flow path through which EGR gas flows.
  • the EGR cooler 53 is provided in the EGR passage 52 and cools the EGR gas.
  • the EGR valve 54 is a valve that can be opened and closed, and regulates the flow rate of EGR gas.
  • the temperature sensor 55 detects the temperature of the EGR gas flowing through the EGR passage 52.
  • the control device 100 controls the operation of the entire internal combustion engine 1.
  • the control device 100 executes the above-mentioned temperature rise control mode and the normal control mode other than the temperature rise control mode as the control mode of the internal combustion engine 1. Further, the control device 100 controls to adjust the opening degree of the EGR valve 54 based on the intake amount and the NOx emission amount of the intake air of the internal combustion engine 1 in order to suppress the emission amount of NOx in the exhaust gas (also referred to as EGR control). Call). Then, although the details will be described later, the control device 100 estimates the intake air amount and the NOx emission amount according to the control mode, and performs EGR control based on the estimated intake air amount and the NOx emission amount. As a result, EGR control can be performed with high accuracy in the temperature rise control mode and the normal control mode in which the intake and exhaust characteristics are different.
  • control device 100 The detailed configuration of the control device 100 will be described with reference to FIG.
  • FIG. 2 is a schematic diagram for explaining the detailed configuration of the control device 100.
  • the control device 100 has a storage unit 110 and a control unit 120.
  • the storage unit 110 includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory).
  • the storage unit 110 stores programs and various data for execution by the control unit 120.
  • the control unit 120 is, for example, a CPU (Central Processing Unit).
  • the control unit 120 controls the operation of the internal combustion engine 1 by executing the program stored in the storage unit 110.
  • the control unit 120 functions as a mode determination unit 122, an intake air amount estimation unit 123, a NOx estimation unit 124, and an EGR control unit 125.
  • the mode determination unit 122 determines the control mode of the internal combustion engine 1. For example, the mode determination unit 122 determines whether the control mode is the temperature rise control mode or the normal control mode.
  • the temperature rise control mode is a control mode for raising the temperature of the aftertreatment device 35 at an early stage from the cold start of the internal combustion engine 1 to the completion of warming up.
  • the normal control mode is a control mode other than the temperature rise control mode.
  • the mode determination unit 122 outputs the determination result to the intake air amount estimation unit 123 and the NOx estimation unit 124.
  • the mode determination unit 122 determines the control mode based on the state of the internal combustion engine 1 detected by the detection sensor group 70.
  • the mode determination unit 122 may determine the control mode based on the temperature of the cooling water for cooling the internal combustion engine 1 and the temperature of the exhaust gas. For example, when the temperature of the cooling water and the temperature of the exhaust gas are higher than the predetermined values, the mode determination unit 122 determines that the temperature rise control mode is used, and the temperature of the cooling water and the temperature of the exhaust gas are predetermined respectively. If it is lower than the value, it is determined that the control mode is normal.
  • the mode determination unit 122 may determine by including another parameter (for example, atmospheric pressure) in addition to the temperature of the cooling water and the temperature of the exhaust gas.
  • the intake air amount estimation unit 123 estimates the intake air amount of the internal combustion engine 1.
  • the intake air amount estimation unit 123 estimates the intake air amount according to the control mode determined by the mode determination unit 122.
  • the intake amount estimation unit 123 estimates the normal intake amount, which is the intake amount in the normal control mode.
  • the intake air amount estimation unit 123 estimates the intake air amount at the time of temperature rise, which is the intake amount in the temperature rise control mode.
  • the normal intake amount corresponds to the first intake amount
  • the temperature rise intake amount corresponds to the second intake amount.
  • the intake air amount is obtained by the product of the estimated volumetric efficiency, which is an intake air parameter, and the estimated intake air amount.
  • the estimated volumetric efficiency and the estimated intake air amount can be obtained by a known calculation method.
  • the estimated volumetric efficiency can be obtained by using the rotation speed of the engine body 10 and the fuel injection amount.
  • the estimated intake air amount can be obtained by using the pressure, temperature, and volume in the cylinder 12 of the intake manifold 22.
  • the value of the estimated volumetric efficiency when calculating the normal intake air amount (hereinafter, the first value) and the value of the estimated volumetric efficiency when calculating the heat intake amount at the time of temperature rise (hereinafter, the second value) are set. different.
  • the second value of the estimated volumetric efficiency at the time of obtaining the intake amount at the time of temperature rise is the estimated volumetric efficiency at the time of obtaining the normal time intake amount. It is smaller than the first value. Therefore, the intake air amount at the time of temperature rise estimated by the intake air amount estimation unit 123 is smaller than the normal intake air amount.
  • the NOx estimation unit 124 estimates the amount of NOx emissions.
  • the NOx estimation unit 124 estimates the emission amount according to the control mode determined by the mode determination unit 122.
  • the NOx estimation unit 124 estimates the normal emission amount, which is the emission amount in the normal control mode.
  • the NOx estimation unit 124 estimates the discharge amount at the time of temperature rise, which is the discharge amount in the temperature rise control mode.
  • the normal emission amount corresponds to the first emission amount
  • the temperature rising emission amount corresponds to the second emission amount.
  • the NOx emission amount is obtained by the product of the rotation speed of the engine body 10, the fuel injection amount, and the environmental condition coefficient.
  • the environmental condition coefficient indicates the combustion state in the engine body 10, and corresponds to the emission parameter.
  • the environmental condition coefficient can be obtained by using, for example, the fuel injection timing, the temperature of the cooling water, the temperature of the intake air, and the like.
  • the value of the environmental condition coefficient (hereinafter, the first value) when calculating the emission amount at the normal time and the value of the environmental condition coefficient (hereinafter, the second value) at the time of calculating the emission amount at the time of temperature rise are used. different.
  • the second value of the environmental condition coefficient when calculating the emission amount at the time of temperature rise is the environment when the emission amount at the normal time is calculated. It is smaller than the first value of the condition coefficient. Therefore, the emission amount at the time of temperature rise estimated by the NOx estimation unit 124 is smaller than the emission amount at the normal time.
  • the EGR control unit 125 controls the operation of the EGR device 50.
  • the EGR control unit 125 controls the opening / closing (EGR control) of the EGR valve 54 of the EGR device 50.
  • the EGR control unit 125 controls the operation of the EGR device 50 based on the estimated values of the intake air amount estimation unit 123 and the NOx estimation unit 124.
  • the EGR control unit 125 uses the EGR device 50 based on the intake air amount and the NOx emission amount estimated by the intake air amount estimation unit 123 and the NOx estimation unit 124 according to the control mode determined by the mode determination unit 122. Control. That is, in the normal control mode, the EGR control unit 125 uses the normal intake amount estimated by the intake amount estimation unit 123 and the normal discharge amount estimated by the NOx estimation unit 124, and the EGR valve 54 Controls the opening and closing of. On the other hand, in the case of the temperature rise control mode, the EGR control unit 125 uses the intake air amount at temperature temperature estimated by the intake air amount estimation unit 123 and the discharge amount at temperature temperature estimated by the NOx estimation unit 124. , Controls the opening and closing of the EGR valve 54.
  • FIG. 3 is a flowchart for explaining an operation example of the internal combustion engine 1. This flowchart starts from the place where the internal combustion engine 1 is operating. Along with this, the exhaust gas generated from the engine body 10 is flowing through the exhaust passage 30.
  • the mode determination unit 122 determines the control mode of the internal combustion engine 1 (step S102). Specifically, the mode determination unit 122 determines whether the control mode is the temperature rise control mode or the normal control mode.
  • step S104 determines that the temperature rise control mode is set (step S104: Yes)
  • the intake air amount estimation unit 123 estimates the intake air amount at the time of temperature rise, which is the intake air amount in the temperature rise control mode (step S104: Yes).
  • Step S106 estimates the intake air amount at the time of temperature rise, which is the intake air amount in the temperature rise control mode (step S104: Yes).
  • the NOx estimation unit 124 estimates the amount of NOx discharged at the time of temperature rise, which is the amount of NOx discharged in the temperature rise control mode (step S108).
  • the processing of step S106 and the processing of step S108 may be performed in the reverse order or may be performed at the same time.
  • the EGR control unit 125 opens and closes the EGR valve 54 of the EGR device 50 based on the intake air amount at the time of temperature rise estimated by the intake air amount estimation unit 123 and the discharge amount at the time of temperature rise estimated by the NOx estimation unit 124. Is controlled (step S110). For example, the EGR control unit 125 controls the opening degree of the EGR valve 54.
  • the intake amount estimation unit 123 estimates the normal intake amount, which is the intake amount in the normal control mode (step S112). .. Further, the NOx estimation unit 124 estimates the normal emission amount, which is the NOx emission amount in the normal control mode (step S114).
  • the EGR control unit 125 controls the opening and closing of the EGR valve 54 based on the normal intake amount estimated by the intake amount estimation unit 123 and the normal discharge amount estimated by the NOx estimation unit 124 (step S116). ). For example, the EGR control unit 125 controls the opening degree of the EGR valve 54.
  • the control device 100 of the internal combustion engine 1 of the above-described embodiment has an intake amount (first intake amount) and NOx emission amount (first emission amount) in the normal control mode and an intake amount (first) in the temperature rise control mode.
  • the intake amount) and the NOx emission amount (first emission amount) are estimated using different values.
  • the control device 100 controls the operation of the EGR device 50 based on the intake amount and the NOx discharge amount estimated according to the control mode.
  • the intake amount and NOx emission amount in the normal control mode and the intake amount and NOx emission amount in the temperature rise control mode can be estimated with high accuracy. Therefore, EGR control based on the intake amount and the NOx emission amount can be performed with high accuracy in the normal control mode and the temperature rise control mode.

Abstract

This control device comprises: a mode determination unit 122 that determines whether a control mode of an internal combustion engine is a temperature rise control mode and a normal control mode; an intake amount estimation unit 123 that estimates a first intake amount using a first value of an intake parameter when it is determined that the control mode is the normal control mode, and estimates a second intake amount using a second value of the intake parameter different from the first value when it is determined that the control mode is the temperature rise control mode; a NOx estimation unit 124 that estimates a first discharge amount using a first value of a discharge parameter when it is determined that the control mode is the normal control mode, and estimates a second discharge amount using a second value of the discharge parameter different from the first value when it is determined that the control mode is the temperature rise control mode; and an EGR control unit 125 that controls an EGR device for recirculating part of exhaust gas on the basis of the intake amounts and the NOx discharge amounts estimated by the intake amount estimation unit 123 and the NOx estimation unit 124 according to the control mode determined by the mode determination unit 122.

Description

内燃機関の制御装置Internal combustion engine control device
　本発明は、内燃機関の制御装置に関する。 The present invention relates to a control device for an internal combustion engine.
　車両に搭載された内燃機関は、排気ガスの一部を還流させるためのＥＧＲ装置を有する。ＥＧＲ装置は、例えば、ＥＧＲ通路に設けられた弁の開度を調整して、内燃機関へ還流させる排気ガスの量を調整する。また、ＥＧＲ装置は、排気ガス中のＮＯｘの排出量を抑制すべく、内燃機関の吸気の吸気量とＮＯｘの排出量とに基づいて、弁の開度を調整する制御（以下、ＥＧＲ制御と呼ぶ）を行っている。 The internal combustion engine mounted on the vehicle has an EGR device for recirculating a part of the exhaust gas. The EGR device adjusts, for example, the opening degree of a valve provided in the EGR passage to adjust the amount of exhaust gas recirculated to the internal combustion engine. Further, the EGR device controls to adjust the valve opening degree based on the intake amount of the intake air of the internal combustion engine and the emission amount of NOx in order to suppress the emission amount of NOx in the exhaust gas (hereinafter referred to as EGR control). Call).
特開２００８－２１５２１０号公報Japanese Unexamined Patent Publication No. 2008-215210
　ところで、排気通路には、排気ガスを浄化する後処理装置（例えば、触媒）が設けられており、当該触媒を活性化させるために、触媒を昇温させる昇温制御モードが実行される。昇温制御モード時の吸排気の特性は、昇温制御モード以外の通常制御モード時の吸排気の特性と異なる。このため、昇温制御モード時に、通常制御モード時と同様なＥＧＲ制御を行うと、ＮＯｘの排出を適切に抑制できないおそれがある。 By the way, an aftertreatment device (for example, a catalyst) for purifying the exhaust gas is provided in the exhaust passage, and a temperature rise control mode for raising the temperature of the catalyst is executed in order to activate the catalyst. The characteristics of intake and exhaust in the temperature rise control mode are different from the characteristics of intake and exhaust in the normal control mode other than the temperature rise control mode. Therefore, if EGR control similar to that in the normal control mode is performed in the temperature rise control mode, NOx emission may not be appropriately suppressed.
　そこで、本発明はこれらの点に鑑みてなされたものであり、異なる制御モード時にＥＧＲ制御を高精度に行うことを目的とする。 Therefore, the present invention has been made in view of these points, and an object thereof is to perform EGR control with high accuracy in different control modes.
　本発明の一の態様においては、内燃機関の制御モードが、前記内燃機関の排気ガスを浄化する後処理装置を昇温させる昇温制御モードか、前記昇温制御モード以外の通常制御モードかを判定するモード判定部と、前記通常制御モードと判定された場合には、吸気パラメータの第１値を用いて前記内燃機関の吸気量である第１吸気量を推定し、前記昇温制御モードと判定された場合には、前記吸気パラメータの前記第１値とは異なる第２値を用いて第２吸気量を推定する吸気量推定部と、前記通常制御モードと判定された場合には、排出パラメータの第１値を用いて前記排気ガス中のＮＯｘ排出量である第１排出量を推定し、前記昇温制御モードと判定された場合には、前記排出パラメータの第１値とは異なる第２値を用いて第２排出量を推定するＮＯｘ推定部と、前記モード判定部が判定した制御モードに応じて前記吸気量推定部及びＮＯｘ推定部が推定した吸気量及びＮＯｘ排出量に基づいて、前記排気ガスの一部を還流させるＥＧＲ装置を制御するＥＧＲ制御部と、を備える、内燃機関の制御装置を提供する。 In one aspect of the present invention, whether the control mode of the internal combustion engine is a temperature rise control mode for raising the temperature of the aftertreatment device for purifying the exhaust gas of the internal combustion engine or a normal control mode other than the temperature rise control mode. The mode determination unit for determination and, when the normal control mode is determined, estimate the first intake amount, which is the intake amount of the internal combustion engine, using the first value of the intake parameter, and use the temperature rise control mode. If it is determined, the intake amount estimation unit that estimates the second intake amount using a second value different from the first value of the intake parameter, and if it is determined to be the normal control mode, the exhaust gas is discharged. The first emission amount, which is the NOx emission amount in the exhaust gas, is estimated using the first value of the parameter, and when the temperature rise control mode is determined, the first value different from the first value of the exhaust parameter is determined. Based on the NOx estimation unit that estimates the second emission amount using two values, and the intake amount and NOx emission amount estimated by the intake amount estimation unit and the NOx estimation unit according to the control mode determined by the mode determination unit. Provided is an internal combustion engine control device including an EGR control unit that controls an EGR device that recirculates a part of the exhaust gas.
　また、前記吸気量推定部は、内燃機関本体の推定体積効率の第１値を用いて前記第１吸気量を推定し、前記推定体積効率の第１値より小さい第２値を用いて前記第２吸気量を推定することとしてもよい。
　また、前記吸気量推定部は、前記内燃機関本体の回転数及び燃料噴射量を用いて求まる前記推定体積効率の前記第１値を用いて前記第１吸気量を推定し、前記推定体積効率の前記第２値を用いて前記第２吸気量を推定することとしてもよい。 Further, the intake amount estimation unit estimates the first intake amount using the first value of the estimated volumetric efficiency of the internal combustion engine main body, and the second value smaller than the first value of the estimated volume efficiency is used. 2 The intake amount may be estimated.
Further, the intake intake amount estimation unit estimates the first intake amount using the first value of the estimated volumetric efficiency obtained by using the rotation speed of the internal combustion engine main body and the fuel injection amount, and the estimated volumetric efficiency. The second intake amount may be estimated using the second value.
　また、前記ＮＯｘ推定部は、内燃機関本体の燃焼状態を示す環境条件係数の第１値を用いて前記第１排出量を推定し、前記環境条件係数の第１値より小さい第２値を用いて前記第２排出量を推定することとしてもよい。
　また、前記ＮＯｘ推定部は、燃料噴射タイミング、冷却水の温度及び吸気の温度を用いて求まる前記環境条件係数の第１値を用いて前記第１排出量を推定し、前記環境条件係数の前記第２値を用いて前記第２排出量を推定することとしてもよい。 Further, the NOx estimation unit estimates the first emission amount using the first value of the environmental condition coefficient indicating the combustion state of the internal combustion engine main body, and uses the second value smaller than the first value of the environmental condition coefficient. The second emission amount may be estimated.
Further, the NOx estimation unit estimates the first emission amount using the first value of the environmental condition coefficient obtained by using the fuel injection timing, the temperature of the cooling water, and the temperature of the intake air, and the NOx estimation unit estimates the first emission amount of the environmental condition coefficient. The second value may be used to estimate the second emission amount.
　また、前記モード判定部は、前記内燃機関を冷却する冷却水の温度と、前記排気ガスの温度とに基づいて、前記昇温制御モードか否かを判定することとしてもよい。
　また、前記モード判定部は、前記冷却水の温度及び前記排気ガスの温度が所定値よりも高い場合には、前記昇温制御モードであると判定し、前記冷却水の温度及び前記排気ガスの温度が前記所定値よりも低い場合には、前記通常制御モードであると判定することとしてもよい。 Further, the mode determination unit may determine whether or not the temperature rise control mode is based on the temperature of the cooling water for cooling the internal combustion engine and the temperature of the exhaust gas.
Further, when the temperature of the cooling water and the temperature of the exhaust gas are higher than the predetermined values, the mode determination unit determines that the temperature rise control mode is used, and determines that the temperature of the cooling water and the exhaust gas are higher than the predetermined values. When the temperature is lower than the predetermined value, it may be determined that the normal control mode is used.
　本発明によれば、異なる制御モード時にＥＧＲ制御を高精度に行えるという効果を奏する。 According to the present invention, there is an effect that EGR control can be performed with high accuracy in different control modes.
一の実施形態に係る内燃機関１の構成を説明するための模式図である。It is a schematic diagram for demonstrating the structure of the internal combustion engine 1 which concerns on one Embodiment. 制御装置１００の詳細構成を説明するための模式図である。It is a schematic diagram for demonstrating the detailed structure of a control device 100. 内燃機関１の動作例を説明するためのフローチャートである。It is a flowchart for demonstrating the operation example of the internal combustion engine 1.
　＜内燃機関の構成＞
　本発明の一の実施形態に係る内燃機関の構成について、図１を参照しながら説明する。 <Composition of internal combustion engine>
The configuration of the internal combustion engine according to the embodiment of the present invention will be described with reference to FIG.
　図１は、一の実施形態に係る内燃機関１の構成を説明するための模式図である。内燃機関１は、例えば、トラック等の車両に搭載された多気筒エンジンである。内燃機関１は、ディーゼルエンジンであるが、これに限定されず、例えばガソリンエンジンであってもよい。内燃機関１は、図１に示すように、エンジン本体１０と、燃料噴射装置１５と、吸気通路２０と、排気通路３０と、ターボチャージャ４０と、ＥＧＲ装置５０と、制御装置１００とを有する。 FIG. 1 is a schematic diagram for explaining the configuration of the internal combustion engine 1 according to the embodiment. The internal combustion engine 1 is, for example, a multi-cylinder engine mounted on a vehicle such as a truck. The internal combustion engine 1 is a diesel engine, but is not limited to this, and may be, for example, a gasoline engine. As shown in FIG. 1, the internal combustion engine 1 includes an engine main body 10, a fuel injection device 15, an intake passage 20, an exhaust passage 30, a turbocharger 40, an EGR device 50, and a control device 100.
　エンジン本体１０は、ここでは４つのシリンダ１２を有するが、これに限定されない。各シリンダ１２内には、ピストン、クランクシャフト等の可動部品が設けられている。 The engine body 10 has four cylinders 12 here, but is not limited thereto. Movable parts such as pistons and crankshafts are provided in each cylinder 12.
　燃料噴射装置１５は、エンジン本体１０内の燃焼室に燃料を噴射する噴射装置である。燃料噴射装置１５は、ここではコモンレール式燃料噴射装置であり、インジェクタ１６とコモンレール１７を有する。インジェクタ１６は、各シリンダ１２内の燃焼室に燃料を噴射する。コモンレール１７は、インジェクタ１６から噴射される燃料を高圧状態で貯留する。 The fuel injection device 15 is an injection device that injects fuel into the combustion chamber in the engine body 10. The fuel injection device 15 is a common rail type fuel injection device here, and has an injector 16 and a common rail 17. The injector 16 injects fuel into the combustion chamber in each cylinder 12. The common rail 17 stores the fuel injected from the injector 16 in a high pressure state.
　吸気通路２０は、エンジン本体１０に吸入する吸気が流れる通路である。吸気通路２０は、エンジン本体１０に接続された吸気マニホールド２２と、吸気マニホールド２２の上流端に接続された吸気管２３とを有する。吸気マニホールド２２は、吸気管２３から送られてきた吸気を各気筒の吸気ポートに分配供給する。吸気管２３には、エアクリーナ２４、エアフローメータ２５、ターボチャージャ４０のコンプレッサ４２Ｃ、インタークーラ２７、吸気絞り弁２８が設けられている。エアフローメータ２５は、内燃機関１の単位時間当たりの吸入空気量すなわち吸気流量を検出する。 The intake passage 20 is a passage through which intake air to be sucked into the engine body 10 flows. The intake passage 20 has an intake manifold 22 connected to the engine body 10 and an intake pipe 23 connected to the upstream end of the intake manifold 22. The intake manifold 22 distributes and supplies the intake air sent from the intake pipe 23 to the intake ports of each cylinder. The intake pipe 23 is provided with an air cleaner 24, an air flow meter 25, a compressor 42C of a turbocharger 40, an intercooler 27, and an intake throttle valve 28. The air flow meter 25 detects the amount of intake air per unit time of the internal combustion engine 1, that is, the intake flow rate.
　排気通路３０は、エンジン本体１０から発生する排気ガスが流れる通路である。排気通路３０は、エンジン本体１０に接続された排気マニホールド３２と、排気マニホールド３２の下流端に接続された排気管３３とを有する。排気マニホールド３２は、各気筒の排気ポートから送られてきた排気ガスを集合する。排気管３３には、ターボチャージャ４０のタービン４２Ｔ、後処理装置３５が設けられている。後処理装置３５は、排気ガスを浄化するための装置であり、例えば、酸化触媒、ＤＰＦ、ＳＣＲ、アンモニア酸化触媒を含む。 The exhaust passage 30 is a passage through which the exhaust gas generated from the engine body 10 flows. The exhaust passage 30 has an exhaust manifold 32 connected to the engine body 10 and an exhaust pipe 33 connected to the downstream end of the exhaust manifold 32. The exhaust manifold 32 collects the exhaust gas sent from the exhaust port of each cylinder. The exhaust pipe 33 is provided with a turbine 42T of the turbocharger 40 and an aftertreatment device 35. The aftertreatment device 35 is a device for purifying the exhaust gas, and includes, for example, an oxidation catalyst, a DPF, an SCR, and an ammonia oxidation catalyst.
　ところで、内燃機関１の冷間始動後から暖機完了までの間、後処理装置３５（具体的には、触媒）を早期に昇温させるための制御モード（以下、昇温制御モードと呼ぶ）を実行可能となっている。昇温制御モード時の吸排気の特性は、昇温制御モード以外の通常制御モード時の吸排気の特性と異なる。 By the way, a control mode for raising the temperature of the aftertreatment device 35 (specifically, the catalyst) at an early stage from the cold start of the internal combustion engine 1 to the completion of warming up (hereinafter referred to as a temperature rise control mode). Is feasible. The characteristics of intake and exhaust in the temperature rise control mode are different from the characteristics of intake and exhaust in the normal control mode other than the temperature rise control mode.
　ターボチャージャ４０は、排気通路３０を流れる排気ガスの流れを利用して、吸気通路２０を流れる吸気を圧縮する過給機である。ターボチャージャ４０は、排気通路３０に設けられたタービン４２Ｔと、吸気通路２０に設けられたコンプレッサ４２Ｃとを有する。タービン４２Ｔは、排気通路３０において後処理装置３５よりもエンジン本体１０側に位置している。 The turbocharger 40 is a supercharger that compresses the intake air flowing through the intake passage 20 by utilizing the flow of exhaust gas flowing through the exhaust passage 30. The turbocharger 40 has a turbine 42T provided in the exhaust passage 30 and a compressor 42C provided in the intake passage 20. The turbine 42T is located on the engine body 10 side of the aftertreatment device 35 in the exhaust passage 30.
　ＥＧＲ装置５０は、排気ガスの一部をエンジン本体１０へ還流させる。具体的には、ＥＧＲ装置５０は、排気通路３０内（ここでは、排気マニホールド３２内）の排気ガスの一部（以下、ＥＧＲガスと呼ぶ）を、吸気通路２０内（ここでは、吸気マニホールド２２内）に還流させる。ＥＧＲ装置５０は、ＥＧＲ通路５２と、ＥＧＲクーラ５３と、ＥＧＲ弁５４と、温度センサ５５とを有する。 The EGR device 50 recirculates a part of the exhaust gas to the engine body 10. Specifically, the EGR device 50 uses a part of the exhaust gas (hereinafter referred to as EGR gas) in the exhaust passage 30 (here, the exhaust manifold 32) in the intake passage 20 (here, the intake manifold 22). (Inside). The EGR device 50 includes an EGR passage 52, an EGR cooler 53, an EGR valve 54, and a temperature sensor 55.
　ＥＧＲ通路５２は、ＥＧＲガスが流れる流路である。ＥＧＲクーラ５３は、ＥＧＲ通路５２に設けられ、ＥＧＲガスを冷却する。ＥＧＲ弁５４は、開閉可能な弁であり、ＥＧＲガスの流量を調整する。温度センサ５５は、ＥＧＲ通路５２を流れるＥＧＲガスの温度を検出する。 The EGR passage 52 is a flow path through which EGR gas flows. The EGR cooler 53 is provided in the EGR passage 52 and cools the EGR gas. The EGR valve 54 is a valve that can be opened and closed, and regulates the flow rate of EGR gas. The temperature sensor 55 detects the temperature of the EGR gas flowing through the EGR passage 52.
　制御装置１００は、内燃機関１全体の動作を制御する。制御装置１００は、内燃機関１の制御モードとして、上述した昇温制御モードと、昇温制御モード以外の通常制御モーとを実行する。また、制御装置１００は、排気ガス中のＮＯｘの排出量を抑制すべく、内燃機関１の吸気の吸気量とＮＯｘ排出量に基づいて、ＥＧＲ弁５４の開度を調整する制御（ＥＧＲ制御とも呼ぶ）を行っている。そして、制御装置１００は、詳細は後述するが、制御モードに応じた吸気量及びＮＯｘ排出量を推定し、推定した吸気及びＮＯｘ排出量に基づいてＥＧＲ制御を行っている。これにより、吸排気の特性が異なる昇温制御モードと通常制御モード時にＥＧＲ制御を高精度に行うことができる。 The control device 100 controls the operation of the entire internal combustion engine 1. The control device 100 executes the above-mentioned temperature rise control mode and the normal control mode other than the temperature rise control mode as the control mode of the internal combustion engine 1. Further, the control device 100 controls to adjust the opening degree of the EGR valve 54 based on the intake amount and the NOx emission amount of the intake air of the internal combustion engine 1 in order to suppress the emission amount of NOx in the exhaust gas (also referred to as EGR control). Call). Then, although the details will be described later, the control device 100 estimates the intake air amount and the NOx emission amount according to the control mode, and performs EGR control based on the estimated intake air amount and the NOx emission amount. As a result, EGR control can be performed with high accuracy in the temperature rise control mode and the normal control mode in which the intake and exhaust characteristics are different.
　＜制御装置の詳細構成＞
　制御装置１００の詳細構成について、図２を参照しながら説明する。 <Detailed configuration of control device>
The detailed configuration of the control device 100 will be described with reference to FIG.
　図２は、制御装置１００の詳細構成を説明するための模式図である。制御装置１００は、記憶部１１０と、制御部１２０とを有する。 FIG. 2 is a schematic diagram for explaining the detailed configuration of the control device 100. The control device 100 has a storage unit 110 and a control unit 120.
　記憶部１１０は、例えばＲＯＭ（Read Only Memory）及びＲＡＭ（Random Access Memory）を含む。記憶部１１０は、制御部１２０が実行するためのプログラムや各種データを記憶する。 The storage unit 110 includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 110 stores programs and various data for execution by the control unit 120.
　制御部１２０は、例えばＣＰＵ（Central Processing Unit）である。制御部１２０は、記憶部１１０に記憶されたプログラムを実行することにより、内燃機関１の動作を制御する。本実施形態では、制御部１２０は、モード判定部１２２、吸気量推定部１２３、ＮＯｘ推定部１２４及びＥＧＲ制御部１２５として機能する。 The control unit 120 is, for example, a CPU (Central Processing Unit). The control unit 120 controls the operation of the internal combustion engine 1 by executing the program stored in the storage unit 110. In the present embodiment, the control unit 120 functions as a mode determination unit 122, an intake air amount estimation unit 123, a NOx estimation unit 124, and an EGR control unit 125.
　モード判定部１２２は、内燃機関１の制御モードを判定する。例えば、モード判定部１２２は、制御モードが昇温制御モード又は通常制御モードであるかを判定する。昇温制御モードは、内燃機関１の冷間始動後から暖機完了までの間、後処理装置３５を早期に昇温させるための制御モードである。通常制御モードは、昇温制御モード以外の制御モードである。モード判定部１２２は、判定結果を吸気量推定部１２３及びＮＯｘ推定部１２４に出力する。 The mode determination unit 122 determines the control mode of the internal combustion engine 1. For example, the mode determination unit 122 determines whether the control mode is the temperature rise control mode or the normal control mode. The temperature rise control mode is a control mode for raising the temperature of the aftertreatment device 35 at an early stage from the cold start of the internal combustion engine 1 to the completion of warming up. The normal control mode is a control mode other than the temperature rise control mode. The mode determination unit 122 outputs the determination result to the intake air amount estimation unit 123 and the NOx estimation unit 124.
　モード判定部１２２は、検出センサ群７０が検出した内燃機関１の状態に基づいて、制御モードを判定する。モード判定部１２２は、内燃機関１を冷却する冷却水の温度と、排気ガスの温度とに基づいて、制御モードを判定してもよい。例えば、モード判定部１２２は、冷却水の温度及び排気ガスの温度がそれぞれ所定値よりも高い場合には、昇温制御モードであると判定し、冷却水の温度及び排気ガスの温度がそれぞれ所定値よりも低い場合には、通常制御モードであると判定する。なお、モード判定部１２２は、冷却水の温度及び排気ガスの温度に加えて、別のパラメータ（例えば、大気圧）を含めて判定してもよい。 The mode determination unit 122 determines the control mode based on the state of the internal combustion engine 1 detected by the detection sensor group 70. The mode determination unit 122 may determine the control mode based on the temperature of the cooling water for cooling the internal combustion engine 1 and the temperature of the exhaust gas. For example, when the temperature of the cooling water and the temperature of the exhaust gas are higher than the predetermined values, the mode determination unit 122 determines that the temperature rise control mode is used, and the temperature of the cooling water and the temperature of the exhaust gas are predetermined respectively. If it is lower than the value, it is determined that the control mode is normal. The mode determination unit 122 may determine by including another parameter (for example, atmospheric pressure) in addition to the temperature of the cooling water and the temperature of the exhaust gas.
　吸気量推定部１２３は、内燃機関１の吸気量を推定する。吸気量推定部１２３は、モード判定部１２２が判定した制御モードに応じて、吸気量を推定する。吸気量推定部１２３は、モード判定部１２２によって通常制御モードであると判定された場合には、通常制御モード時の吸気量である通常時吸気量を推定する。一方で、吸気量推定部１２３は、昇温制御モードであると判定された場合には、昇温制御モード時の吸気量である昇温時吸気量を推定する。なお、通常時吸気量が第１吸気量に該当し、昇温時吸気量が第２吸気量に該当する。 The intake air amount estimation unit 123 estimates the intake air amount of the internal combustion engine 1. The intake air amount estimation unit 123 estimates the intake air amount according to the control mode determined by the mode determination unit 122. When the mode determination unit 122 determines that the mode is in the normal control mode, the intake amount estimation unit 123 estimates the normal intake amount, which is the intake amount in the normal control mode. On the other hand, when it is determined that the intake air amount estimation unit 123 is in the temperature rise control mode, the intake air amount estimation unit 123 estimates the intake air amount at the time of temperature rise, which is the intake amount in the temperature rise control mode. The normal intake amount corresponds to the first intake amount, and the temperature rise intake amount corresponds to the second intake amount.
　ここで、吸気量は、吸気パラメータである推定体積効率と推定吸入空気量の積で求まる。推定体積効率及び推定吸入空気量は、公知の算出方法で求めることができる。例えば、推定体積効率は、エンジン本体１０の回転数と燃料噴射量を用いて求まる。推定吸入空気量は、吸気マニホールド２２の圧力、温度、シリンダ１２内の体積を用いて求まる。本実施形態では、通常時吸気量を求める際の推定体積効率の値（以下、第１値）と、昇温時吸気量を求める際の推定体積効率の値（以下、第２値）とが異なる。具体的には、昇温時は通常時に比べて新気吸入を減らすため、昇温時吸気量を求める際の推定体積効率の第２値は、通常時吸気量を求める際の推定体積効率の第１値よりも小さい。このため、吸気量推定部１２３が推定した昇温時吸気量は、通常時吸気量よりも少ない。 Here, the intake air amount is obtained by the product of the estimated volumetric efficiency, which is an intake air parameter, and the estimated intake air amount. The estimated volumetric efficiency and the estimated intake air amount can be obtained by a known calculation method. For example, the estimated volumetric efficiency can be obtained by using the rotation speed of the engine body 10 and the fuel injection amount. The estimated intake air amount can be obtained by using the pressure, temperature, and volume in the cylinder 12 of the intake manifold 22. In the present embodiment, the value of the estimated volumetric efficiency when calculating the normal intake air amount (hereinafter, the first value) and the value of the estimated volumetric efficiency when calculating the heat intake amount at the time of temperature rise (hereinafter, the second value) are set. different. Specifically, in order to reduce the inhalation of fresh air at the time of temperature rise as compared with the normal time, the second value of the estimated volumetric efficiency at the time of obtaining the intake amount at the time of temperature rise is the estimated volumetric efficiency at the time of obtaining the normal time intake amount. It is smaller than the first value. Therefore, the intake air amount at the time of temperature rise estimated by the intake air amount estimation unit 123 is smaller than the normal intake air amount.
　ＮＯｘ推定部１２４は、ＮＯｘの排出量を推定する。ＮＯｘ推定部１２４は、モード判定部１２２が判定した制御モードに応じて、排出量を推定する。ＮＯｘ推定部１２４は、モード判定部１２２によって通常制御モードであると判定された場合には、通常制御モード時の排出量である通常時排出量を推定する。一方で、ＮＯｘ推定部１２４は、昇温制御モードであると判定された場合には、昇温制御モード時の排出量である昇温時排出量を推定する。なお、通常時排出量が第１排出量に該当し、昇温時排出量が第２排出量に該当する。 The NOx estimation unit 124 estimates the amount of NOx emissions. The NOx estimation unit 124 estimates the emission amount according to the control mode determined by the mode determination unit 122. When the mode determination unit 122 determines that the mode is in the normal control mode, the NOx estimation unit 124 estimates the normal emission amount, which is the emission amount in the normal control mode. On the other hand, when it is determined that the NOx estimation unit 124 is in the temperature rise control mode, the NOx estimation unit 124 estimates the discharge amount at the time of temperature rise, which is the discharge amount in the temperature rise control mode. The normal emission amount corresponds to the first emission amount, and the temperature rising emission amount corresponds to the second emission amount.
　ここで、ＮＯｘの排出量は、エンジン本体１０の回転数と燃料噴射量と環境条件係数との積で求まる。環境条件係数は、エンジン本体１０内の燃焼状態を示すものであり、排出パラメータに該当する。環境条件係数は、例えば、燃料噴射タイミング、冷却水の温度、吸気の温度等を用いて求まる。本実施形態では、通常時排出量を求める際の環境条件係数の値（以下、第１値）と、昇温時排出量を求める際の環境条件係数の値（以下、第２値）とが異なる。具体的には、昇温時は通常時に比べてエンジン本体１０内で完全燃料しないため、昇温時排出量を求める際の環境条件係数の第２値は、通常時排出量を求める際の環境条件係数の第１値よりも小さい。このため、ＮＯｘ推定部１２４が推定した昇温時排出量は、通常時排出量よりも少ない。 Here, the NOx emission amount is obtained by the product of the rotation speed of the engine body 10, the fuel injection amount, and the environmental condition coefficient. The environmental condition coefficient indicates the combustion state in the engine body 10, and corresponds to the emission parameter. The environmental condition coefficient can be obtained by using, for example, the fuel injection timing, the temperature of the cooling water, the temperature of the intake air, and the like. In the present embodiment, the value of the environmental condition coefficient (hereinafter, the first value) when calculating the emission amount at the normal time and the value of the environmental condition coefficient (hereinafter, the second value) at the time of calculating the emission amount at the time of temperature rise are used. different. Specifically, since the engine body 10 does not completely fuel when the temperature rises, the second value of the environmental condition coefficient when calculating the emission amount at the time of temperature rise is the environment when the emission amount at the normal time is calculated. It is smaller than the first value of the condition coefficient. Therefore, the emission amount at the time of temperature rise estimated by the NOx estimation unit 124 is smaller than the emission amount at the normal time.
　ＥＧＲ制御部１２５は、ＥＧＲ装置５０の動作を制御する。例えば、ＥＧＲ制御部１２５は、ＥＧＲ装置５０のＥＧＲ弁５４の開閉制御（ＥＧＲ制御）を行う。ＥＧＲ制御部１２５は、吸気量推定部１２３及びＮＯｘ推定部１２４の推定値に基づいて、ＥＧＲ装置５０の動作を制御する。 The EGR control unit 125 controls the operation of the EGR device 50. For example, the EGR control unit 125 controls the opening / closing (EGR control) of the EGR valve 54 of the EGR device 50. The EGR control unit 125 controls the operation of the EGR device 50 based on the estimated values of the intake air amount estimation unit 123 and the NOx estimation unit 124.
　本実施形態では、ＥＧＲ制御部１２５は、モード判定部１２２が判定した制御モードに応じて吸気量推定部１２３及びＮＯｘ推定部１２４が推定した吸気量及びＮＯｘ排出量に基づいて、ＥＧＲ装置５０を制御する。すなわち、通常制御モードである場合には、ＥＧＲ制御部１２５は、吸気量推定部１２３が推定した通常時吸気量と、ＮＯｘ推定部１２４が推定した通常時排出量とを用いて、ＥＧＲ弁５４の開閉を制御する。一方で、昇温制御モードである場合には、ＥＧＲ制御部１２５は、吸気量推定部１２３が推定した昇温時吸気量と、ＮＯｘ推定部１２４が推定した昇温時排出量とを用いて、ＥＧＲ弁５４の開閉を制御する。 In the present embodiment, the EGR control unit 125 uses the EGR device 50 based on the intake air amount and the NOx emission amount estimated by the intake air amount estimation unit 123 and the NOx estimation unit 124 according to the control mode determined by the mode determination unit 122. Control. That is, in the normal control mode, the EGR control unit 125 uses the normal intake amount estimated by the intake amount estimation unit 123 and the normal discharge amount estimated by the NOx estimation unit 124, and the EGR valve 54 Controls the opening and closing of. On the other hand, in the case of the temperature rise control mode, the EGR control unit 125 uses the intake air amount at temperature temperature estimated by the intake air amount estimation unit 123 and the discharge amount at temperature temperature estimated by the NOx estimation unit 124. , Controls the opening and closing of the EGR valve 54.
　＜内燃機関の動作例＞
　内燃機関１の動作例について、図３を参照しながら説明する。 <Operation example of internal combustion engine>
An operation example of the internal combustion engine 1 will be described with reference to FIG.
　図３は、内燃機関１の動作例を説明するためのフローチャートである。本フローチャートは、内燃機関１が動作を行っているところから開始される。これに伴い、エンジン本体１０から発生した排気ガスが、排気通路３０を流れている。 FIG. 3 is a flowchart for explaining an operation example of the internal combustion engine 1. This flowchart starts from the place where the internal combustion engine 1 is operating. Along with this, the exhaust gas generated from the engine body 10 is flowing through the exhaust passage 30.
　まず、モード判定部１２２は、内燃機関１の制御モードを判定する（ステップＳ１０２）。具体的には、モード判定部１２２は、制御モードが昇温制御モードと通常制御モードのいずれかを判定する。 First, the mode determination unit 122 determines the control mode of the internal combustion engine 1 (step S102). Specifically, the mode determination unit 122 determines whether the control mode is the temperature rise control mode or the normal control mode.
　モード判定部１２２が昇温制御モードであると判定した場合には（ステップＳ１０４：Ｙｅｓ）、吸気量推定部１２３は、昇温制御モード時の吸気量である昇温時吸気量を推定する（ステップＳ１０６）。また、ＮＯｘ推定部１２４は、昇温制御モード時のＮＯｘの排出量である昇温時排出量を推定する（ステップＳ１０８）。なお、ステップＳ１０６の処理とステップＳ１０８の処理は、逆の順番で行われてもよいし、同時に行われてもよい。 When the mode determination unit 122 determines that the temperature rise control mode is set (step S104: Yes), the intake air amount estimation unit 123 estimates the intake air amount at the time of temperature rise, which is the intake air amount in the temperature rise control mode (step S104: Yes). Step S106). Further, the NOx estimation unit 124 estimates the amount of NOx discharged at the time of temperature rise, which is the amount of NOx discharged in the temperature rise control mode (step S108). The processing of step S106 and the processing of step S108 may be performed in the reverse order or may be performed at the same time.
　次に、ＥＧＲ制御部１２５は、吸気量推定部１２３が推定した昇温時吸気量と、ＮＯｘ推定部１２４が推定した昇温時排出量とに基づいて、ＥＧＲ装置５０のＥＧＲ弁５４の開閉を制御する（ステップＳ１１０）。例えば、ＥＧＲ制御部１２５は、ＥＧＲ弁５４の開度を制御する。 Next, the EGR control unit 125 opens and closes the EGR valve 54 of the EGR device 50 based on the intake air amount at the time of temperature rise estimated by the intake air amount estimation unit 123 and the discharge amount at the time of temperature rise estimated by the NOx estimation unit 124. Is controlled (step S110). For example, the EGR control unit 125 controls the opening degree of the EGR valve 54.
　モード判定部１２２が通常制御モードであると判定した場合には（ステップＳ１０４：Ｎｏ）、吸気量推定部１２３は、通常制御モード時の吸気量である通常時吸気量を推定する（ステップＳ１１２）。また、ＮＯｘ推定部１２４は、通常制御モード時のＮＯｘの排出量である通常時排出量を推定する（ステップＳ１１４）。 When the mode determination unit 122 determines that the mode is in the normal control mode (step S104: No), the intake amount estimation unit 123 estimates the normal intake amount, which is the intake amount in the normal control mode (step S112). .. Further, the NOx estimation unit 124 estimates the normal emission amount, which is the NOx emission amount in the normal control mode (step S114).
　次に、ＥＧＲ制御部１２５は、吸気量推定部１２３が推定した通常時吸気量と、ＮＯｘ推定部１２４が推定した通常時排出量とに基づいて、ＥＧＲ弁５４の開閉を制御する（ステップＳ１１６）。例えば、ＥＧＲ制御部１２５は、ＥＧＲ弁５４の開度を制御する。 Next, the EGR control unit 125 controls the opening and closing of the EGR valve 54 based on the normal intake amount estimated by the intake amount estimation unit 123 and the normal discharge amount estimated by the NOx estimation unit 124 (step S116). ). For example, the EGR control unit 125 controls the opening degree of the EGR valve 54.
　＜本実施形態における効果＞
　上述した実施形態の内燃機関１の制御装置１００は、通常制御モード時の吸気量（第１吸気量）及びＮＯｘ排出量（第１排出量）と、昇温制御モード時の吸気量（第１吸気量）及びＮＯｘ排出量（第１排出量）とを、異なる値を用いて推定する。そして、制御装置１００は、制御モードに応じて推定した吸気量及びＮＯｘ排出量に基づいて、ＥＧＲ装置５０の動作を制御する。
　これにより、通常制御モード時の吸気量及びＮＯｘ排出量と、昇温制御モード時の吸気量及びＮＯｘ排出量とを、それぞれ精度良く推定できる。このため、吸気量及びＮＯｘ排出量に基づいたＥＧＲ制御を、通常制御モード時と昇温制御モード時で高精度に行うことができる。 <Effect in this embodiment>
The control device 100 of the internal combustion engine 1 of the above-described embodiment has an intake amount (first intake amount) and NOx emission amount (first emission amount) in the normal control mode and an intake amount (first) in the temperature rise control mode. The intake amount) and the NOx emission amount (first emission amount) are estimated using different values. Then, the control device 100 controls the operation of the EGR device 50 based on the intake amount and the NOx discharge amount estimated according to the control mode.
As a result, the intake amount and NOx emission amount in the normal control mode and the intake amount and NOx emission amount in the temperature rise control mode can be estimated with high accuracy. Therefore, EGR control based on the intake amount and the NOx emission amount can be performed with high accuracy in the normal control mode and the temperature rise control mode.
　以上、本発明を実施の形態を用いて説明したが、本発明の技術的範囲は上記実施の形態に記載の範囲には限定されず、その要旨の範囲内で種々の変形及び変更が可能である。例えば、装置の全部又は一部は、任意の単位で機能的又は物理的に分散・統合して構成することができる。また、複数の実施の形態の任意の組み合わせによって生じる新たな実施の形態も、本発明の実施の形態に含まれる。組み合わせによって生じる新たな実施の形態の効果は、もとの実施の形態の効果を併せ持つ。 Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes can be made within the scope of the gist. be. For example, all or part of the device can be functionally or physically distributed / integrated in any unit. Also included in the embodiments of the present invention are new embodiments resulting from any combination of the plurality of embodiments. The effect of the new embodiment produced by the combination has the effect of the original embodiment together.
　１　　内燃機関
　１０　　エンジン本体
　３５　　後処理装置
　５０　　ＥＧＲ装置
　１００　　制御装置
　１２２　　モード判定部
　１２３　　吸気量推定部
　１２４　　ＮＯｘ推定部
　１２５　　ＥＧＲ制御部 1 Internal combustion engine 10 Engine body 35 Post-processing device 50 EGR device 100 Control device 122 Mode determination unit 123 Intake amount estimation unit 124 NOx estimation unit 125 EGR control unit

Claims (7)

  1. 　内燃機関の制御モードが、前記内燃機関の排気ガスを浄化する後処理装置を昇温させる昇温制御モードか、前記昇温制御モード以外の通常制御モードかを判定するモード判定部と、
    　前記通常制御モードと判定された場合には、吸気パラメータの第１値を用いて前記内燃機関の吸気量である第１吸気量を推定し、前記昇温制御モードと判定された場合には、前記吸気パラメータの前記第１値とは異なる第２値を用いて第２吸気量を推定する吸気量推定部と、
    　前記通常制御モードと判定された場合には、排出パラメータの第１値を用いて前記排気ガス中のＮＯｘ排出量である第１排出量を推定し、前記昇温制御モードと判定された場合には、前記排出パラメータの第１値とは異なる第２値を用いて第２排出量を推定するＮＯｘ推定部と、
    　前記モード判定部が判定した制御モードに応じて前記吸気量推定部及びＮＯｘ推定部が推定した吸気量及びＮＯｘ排出量に基づいて、前記排気ガスの一部を還流させるＥＧＲ装置を制御するＥＧＲ制御部と、
    　を備える、内燃機関の制御装置。     A mode determination unit for determining whether the control mode of the internal combustion engine is a temperature rise control mode for raising the temperature of the aftertreatment device for purifying the exhaust gas of the internal combustion engine or a normal control mode other than the temperature rise control mode.
    When the normal control mode is determined, the first intake amount, which is the intake amount of the internal combustion engine, is estimated using the first value of the intake parameter, and when the temperature rise control mode is determined, the temperature rise control mode is determined. An intake amount estimation unit that estimates a second intake amount using a second value different from the first value of the intake parameter,
    When the normal control mode is determined, the first emission amount, which is the NOx emission amount in the exhaust gas, is estimated using the first value of the emission parameter, and when the temperature rise control mode is determined. Is a NOx estimation unit that estimates the second emission amount using a second value different from the first value of the emission parameter.
    EGR control that controls an EGR device that recirculates a part of the exhaust gas based on the intake amount and NOx emission amount estimated by the intake amount estimation unit and the NOx estimation unit according to the control mode determined by the mode determination unit. Department and
    A control device for an internal combustion engine.
  2. 　前記吸気量推定部は、内燃機関本体の推定体積効率の第１値を用いて前記第１吸気量を推定し、前記推定体積効率の第１値より小さい第２値を用いて前記第２吸気量を推定する、
    　請求項１に記載の内燃機関の制御装置。     The intake amount estimation unit estimates the first intake amount using the first value of the estimated volumetric efficiency of the internal combustion engine main body, and the second intake using a second value smaller than the first value of the estimated volume efficiency. Estimate the amount,
    The control device for an internal combustion engine according to claim 1.
  3. 　前記吸気量推定部は、前記内燃機関本体の回転数及び燃料噴射量を用いて求まる前記推定体積効率の前記第１値を用いて前記第１吸気量を推定し、前記推定体積効率の前記第２値を用いて前記第２吸気量を推定する、
    　請求項２に記載の内燃機関の制御装置。     The intake amount estimation unit estimates the first intake amount using the first value of the estimated volumetric efficiency obtained by using the rotation speed and the fuel injection amount of the internal combustion engine main body, and the first of the estimated volumetric efficiency. The second inspiratory quantity is estimated using two values.
    The control device for an internal combustion engine according to claim 2.
  4. 　前記ＮＯｘ推定部は、内燃機関本体の燃焼状態を示す環境条件係数の第１値を用いて前記第１排出量を推定し、前記環境条件係数の第１値より小さい第２値を用いて前記第２排出量を推定する、
    　請求項１から３のいずれか１項に記載の内燃機関の制御装置。     The NOx estimation unit estimates the first emission amount using the first value of the environmental condition coefficient indicating the combustion state of the internal combustion engine main body, and uses the second value smaller than the first value of the environmental condition coefficient. Estimate the second emission,
    The control device for an internal combustion engine according to any one of claims 1 to 3.
  5. 　前記ＮＯｘ推定部は、燃料噴射タイミング、冷却水の温度及び吸気の温度を用いて求まる前記環境条件係数の第１値を用いて前記第１排出量を推定し、前記環境条件係数の前記第２値を用いて前記第２排出量を推定する、
    　請求項４に記載の内燃機関の制御装置。     The NOx estimation unit estimates the first emission amount using the first value of the environmental condition coefficient obtained by using the fuel injection timing, the temperature of the cooling water, and the temperature of the intake air, and the second of the environmental condition coefficients. Estimate the second emission using the value,
    The control device for an internal combustion engine according to claim 4.
  6. 　前記モード判定部は、前記内燃機関を冷却する冷却水の温度と、前記排気ガスの温度とに基づいて、前記昇温制御モードか否かを判定する、
    　請求項１から５のいずれか１項に記載の内燃機関の制御装置。     The mode determination unit determines whether or not the temperature rise control mode is based on the temperature of the cooling water for cooling the internal combustion engine and the temperature of the exhaust gas.
    The control device for an internal combustion engine according to any one of claims 1 to 5.
  7. 　前記モード判定部は、
    　前記冷却水の温度及び前記排気ガスの温度が所定値よりも高い場合には、前記昇温制御モードであると判定し、
    　前記冷却水の温度及び前記排気ガスの温度が前記所定値よりも低い場合には、前記通常制御モードであると判定する、
    　請求項６に記載の内燃機関の制御装置。     The mode determination unit
    When the temperature of the cooling water and the temperature of the exhaust gas are higher than the predetermined values, it is determined that the temperature rise control mode is used.
    When the temperature of the cooling water and the temperature of the exhaust gas are lower than the predetermined values, it is determined that the normal control mode is used.
    The control device for an internal combustion engine according to claim 6.
PCT/JP2021/025265 2020-07-16 2021-07-05 Control device for internal combustion engine WO2022014388A1 (en)

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JP2001073789A (en) * 1999-09-07 2001-03-21 Mitsubishi Motors Corp Supercharging pressure control system for internal combustion engine
JP2001091370A (en) * 1999-09-27 2001-04-06 Mitsubishi Motors Corp Fluid temperature estimating device
JP2002180871A (en) * 2000-12-07 2002-06-26 Denso Corp Catalyst early warming-up controller for internal combustion engine
JP2002180885A (en) * 2000-12-14 2002-06-26 Toyota Motor Corp Exhaust emission control device for internal combustion engine
JP2003138974A (en) * 2001-10-30 2003-05-14 Kokusan Denki Co Ltd Method of predicting pressure inside intake pipe of internal combustion engine and method of controlling fuel injection
JP2008121459A (en) * 2006-11-09 2008-05-29 Toyota Motor Corp Method for correcting measurement value of intake air flow rate measuring device

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JPS57168040A (en) * 1981-04-10 1982-10-16 Nippon Kokan Kk <Nkk> Method to determine combustion condition of diesel engine
JP2001073789A (en) * 1999-09-07 2001-03-21 Mitsubishi Motors Corp Supercharging pressure control system for internal combustion engine
JP2001091370A (en) * 1999-09-27 2001-04-06 Mitsubishi Motors Corp Fluid temperature estimating device
JP2002180871A (en) * 2000-12-07 2002-06-26 Denso Corp Catalyst early warming-up controller for internal combustion engine
JP2002180885A (en) * 2000-12-14 2002-06-26 Toyota Motor Corp Exhaust emission control device for internal combustion engine
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