WO2023238361A1 - 内燃機関の制御方法および制御装置 - Google Patents

内燃機関の制御方法および制御装置 Download PDF

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Publication number
WO2023238361A1
WO2023238361A1 PCT/JP2022/023392 JP2022023392W WO2023238361A1 WO 2023238361 A1 WO2023238361 A1 WO 2023238361A1 JP 2022023392 W JP2022023392 W JP 2022023392W WO 2023238361 A1 WO2023238361 A1 WO 2023238361A1
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Prior art keywords
oxygen storage
storage capacity
way catalyst
internal combustion
combustion engine
Prior art date
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Ceased
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PCT/JP2022/023392
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English (en)
French (fr)
Japanese (ja)
Inventor
民一 木村
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Nissan Motor Co Ltd
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Nissan Motor Co Ltd
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Publication date
Application filed by Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Priority to CN202280096182.XA priority Critical patent/CN119213203A/zh
Priority to JP2024526183A priority patent/JP7740546B2/ja
Priority to PCT/JP2022/023392 priority patent/WO2023238361A1/ja
Priority to EP22945139.8A priority patent/EP4538508A1/en
Priority to US18/873,019 priority patent/US12529330B2/en
Publication of WO2023238361A1 publication Critical patent/WO2023238361A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • 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
    • F01N11/007—Monitoring or diagnostic devices for exhaust-gas treatment apparatus the diagnostic devices measuring oxygen or air concentration downstream of the exhaust 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
    • 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
    • F01N3/101—Three-way catalysts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N2550/00—Monitoring or diagnosing the deterioration of exhaust systems
    • F01N2550/02—Catalytic activity of catalytic converters
    • 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
    • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/02—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor
    • F01N2560/025—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor for measuring or detecting O2, e.g. lambda sensors
    • 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
    • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/14—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics having more than one sensor of one kind
    • 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
    • F01N2900/04—Methods of control or diagnosing
    • F01N2900/0412—Methods of control or diagnosing using pre-calibrated maps, tables or charts
    • 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
    • F01N2900/08—Parameters used for exhaust control or diagnosing said parameters being related to the engine
    • 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
    • F01N2900/14—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust gas
    • F01N2900/1411—Exhaust gas flow rate, e.g. mass flow rate or volumetric flow rate
    • 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
    • F01N2900/1624—Catalyst oxygen storage capacity
    • 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
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention relates to a control method and device for diagnosing deterioration of a three-way catalyst provided in an exhaust passage of an internal combustion engine based on the oxygen storage capacity of the three-way catalyst.
  • a three-way catalyst is capable of oxidizing CO and HC and reducing NOx in exhaust gas, but in order to achieve both oxidation and reduction at a high level through catalytic action, the catalyst must absorb and release oxygen.
  • the so-called oxygen storage capacity is important.
  • the maximum oxygen storage capacity of the three-way catalyst installed in the exhaust passage of an internal combustion engine decreases as the catalyst deteriorates (permanently and temporarily). . Therefore, various techniques have been proposed to determine the oxygen storage capacity of the three-way catalyst in some way during operation of the internal combustion engine, and to diagnose catalyst deterioration based on how much the actual oxygen storage capacity has decreased from the initial oxygen storage capacity. (For example, Patent Document 1).
  • the initial oxygen storage capacity to be compared is a value set corresponding to the initial state of the three-way catalyst, that is, the characteristics of a new three-way catalyst, as suggested in Patent Document 1.
  • the substantial oxygen storage capacity of the three-way catalyst during operation is affected by the gas flow rate flowing into the three-way catalyst.
  • the gas flow rate through the three-way catalyst is large, the flow rate of gas passing through the catalyst layer of the three-way catalyst is high, and the oxygen storage amount is relatively small compared to when the gas flow rate is low. Oxygen and NOx escape.
  • Patent Document 1 Conventional techniques such as those disclosed in Patent Document 1 do not take into account such substantial changes in oxygen storage capacity related to gas flow rate, and for example, when deterioration diagnosis is performed under operating conditions where gas flow rate is large. erroneous judgments are likely to occur.
  • the present invention provides a control method for an internal combustion engine that includes a three-way catalyst in an exhaust passage and diagnoses catalyst deterioration based on a decrease in oxygen storage capacity of the three-way catalyst from a reference oxygen storage capacity.
  • the reference oxygen storage capacity is set in accordance with the gas flow rate flowing into the three-way catalyst such that the larger the gas flow rate, the smaller the reference oxygen storage capacity.
  • FIG. 1 is an explanatory diagram of a configuration of an internal combustion engine according to an embodiment including a three-way catalyst.
  • FIG. 2 is a characteristic diagram showing an example of operating points of an internal combustion engine according to an embodiment.
  • FIG. 3 is a functional block diagram of control according to an embodiment.
  • FIG. 3 is a characteristic diagram showing characteristics of reference oxygen storage capacity with respect to intake air amount.
  • FIG. 1 is an explanatory diagram showing a schematic configuration of an internal combustion engine 1 according to an embodiment to which the present invention is applied.
  • the internal combustion engine 1 of one embodiment is used in a series hybrid vehicle as a power generation internal combustion engine that drives a power generation motor generator, which mainly operates as a generator, in accordance with electric power demand, and is a four-stroke cycle spark ignition engine. It consists of a type internal combustion engine (so-called gasoline engine).
  • gasoline engine a type internal combustion engine
  • One example is an in-line three-cylinder engine, and each cylinder is provided with an intake valve 2, an exhaust valve 3, and a spark plug 4.
  • the illustrated example is configured as a cylinder direct injection type engine, and a fuel injection valve 5 that injects fuel into the cylinder is arranged, for example, on the intake valve 2 side.
  • a port injection type configuration in which fuel is injected toward the intake port 6 may be used.
  • An electronically controlled throttle valve 10 whose opening degree is controlled by a control signal from an engine controller 9 is installed on the upstream side of the collector portion 8 of the intake passage 7 connected to the intake port 6 of each cylinder.
  • An air flow meter 11 for detecting the amount of intake air is disposed upstream of the throttle valve 10, and an air cleaner 12 is disposed further upstream.
  • the exhaust ports 13 of each cylinder are combined into one exhaust passage 14, and this exhaust passage 14 is provided with a three-way catalyst 15 for purifying exhaust gas.
  • the three-way catalyst 15 is, for example, a so-called monolithic ceramic catalyst in which a catalyst layer containing a catalyst metal is coated on the surface of a monolithic ceramic body in which fine passages are formed.
  • the three-way catalyst 15 may include a plurality of catalysts (for example, a manifold catalyst and an underfloor catalyst) arranged in series.
  • An upstream air-fuel ratio sensor 19 for detecting the exhaust air-fuel ratio is arranged on the inlet side of the three-way catalyst 15 in the exhaust passage 14, that is, at a position upstream of the three-way catalyst 15.
  • This upstream air-fuel ratio sensor 19 is a so-called wide-range air-fuel ratio sensor that can obtain an output according to the exhaust air-fuel ratio.
  • a response is provided to the composition of the exhaust gas that has passed through the three-way catalyst 15 in order to calibrate the air-fuel ratio feedback control system including the upstream air-fuel ratio sensor 19, diagnose deterioration of the three-way catalyst 15, etc.
  • a downstream air-fuel ratio sensor 20 is arranged.
  • the downstream air-fuel ratio sensor 20 may be, for example, an O2 sensor, but in one example, a so-called wide-range air-fuel ratio sensor is used like the upstream air-fuel ratio sensor 19.
  • Detection signals from the air-fuel ratio sensors 19 and 20 and the air flow meter 11 are input to the engine controller 9.
  • the engine controller 9 is further input with detection signals from a large number of sensors, such as a crank angle sensor 21 for detecting engine rotational speed and a water temperature sensor 22 for detecting cooling water temperature. Based on these input signals, the engine controller 9 optimally controls the fuel injection amount and injection timing by the fuel injection valve 5, the ignition timing by the spark plug 4, the opening degree of the throttle valve 10, etc.
  • the engine controller 9 is connected via an in-vehicle network 32 such as CAN communication to an integrated controller 31 that controls the entire series hybrid vehicle including a driving motor generator, etc., and various functions including starting and stopping are controlled from the integrated controller 31. receive a request or command.
  • the internal combustion engine 1 of one embodiment is an internal combustion engine for power generation in a series hybrid vehicle, it is basically started when the SOC of the vehicle running battery decreases, and as illustrated in FIG.
  • the motor is operated at several predetermined operating points (combinations of load and rotational speed) depending on the magnitude of the rotational speed.
  • four operating points P1 to P4 are shown in FIG. 2, when the power generation demand is relatively small, the operation is performed at the operating point P1, which is set near the best fuel efficiency point, and the larger the power generation demand, the more Operating points P2, P3, and P4 that are on the high-speed, high-load side are selected. Note that these operating points are not exactly one point, but each includes an appropriate range of rotational speed and load, although it is a relatively narrow range.
  • the engine controller 9 performs air-fuel ratio control to optimize the exhaust purification performance of the three-way catalyst 15.
  • the oxygen storage amount of the three-way catalyst 15 is estimated based on the exhaust air-fuel ratio detected by the upstream air-fuel ratio sensor 19, and this oxygen storage amount is determined as the target oxygen storage amount (as described later, the reference oxygen storage capacity).
  • the fuel injection amount (injection pulse width) of the fuel injection valve 5 is feedback-controlled so that the fuel injection amount (injection pulse width) is set to an intermediate value.
  • the engine controller 9 diagnoses the deterioration of the three-way catalyst 15 while the internal combustion engine 1 is operating.
  • the maximum oxygen storage capacity of the three-way catalyst 15, that is, the oxygen storage capacity decreases as the catalyst deteriorates (permanent deterioration and temporary deterioration). Therefore, the current oxygen storage capacity of the three-way catalyst 15 is determined while the internal combustion engine 1 is operating, and this oxygen storage capacity is calculated from the standard oxygen storage capacity (for example, corresponding to the oxygen storage capacity of a new three-way catalyst 15). Catalyst deterioration can be diagnosed by determining the degree of deterioration.
  • the oxygen storage amount is 0; Since the oxygen storage amount can be considered to be saturated when the reverse occurs, the current oxygen storage capacity can be determined from the relationship with the oxygen storage amount estimated based on the exhaust air-fuel ratio detected by the upstream air-fuel ratio sensor 19. I can do it. By comparing this current oxygen storage capacity with a reference oxygen storage capacity, it is determined whether the catalyst has deteriorated. For example, if the current oxygen storage capacity is lower than the reference oxygen storage capacity by a predetermined percentage, it is determined that the oxygen storage capacity has deteriorated.
  • the reference oxygen storage capacity which serves as a reference for determining deterioration, is set in consideration of the gas flow rate flowing into the three-way catalyst 15.
  • the substantial oxygen storage capacity of the three-way catalyst 15 during operation is affected by the gas flow rate entering the three-way catalyst 15.
  • the gas flow rate flowing through the three-way catalyst 15 is large, the flow rate of gas passing through the catalyst layer of the three-way catalyst 15 becomes high, and at a stage where the amount of oxygen storage is relatively small compared to when the gas flow rate is small. Oxygen and NOx flow downstream. Therefore, if the standard oxygen storage capacity is fixedly determined according to the oxygen storage capacity when new without considering the influence of this gas flow rate, the actual oxygen storage capacity will decrease when the gas flow rate is large. Misjudgment may occur.
  • the reference oxygen storage capacity is set according to the gas flow rate so that the larger the gas flow rate, the smaller the reference oxygen storage capacity.
  • the intake air amount detected by the air flow meter 11 is used as a parameter corresponding to the gas flow rate flowing into the three-way catalyst 15. Note that the "intake air amount” does not refer to the amount of air per cylinder cycle, but refers to the flow rate of air taken into the internal combustion engine 1 (that is, passing through the air flow meter 11) per unit time.
  • one of the controls executed by the engine controller 9 includes perturbation control for suppressing or canceling temporary deterioration (also called temporary poisoning) of the catalyst performance of the three-way catalyst 15.
  • Perturbation control periodically repeats rich combustion with a large equivalence ratio and lean combustion with a small equivalence ratio. For example, in an internal combustion engine 1 having multiple cylinders, rich combustion is performed N times according to the combustion order. is performed continuously, then lean combustion is performed continuously N times, and these are repeated periodically.
  • Temporary catalyst deterioration is a phenomenon in which oxygen, HC, etc. adhere to the catalyst metal surface, reducing the catalyst metal surface area and reducing catalyst performance. The poisonous substances covering the catalytic metal surface are peeled off and the catalytic performance is restored. Note that even during such perturbation control, the average air-fuel ratio is maintained near the stoichiometric air-fuel ratio.
  • the internal combustion engine 1 of the embodiment is operated at the four operating points P1 to P4 illustrated in FIG. 2, but temporary deterioration of the catalyst is likely to occur under the operating point P4, which is the highest speed and high load side. .
  • perturbation control is executed in parallel when the internal combustion engine 1 is operated at the operating point P4. This suppresses or eliminates temporary deterioration of the catalyst.
  • perturbation control needs to be performed within a range that ensures the conversion rates of HC, CO, and NOx in the three-way catalyst 15. For example, if the lean combustion period in perturbation control (in other words, the number N of consecutive lean combustions) is excessively long, lean combustion will continue even after the oxygen storage amount of the three-way catalyst 15 is saturated, resulting in NOx Similarly, if the rich combustion period (number of consecutive rich combustions N) is excessively long, rich combustion will continue even after the oxygen storage amount of the three-way catalyst 15 reaches 0. HC etc. flow out downstream of the three-way catalyst 15.
  • the lean combustion period in perturbation control in other words, the number N of consecutive lean combustions
  • the rich combustion period number of consecutive rich combustions N
  • the optimum rich/lean fluctuation cycle in perturbation control is determined according to the oxygen storage capacity of the three-way catalyst 15 so that the conversion rate does not decrease on both the lean side and the rich side.
  • the actual oxygen storage capacity is affected by the magnitude of the gas flow rate flowing into the three-way catalyst 15, so in one embodiment, the oxygen storage capacity is affected by the gas flow rate flowing into the three-way catalyst 15, that is, the amount of intake air.
  • the rich/lean cycle in perturbation control is set based on the above reference oxygen storage capacity. Specifically, when the gas flow rate is large and the reference oxygen storage capacity is small, the period is set relatively short. For example, at operating point P4 in FIG.
  • the gas flow rate (intake air amount) is larger than at other operating points P1 to P3, but the period in perturbation control is relatively large based on the reference oxygen storage capacity at that time. Since the value is set to a relatively short value, temporary deterioration can be alleviated while suppressing a decrease in the conversion rate due to an excessively long rich combustion period or lean combustion period as described above.
  • FIG. 3 is a functional block diagram of control regarding reference oxygen storage capacity in one embodiment. Note that the functions shown in this block diagram are realized by software or hardware executed by the engine controller 9. As shown in the figure, this functional block diagram includes an intake air amount calculation section 101, an oxygen amount calculation section 102, an oxygen storage estimation section 103, a catalyst diagnosis section 104, an air-fuel ratio control section 105, and a cycle setting section. 106 is included.
  • the oxygen storage estimation section 103 includes a reference oxygen storage capacity calculation section 107 , an oxygen storage amount calculation section 108 , a lean side reset section 109 , and a rich side reset section 110 .
  • the intake air amount calculation unit 101 calculates the amount of intake air taken into the internal combustion engine 1 based on the detection signal of the air flow meter 11. This intake air amount is regarded as the gas flow rate flowing into the three-way catalyst 15.
  • the oxygen amount calculation unit 102 calculates the amount of oxygen flowing into the three-way catalyst 15 per unit time based on the exhaust air-fuel ratio detected by the upstream air-fuel ratio sensor 19 and the gas flow rate flowing into the three-way catalyst 15, that is, the amount of intake air. demand. Note that the oxygen amount is given as both positive and negative values. In other words, if the air-fuel ratio is rich, the oxygen amount will be a negative value.
  • the oxygen storage amount calculation unit 108 calculates the current oxygen storage amount by integrating the oxygen amount per unit time output by the oxygen amount calculation unit 102. This current oxygen storage amount value is input to the catalyst diagnosis section 104 and the air-fuel ratio control section 105, respectively.
  • the reference oxygen storage capacity calculation unit 107 calculates the reference oxygen storage capacity according to the intake air amount output by the intake air amount calculation unit 101 (that is, the gas flow rate flowing into the three-way catalyst 15).
  • a characteristic map as shown in FIG. 4 is provided in which values of reference oxygen storage capacity are assigned using the intake air amount as a parameter, and this map is used to determine the reference oxygen storage capacity corresponding to the intake air amount. seek. As shown in FIG. 4, the larger the intake air amount, the smaller the reference oxygen storage capacity.
  • the oxygen storage amount is the amount of oxygen when the three-way catalyst 15 is new and the gas flow rate is the minimum.
  • the storage amount can be expressed as a percentage of 100 (%). Therefore, the reference oxygen storage capacity is 100 (%) when the amount of intake air is minimum, and becomes a smaller percentage as the amount of intake air is larger.
  • the value of the reference oxygen storage capacity determined by the reference oxygen storage capacity calculation unit 107 in this manner is given to the oxygen storage amount calculation unit 108 as an upper limit value.
  • the oxygen storage amount output by the oxygen storage amount calculation unit 108 is limited by this upper limit value. In other words, the oxygen storage amount estimated by the integration in the oxygen storage amount calculation unit 108 does not exceed the reference oxygen storage capacity that takes into account the intake air amount.
  • the value of the reference oxygen storage capacity calculated by the reference oxygen storage capacity calculation unit 107 is input to the catalyst diagnosis unit 104, the air-fuel ratio control unit 105, and the cycle setting unit 106, respectively.
  • the catalyst diagnosis unit 104 determines whether or not the catalyst has deteriorated by comparing the current oxygen storage capacity with the reference oxygen storage capacity.
  • a reference oxygen storage capacity value that takes into account the amount of intake air is used. This suppresses misjudgment when, for example, the gas flow rate flowing into the three-way catalyst 15 is large.
  • the air-fuel ratio control unit 105 sets a target oxygen storage amount in air-fuel ratio control using a reference oxygen storage capacity that takes into account the amount of intake air. For example, a value of 1/2 of the reference oxygen storage capacity is set as the target oxygen storage amount. Thereby, air-fuel ratio control suitable for the actual oxygen storage capacity, which changes depending on the gas flow rate, is realized.
  • the cycle setting unit 106 sets the rich/lean cycle in the perturbation control described above based on the reference oxygen storage capacity corresponding to the intake air amount.
  • the lean-side reset unit 109 and rich-side reset unit 110 included in the oxygen storage estimation unit 103 calculate the integration by the oxygen storage amount calculation unit 108 based on the reversal of the air-fuel ratio detected by the downstream air-fuel ratio sensor 20 to lean/rich. or reset the current estimated oxygen storage amount.
  • the lean-side reset unit 109 considers that the oxygen storage capacity of the three-way catalyst 15 is saturated when the air-fuel ratio detected by the downstream air-fuel ratio sensor 20 becomes lean, and uses the value of the reference oxygen storage capacity. Reset oxygen storage estimate.
  • the reference oxygen storage capacity a reference oxygen storage capacity that takes into account the amount of intake air output by the reference oxygen storage capacity calculation unit 107 is used.
  • the rich-side reset unit 110 assumes that the oxygen storage amount of the three-way catalyst 15 has become 0 when the air-fuel ratio detected by the downstream air-fuel ratio sensor 20 becomes rich, and resets the estimated value of the oxygen storage amount to 0. .
  • the accuracy of the oxygen storage amount estimated by integration is increased.
  • the intake air amount is used as a parameter corresponding to the gas flow rate flowing into the three-way catalyst 15, but the exhaust gas flow rate is calculated based on the intake air amount and taking into account combustion.
  • the flow rate of exhaust gas flowing through the exhaust passage may be detected by some means.
  • the "intake air amount” may be either a mass flow rate or a volumetric flow rate, and for example, the relationship between the target oxygen storage amount and the intake air amount as shown in FIG. You can set it in the form.
  • the present invention is applied to an internal combustion engine for power generation in a series hybrid vehicle, but the present invention can be widely applied not only to an internal combustion engine for power generation, but also to an internal combustion engine that drives a vehicle. be.
  • perturbation control is always executed at a specific operating point, but regardless of the operating point, perturbation control is executed when temporary deterioration of the catalyst is detected or estimated. Good too.
  • the "reference oxygen storage capacity” is treated as the maximum oxygen storage capacity at which the oxygen storage amount becomes saturated under each intake air amount, but in the present invention, the “reference oxygen storage capacity” is The threshold value that is compared with the storage capacity itself may be determined as the “reference oxygen storage capacity" in accordance with the intake air amount or gas flow rate.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
PCT/JP2022/023392 2022-06-10 2022-06-10 内燃機関の制御方法および制御装置 Ceased WO2023238361A1 (ja)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CN202280096182.XA CN119213203A (zh) 2022-06-10 2022-06-10 内燃机的控制方法以及控制装置
JP2024526183A JP7740546B2 (ja) 2022-06-10 2022-06-10 内燃機関の制御方法および制御装置
PCT/JP2022/023392 WO2023238361A1 (ja) 2022-06-10 2022-06-10 内燃機関の制御方法および制御装置
EP22945139.8A EP4538508A1 (en) 2022-06-10 2022-06-10 Control method and control device for internal combustion engine
US18/873,019 US12529330B2 (en) 2022-06-10 2022-06-10 Control method and control device for internal combustion engine

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PCT/JP2022/023392 WO2023238361A1 (ja) 2022-06-10 2022-06-10 内燃機関の制御方法および制御装置

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2023223504A1 (https=) * 2022-05-19 2023-11-23

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06212955A (ja) * 1993-01-22 1994-08-02 Honda Motor Co Ltd 内燃エンジンの触媒劣化検出装置
JP2001329832A (ja) 2000-05-22 2001-11-30 Unisia Jecs Corp 内燃機関の触媒劣化診断装置
WO2012086078A1 (ja) * 2010-12-24 2012-06-28 トヨタ自動車株式会社 内燃機関の制御装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016114901A1 (de) * 2016-08-11 2018-02-15 Volkswagen Aktiengesellschaft Diagnoseverfahren und Vorrichtung zur Überprüfung der Funktionsfähigkeit einer Komponente zur Abgasnachbehandlung

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06212955A (ja) * 1993-01-22 1994-08-02 Honda Motor Co Ltd 内燃エンジンの触媒劣化検出装置
JP2001329832A (ja) 2000-05-22 2001-11-30 Unisia Jecs Corp 内燃機関の触媒劣化診断装置
WO2012086078A1 (ja) * 2010-12-24 2012-06-28 トヨタ自動車株式会社 内燃機関の制御装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2023223504A1 (https=) * 2022-05-19 2023-11-23
JP7718589B2 (ja) 2022-05-19 2025-08-05 日産自動車株式会社 三元触媒の酸素ストレージ量制御方法および装置

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