WO2015137003A1 - 内燃機関の燃焼制御装置 - Google Patents
内燃機関の燃焼制御装置 Download PDFInfo
- Publication number
- WO2015137003A1 WO2015137003A1 PCT/JP2015/052676 JP2015052676W WO2015137003A1 WO 2015137003 A1 WO2015137003 A1 WO 2015137003A1 JP 2015052676 W JP2015052676 W JP 2015052676W WO 2015137003 A1 WO2015137003 A1 WO 2015137003A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- air
- fuel ratio
- fuel
- combustion
- ignition
- Prior art date
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D37/00—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for
- F02D37/02—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for one of the functions being ignition
-
- 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
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/024—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus
- F02D41/0255—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus to accelerate the warming-up of the exhaust gas treating apparatus at engine start
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
- F02D41/1456—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio with sensor output signal being linear or quasi-linear with the concentration of oxygen
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
- F02D41/1461—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration of the exhaust gases emitted by the 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
- F02D41/30—Controlling fuel injection
- F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
- F02D41/3017—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used
- F02D41/3035—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the premixed charge compression-ignition mode
- F02D41/3041—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the premixed charge compression-ignition mode with means for triggering compression ignition, e.g. spark plug
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
- F02D41/402—Multiple injections
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P15/00—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits
- F02P15/10—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits having continuous electric sparks
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P3/00—Other installations
- F02P3/02—Other installations having inductive energy storage, e.g. arrangements of induction coils
- F02P3/04—Layout of circuits
- F02P3/045—Layout of circuits for control of the dwell or anti dwell time
- F02P3/0453—Opening or closing the primary coil circuit with semiconductor devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/045—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions combined with electronic control of other engine functions, e.g. fuel injection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
- F02P5/15—Digital data processing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
- F02P5/15—Digital data processing
- F02P5/1502—Digital data processing using one central computing unit
- F02P5/1506—Digital data processing using one central computing unit with particular means during starting
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/008—Mounting or arrangement of exhaust sensors in or on 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
- 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
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/08—Exhaust gas treatment apparatus parameters
- F02D2200/0802—Temperature of the exhaust gas treatment apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0002—Controlling intake air
-
- 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
-
- 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 combustion control device for an internal combustion engine, and more particularly to a combustion control device for burning a homogeneous and lean air-fuel mixture by spark ignition.
- Patent Document 1 A lean mixture combustion technique for spark-igniting a lean (high air-fuel ratio) mixture is widely known, for example, as shown in Patent Document 1.
- NOx contained in the exhaust gas cannot be purified by a three-way catalyst, so it is important to increase the combustion limit air-fuel ratio.
- Patent Document 1 discloses a technique for stably combusting while increasing the average air-fuel ratio of the air-fuel mixture in the entire combustion chamber by stratifying and arranging a relatively rich air-fuel mixture (small air-fuel ratio) near the spark plug. Has been.
- this technique since the amount of NOx generated by the combustion in the vicinity of the spark plug is large, it is required to further reduce the NOx emission amount.
- Non-Patent Document 1 As a method for reliably burning a homogeneous lean air-fuel mixture having an air-fuel ratio of about “30”, the compression ratio is set so as to raise the air-fuel mixture temperature at ignition to a desired temperature, It has been proposed to use a fuel injection valve.
- Non-Patent Document 1 shows that the proposed spark ignition combustion of a homogeneous lean mixture can surely burn a homogeneous lean mixture having an air-fuel ratio of about “30” to reduce NOx emissions. There is still room for further study on specific combustion control methods to be applied to mass-produced engines.
- the present invention has been made in view of such a situation.
- An object is to provide a control device.
- the present invention provides spark ignition means for performing spark ignition of an air-fuel mixture in a combustion chamber (1) of an internal combustion engine, ignition control means for controlling the spark ignition means, and air-fuel mixture in the combustion chamber.
- An air-fuel ratio control means for controlling the air-fuel ratio of the engine is provided.
- the combustion control device includes a homogeneous lean air-fuel mixture forming means for forming a homogeneous and lean air-fuel mixture in the combustion chamber.
- the spark ignition means generates a discharge in the spark plug (8) and the spark plug.
- a plurality of ignition coil pairs (71, 72), and the discharge start timing (CAIG) and duration (TSPK) of the spark plug can be changed.
- the fuel is injected into the intake passage (2) of the engine using a fuel injection valve (6) that can be atomized and injected, and the air-fuel ratio control means sets the air-fuel ratio to a leaner side than the stoichiometric air-fuel ratio.
- the lean air-fuel ratio is controlled to be leaner than a predetermined lean air-fuel ratio (AFL1), and the ignition control means controls the discharge start timing (CAIG) and the discharge duration (TSPK) in the spark plug,
- the electric start timing (CAIG) set to the advance side than the discharge start timing when the air-fuel ratio of the mixture in the spark plug vicinity igniting the stratified lean air-fuel mixture is formed to be relatively small.
- the air-fuel ratio is controlled to be a lean air-fuel ratio that is further leaner than the predetermined lean air-fuel ratio, and the atomized fuel is injected into the intake passage.
- a lean air-fuel mixture is formed in the intake passage and further sucked into the combustion chamber, whereby a lean air-fuel mixture with higher homogeneity can be formed.
- the discharge start timing and discharge duration in the spark plug can be changed, by appropriately setting the discharge start timing and discharge duration, that is, the lead angle from the discharge start timing when igniting a stratified lean mixture is set. By setting the discharge start time on the side, it is possible to set a long discharge duration, and to reliably ignite a homogeneous lean air-fuel mixture.
- the ignition control means advances the discharge start timing (CAIG) and increases the discharge duration (TSPK) as the air-fuel ratio increases in the air-fuel ratio range leaner than the predetermined lean air-fuel ratio (AFL1). ) Should be set longer.
- CAIG discharge start timing
- TSPK discharge duration
- control is performed to advance the discharge start timing and set the discharge duration longer, thereby changing the air-fuel ratio. Can realize stable combustion.
- flow generation means (2a, 4) for generating a flow of the sucked air-fuel mixture in the combustion chamber.
- the homogeneous lean air-fuel mixture forming means executes the first fuel injection (FI1) by the fuel injection valve (6) during the valve closing period of the intake valve (21) of the engine and the valve opening period of the intake valve. It is desirable to execute the second fuel injection (FI2) by the fuel injection valve.
- the predetermined lean air-fuel ratio (AFL1) is preferably set so that the amount of NOx discharged from the combustion chamber is less than or equal to an allowable upper limit value.
- the predetermined lean air-fuel ratio is set so that the amount of NOx discharged from the combustion chamber is less than or equal to the allowable upper limit value, so that the air-fuel ratio is controlled to an air-fuel ratio range leaner than the predetermined lean air-fuel ratio.
- a three-way catalyst containing platinum is provided in the exhaust passage of the engine, and a first temperature increase promotion control for accelerating the temperature increase of the three-way catalyst (10) immediately after the start of the engine,
- the first temperature increase promotion control means that is executed until the control switching timing (t1) and the second temperature increase promotion control for promoting the temperature increase of the three-way catalyst (10) are executed after the control switching timing (t1).
- Second temperature increase promotion control means for increasing the intake air amount of the engine and setting the air-fuel ratio (AF) of the air-fuel mixture leaner than the stoichiometric air-fuel ratio.
- the first temperature increase promotion control is performed by controlling to 1 lean air-fuel ratio (AFTRA1) and setting the discharge start timing (CAIG) of the spark plug to a predetermined retarded ignition timing (CATRA1) that is retarded from the optimal ignition timing.
- the control means controls the air-fuel ratio (AF) to a second lean air-fuel ratio (AFTRA2) that is leaner than the first lean air-fuel ratio (AFTRA1), and sets the discharge start timing (CAIG) to the predetermined retarded ignition It is desirable to further retard the timing (CATRA1) and increase the discharge duration (TSPK) of the spark plug.
- the first temperature increase promotion control for promoting the temperature increase of the three-way catalyst is executed immediately after the start of the engine until the control switching timing, and after the control switching timing, the temperature increase of the three-way catalyst is accelerated.
- the second temperature increase promotion control is performed for this purpose.
- the intake air amount of the engine is increased, the air-fuel ratio is controlled to the first lean air-fuel ratio leaner than the stoichiometric air-fuel ratio, and the discharge start timing of the spark plug is retarded from the optimal ignition timing.
- the air-fuel ratio is controlled to a second lean air-fuel ratio that is leaner than the first lean air-fuel ratio, and the discharge start timing is delayed by a predetermined delay. Control is performed to further retard the angular ignition timing and increase the discharge duration of the spark plug.
- the three-way catalyst containing platinum is activated at a lower temperature by setting the air-fuel ratio to a leaner side (for example, about “22”) than the set air-fuel ratio (for example, “16”) in the conventional catalyst temperature increase promotion control.
- the activation of the three-way catalyst can be accelerated by performing the second temperature increase promotion control after the control switching time when the temperature of the three-way catalyst becomes higher to some extent. Therefore, the fuel efficiency can be improved by making the air-fuel ratio leaner and shortening the execution time of the catalyst acceleration control.
- a temperature parameter acquisition unit that acquires a catalyst temperature parameter (TCAT) correlated with the temperature (TCAT) of the three-way catalyst is provided, and at the control switching timing (t1), the catalyst temperature parameter (TCAT) is a predetermined temperature ( It is desirable that the time when TCATL) is reached.
- TCAT catalyst temperature parameter
- the control switching time is set to the time when the catalyst temperature parameter reaches the predetermined temperature. Since the second temperature increase promotion control is effective after the time when the temperature of the three-way catalyst reaches the predetermined temperature, the second temperature increase promotion control is executed from the time when the catalyst temperature parameter exceeds the predetermined temperature. As a result, a remarkable temperature increase promoting effect can be obtained.
- the second temperature increase promotion control unit decreases the air-fuel ratio (AF) as the catalyst temperature parameter (TCAT) increases, advances the discharge start timing (CAIG), and discharge duration (TSPK). It is desirable to reduce
- the air-fuel ratio is decreased, the discharge start timing is advanced, and the discharge duration time is decreased. Since the three-way catalyst containing platinum has a characteristic that the purification performance becomes higher as the air-fuel ratio becomes closer to the theoretical air-fuel ratio when the catalyst temperature becomes higher, the higher the catalyst temperature parameter, the lower the air-fuel ratio. Performance can be obtained. In addition, by reducing the air-fuel ratio, stable combustion can be obtained even if the advance angle of the discharge start time and the discharge duration time are shortened. Therefore, the discharge start time is advanced as much as possible and the discharge duration time is reduced. As a result, the engine output can be increased and the energy efficiency can be increased.
- the second temperature increase promotion control means controls the flow intensity of the air-fuel mixture to be relatively high at the start of the second temperature increase promotion control, and sets the air-fuel ratio to the first lean air-fuel ratio (AFTRA1). It is desirable to gradually reduce the strength of the flow from the time (t2) when the flow is reduced to the vicinity.
- the flow strength is controlled to be relatively high, and the flow strength is gradually increased from the time when the air-fuel ratio is reduced to the vicinity of the first lean air-fuel ratio.
- the control to decrease is performed.
- FIG. 1 is a diagram showing the configuration of an internal combustion engine (hereinafter referred to as “engine”) and its control device according to an embodiment of the present invention.
- engine an internal combustion engine
- a throttle valve 3 is placed in the middle of an intake passage 2 of a four-cylinder engine 1. Is arranged.
- a fuel injection valve 6 is provided corresponding to each cylinder, and its operation is controlled by an electronic control unit (hereinafter referred to as "ECU”) 5.
- ECU electronice control unit
- a partition wall 2a and a tumble flow control valve 4 disposed in one flow path formed by the partition wall 2a are provided immediately upstream of the intake valve 21 in the intake passage 2.
- the tumble flow control valve 4 is configured to be opened and closed by an actuator 4a.
- the actuator 4a is connected to the ECU 5, and its operation is controlled by the ECU 5.
- the tumble flow control valve 4 generates a tumble flow of the air-fuel mixture in the combustion chamber 1a.
- a spark plug 8 is attached to each cylinder of the engine 1, and the spark plug 8 is connected to the ECU 5 via the ignition circuit unit 7.
- the ECU 5 controls the discharge start timing CAIG and the discharge duration time TSPK in the spark plug 8 as will be described later.
- the ECU 5 includes an intake air flow sensor 11 that detects the intake air flow rate GAIR of the engine 1, an intake air temperature sensor 12 that detects the intake air temperature TA, a throttle valve opening sensor 13 that detects the throttle valve opening TH, and an intake pressure PBA.
- An intake pressure sensor 14 to detect, a coolant temperature sensor 15 to detect the engine coolant temperature TW, and other sensors (not shown) are connected, and detection signals from these sensors are supplied to the ECU 5.
- the ECU 5 is connected to a crank angle position sensor 16 that detects a rotation angle of a crankshaft (not shown) of the engine 1, and a pulse signal corresponding to the rotation angle of the crankshaft is supplied to the ECU 5.
- the crank angle position sensor 16 outputs a plurality of pulse signals indicating the crank angle position. These pulse signals are used for various timing controls such as fuel injection timing, ignition timing (discharge start timing of the spark plug 8), and the like. Used to detect the engine speed NE.
- the exhaust passage 9 is provided with a three-way catalyst 10 for exhaust purification.
- the three-way catalyst 10 is equipped with a catalyst temperature sensor 18 for detecting the temperature of the three-way catalyst 10 (hereinafter referred to as “catalyst temperature”) TCAT, and the detection signal is supplied to the ECU 5.
- a proportional oxygen concentration sensor 17 (hereinafter referred to as “LAF sensor 17”) is mounted on the upstream side of the three-way catalyst 10 and on the downstream side of the collection portion of the exhaust manifold communicating with each cylinder. 17 outputs a detection signal substantially proportional to the oxygen concentration (air-fuel ratio AF) in the exhaust gas and supplies it to the ECU 5.
- the ECU 5 shapes input signal waveforms from various sensors, corrects the voltage level to a predetermined level, converts an analog signal value into a digital signal value, a central processing unit (CPU), It comprises a storage circuit for storing various calculation programs executed by the CPU and calculation results, an output circuit for supplying a drive signal to the fuel injection valve 6, the ignition circuit unit 7, the actuator 4a, and the like.
- CPU central processing unit
- the fuel injection amount by the fuel injection valve 6 is obtained by correcting the basic fuel amount calculated according to the intake air flow rate GAIR with the air / fuel ratio correction coefficient KAF calculated according to the air / fuel ratio AF detected by the LAF sensor 17. Controlled by.
- the air-fuel ratio correction coefficient KAF is calculated so that the detected air-fuel ratio AF coincides with the target air-fuel ratio AFCMD.
- FIG. 3 is a circuit diagram showing the configuration of the ignition circuit unit 7 corresponding to one cylinder.
- the ignition circuit unit 7 includes a first coil pair 71 including a primary coil 71a and a secondary coil 71b, a primary coil 72a, A second coil pair 72 including a secondary coil 72b, a booster circuit 73 that boosts the output voltage VBAT of the battery 30 and outputs a boosted voltage VUP, transistors Q1 and Q2 that control energization of the primary coils 71a and 72a, Diodes D1 and D2 connected between the secondary coils 71b and 72b and the spark plug 8 are provided.
- the bases of the transistors Q1 and Q2 are connected to the ECU 5, and the ECU 5 performs on / off control (primary coil energization control). It is possible to change the discharge duration (discharge duration) TSPK in the spark plug 8 according to the operating state of the engine 1 by alternately conducting energization while overlapping a part of the energization periods of the two primary coils. it can. Further, the first energization end timing of the primary coil corresponds to the discharge start timing CAIG, and the discharge start timing CAIG can also be changed according to the operating state of the engine 1.
- the fuel injection valve 6 is capable of atomizing and injecting fuel, and has a characteristic of SMD (Sauter Mean Diameter) of about 35 ⁇ m (injection at a fuel pressure of 350 kPa and SMD 50 mm below the injection port). And a valve that can change the opening degree (lift amount) of the valve in at least two stages.
- FIG. 4A schematically shows a fuel injection state (a state in which the injected fuel is diffused) by the fuel injection valve 6, and
- FIG. 4B shows a fuel by a normal fuel injection valve shown for comparison. The injection state of is shown.
- the fuel concentration in the peripheral portion of the fuel distributed in a conical shape is high, whereas in the fuel injection valve 6, the reach of the atomized fuel is shortened and the concentration distribution in the diffusion region is reduced.
- the degree of homogeneity is high (the difference in density is small).
- FIG. 5 is a diagram showing the valve opening timing, the valve opening time TFI, and the lift amount LFT when the fuel injection valve 6 is opened, and the horizontal axis is the crank angle CRA.
- the first fuel injection FI1 is executed in the compression stroke within one combustion cycle
- the second fuel injection FI2 is executed in the intake stroke.
- the first fuel injection FI1 is a fuel injection having a relatively large lift amount LFT1 and a relatively short valve opening time TFI1
- the second fuel injection FI2 has a lift amount LFT2 smaller than the lift amount LFT1 and a valve opening time.
- TFI2 be the fuel injection set longer than the valve opening time TFI1.
- the lift amounts LFT1, LFT2 and the valve opening times (fuel injection times) TFI1, TFI2 are set so that the total fuel injection amount in the first and second fuel injections FI1, FI2 becomes the fuel injection amount corresponding to the target air-fuel ratio AFCMD. Is set.
- a fuel injection valve 6 capable of atomizing and injecting fuel is opened as shown in FIG. 5 to form a relatively homogeneous air-fuel mixture in the intake passage 2 by the first fuel injection FI1,
- an amount of fuel required to make the detected air-fuel ratio AF coincide with the target air-fuel ratio AFCMD is supplied to the combustion chamber, and the air-fuel ratio distribution in the combustion chamber is substantially uniform. It is possible to form a homogeneous (high homogeneity) homogeneous lean mixture.
- first fuel injection FI1 is preferably executed during the compression stroke of the target cylinder
- second fuel injection FI2 is preferably set to have its end timing immediately before the end timing of the intake stroke.
- the target air-fuel ratio AFCMD after the warm-up is completed is set to a range of about “24” to “35” (hereinafter referred to as “ultra-lean air-fuel ratio range”), for example.
- the air-fuel ratio “24” predetermined air-fuel ratio AFL1 is set so that the NOx emission amount (NOx concentration in the exhaust gas) from the engine 1 is equal to or less than the allowable upper limit value CNOxHL (for example, 120 ppm).
- the air / fuel ratio “35” is an air / fuel ratio set as a limit value for obtaining a necessary engine output.
- FIG. 6 is a diagram showing the relationship between the air-fuel ratio AF and the NOx concentration CNOx in the exhaust gas.
- the air-fuel ratio AF is “16” or more, the NOx increases as the air-fuel ratio AF increases (lean).
- the concentration CNOx decreases. Therefore, the predetermined air-fuel ratio AFL1 needs to be set to increase as the allowable upper limit value CNOxHL decreases.
- the discharge start timing CAIG in the spark plug 8 is set to a range of 50 degrees to 15 degrees before top dead center corresponding to the target air-fuel ratio AFCMD in the ultra-lean air-fuel ratio range, and the discharge duration TSPK is a homogeneous lean mixture. In order to ensure ignition, it is set to 1.8 to 3 msec.
- the boost voltage VUP is set so that the discharge energy when the discharge duration time TSPK is set in this way is 150 to 600 mJ.
- Conventional lean mixture combustion by spark ignition is stratified mixture combustion realized by generating a flow in the combustion chamber so that the air-fuel ratio in the vicinity of the spark plug becomes relatively small.
- the discharge start time CAIG is set from the ignition timing (for example, 8.0 degrees) of the stratified mixture combustion so that the discharge duration TSPK is set relatively long and the discharge duration TSPK can be secured. Set to the advance side.
- the geometrical compression ratio of the engine 1 (ratio of the combustion chamber volume when the piston is located at the bottom dead center and the combustion chamber volume when the piston is located at the top dead center) has a minimum effective compression ratio of 9.0. In order to achieve this, it is set slightly larger than the geometric compression ratio of a normal spark ignition engine.
- tumble flow generation control for generating tumble flow with a flow rate of about 5 to 15 m / sec (flow rate when the engine speed NE is 1500 rpm) is performed.
- a strong initial flame kernel is formed, and the flame kernel is grown, so that an unburned mixture at the compression top dead center.
- the elementary reaction that governs the combustion laminar flow rate is changed to a reaction in which hydrogen peroxide decomposes to generate OH radicals, ensuring combustion after compression top dead center Can be completed.
- FIG. 7 is a diagram showing the transition of the in-cylinder pressure PCYL in the compression stroke and the combustion stroke.
- the solid line L1 corresponds to this embodiment
- the thick broken line L2 corresponds to HCCI (homogeneous mixture compression ignition) combustion
- the thin broken line Corresponds to stoichiometric combustion (combustion when the air-fuel ratio is set to the stoichiometric air-fuel ratio).
- the crank angle CRA of 0 degrees corresponds to the compression top dead center.
- the ignition timing in the case of stoichiometric combustion is set slightly ahead of the compression top dead center (for example, a range within a crank angle of 10 degrees). It can be confirmed that highly efficient and stable combustion can be obtained by the combustion of the homogeneous lean air-fuel mixture of the present embodiment by spark ignition.
- the target air-fuel ratio AFCMD is set within the ultra-lean air-fuel ratio range according to the required torque of the engine 1, and the spark plug 8 is discharged according to the target air-fuel ratio AFCMD.
- the start time CAIG and the discharge duration TSPK are set.
- the discharge start timing CAIG (defined by the advance amount from the compression top dead center) is set to advance as the target air-fuel ratio AFCMD increases, as shown in FIG.
- the discharge duration time TSPK is set so as to increase as the target air-fuel ratio AFCMD increases as shown in FIG. 8B.
- AFL1 and AFL2 shown in FIG. 8 are predetermined air-fuel ratios set to, for example, “24” and “35”, respectively.
- CAIG1 and CAIG2 shown in FIG. 8A are, for example, “15 degrees” and “50 degrees, respectively.
- TSPK1 and TSPK2 shown in FIG. 8B are predetermined discharge times set to, for example, “1.8 msec” and “3 msec”, respectively.
- the discharge start timing CAIG is set according to the target air-fuel ratio AFCMD as described above, and advanced as the engine speed NE increases.
- the crank angle CRA corresponding to the discharge duration TSPK increases, so that the required discharge duration TSPK is secured even in a high rotation state by advancing the discharge start timing CAIG and stable. Combustion can be obtained.
- a homogeneous mixture with an ultra lean air / fuel ratio can be formed in the combustion chamber and reliably ignited to complete combustion, so that the homogeneous lean mixture has good controllability. Spark ignition flame propagation combustion can be performed, and combustion with high efficiency and low NOx emission can be realized.
- the fuel atomized by the fuel injection valve 6 is injected into the intake passage 2, a relatively homogeneous lean air-fuel mixture is first formed in the intake passage 2 and further into the combustion chamber 1a. By being inhaled, a lean mixture with higher homogeneity can be formed.
- the discharge start timing CAIG and the discharge duration time TSPK in the spark plug 8 can be controlled, the discharge when the stratified lean air-fuel mixture is ignited by appropriately setting the discharge start timing CAIG and the discharge duration time TSPK. By setting the discharge start time CAIG on the advance side from the start time, the discharge duration time TSPK can be set longer and the homogeneous lean air-fuel mixture can be reliably ignited.
- the discharge start timing CAIG of the spark plug 8 is advanced and the discharge duration time TSPK is set longer. Since the control is performed, stable combustion can be realized corresponding to the change of the target air-fuel ratio AFCMD.
- a powerful initial flame kernel that is, compression top dead center is set by setting the discharge duration TPSK of the spark plug 8 and the air-fuel mixture flow. It is possible to form an initial flame nucleus that can raise the temperature of the combustion mixture at 1000 ° K or higher and realize high-efficiency combustion. That is, in the present embodiment, the air-fuel mixture flow in the combustion chamber is not generated to relatively reduce the air-fuel ratio in the vicinity of the spark plug, but forms a powerful initial flame kernel that completes combustion. Is generated.
- a lean mixture with high homogeneity is formed in the intake passage 2 by the first fuel injection FI1 during the closing period of the intake valve 21, and combustion is performed by performing the second fuel injection FI2 in the subsequent intake valve opening period.
- the chamber 1a it is possible to form a lean air-fuel mixture with a higher degree of homogeneity.
- the predetermined air-fuel ratio AFL1 which is the lower limit value of the ultra-lean air-fuel ratio range, is set so that the amount of NOx discharged from the combustion chamber is less than or equal to the allowable upper limit value, so that the ultra-lean air on the lean side of the predetermined air-fuel ratio AFL1 is set.
- FIG. 9 is a diagram showing the relationship between the air-fuel ratio AF and the activation temperature TACT of the three-way catalyst 10.
- the solid line corresponds to the three-way catalyst 10 containing platinum in the present embodiment, and the broken line is for comparison.
- the relationship between the activation temperature TACT of the three-way catalyst containing palladium and the air-fuel ratio AF is shown.
- the activation temperature TACT is defined as a temperature at which the purification rate (HC purification rate) of hydrocarbon components in the exhaust gas becomes 10%.
- the activation temperature TACT is lowest (activation is accelerated) when the air-fuel ratio AF is in the range of “17” to “18”, but the three-way catalyst containing platinum In the catalyst 10, it can be confirmed that the activation temperature TACT decreases as the air-fuel ratio AF increases. Therefore, in order to activate the three-way catalyst 10 at an early stage, it is effective to perform the temperature rise promotion control with lean air-fuel ratio combustion of the air-fuel ratio “20” to “22”.
- FIG. 10 is a diagram showing the relationship between the temperature of the three-way catalyst 10, that is, the catalyst temperature TCAT, and the HC purification rate ⁇ HC, and the curves L11 to L15 correspond to the air-fuel ratio AF shown in the figure. From this figure, when the catalyst temperature TCAT is about 250 ° C., a high purification rate is obtained when the air-fuel ratio AF is “22.5”, and as the catalyst temperature TCAT rises, the air-fuel ratio AF is decreased to always reduce the air-fuel ratio AF. It can be confirmed that the rate is obtained.
- the air-fuel ratio AF is controlled according to the catalyst temperature TCAT from the time when the catalyst temperature TCAT has risen to some extent (for example, when it has risen to 220 ° C.), thereby The relationship between the catalyst temperature TCAT and the HC purification rate ⁇ HC as indicated by L10 is realized.
- FIG. 11 is a flowchart of the temperature increase promotion control process. This process is executed in the ECU 5 every predetermined time (for example, 10 msec).
- step S11 it is determined whether or not the catalyst temperature TCAT is lower than a predetermined upper temperature TCATH (eg, 350 ° C.). If the answer is negative (NO), that is, if the catalyst temperature TCAT is sufficiently high, the temperature increase promotion control is unnecessary. Therefore, the process is immediately terminated. If the answer to step S11 is affirmative (YES), it is determined whether or not the catalyst temperature TCAT is higher than a predetermined lower temperature TCATL (eg, 220 ° C.) (step S12).
- a predetermined upper temperature TCATH eg, 350 ° C.
- the predetermined lower temperature TCATL corresponds to the lowest temperature at which the above-described temperature increase promotion control by the lean air-fuel ratio combustion (second temperature increase promotion control) is effective.
- step S13 the target opening THCMD of the throttle valve 3 is set to the temperature increase accelerating idle opening THFIDL, and the intake air amount of the engine 1 is increased.
- step S14 the target air-fuel ratio AFCMD is set to a first predetermined air-fuel ratio AFTRA1 (eg, “16”), and in step S15, the discharge start timing CAIG of the spark plug 8 is set to a first predetermined timing that is retarded from the optimal ignition timing.
- CATRA1 for example, 3 degrees
- the discharge duration TSPK is set to a first predetermined time TTRA1 (for example, 2.0 msec (equivalent value of 180 mJ for discharge energy)).
- step S16 the opening command value TCVCMD of the tumble flow control valve 4 is set to a relatively small first predetermined opening TCVTRA1, and the opening is set to correspond to a state where the flow intensity is relatively high.
- the discharge start timing CAIG is defined by the advance amount from the compression top dead center. An increase in the opening command value TCVCMD corresponds to a decrease in the strength of the tumble flow.
- the target opening degree THCMD, the target air-fuel ratio AFCMD, the discharge duration time TSPK, and the opening degree command value TCVCMD are gradually changed from the initial values at the start of the engine 1 to the above set values.
- step S12 When the catalyst temperature TCAT exceeds the predetermined lower temperature TCATL by the first temperature increase promotion control, the answer to step S12 becomes affirmative (YES), and the second temperature increase promotion control by steps S21 to S24 is executed.
- step S21 the AFCMD table shown in FIG. 12A is retrieved according to the catalyst temperature TCAT, and the target air-fuel ratio AFCMD is set.
- the AFCMD table is set to the first predetermined air-fuel ratio AFTRA1 when the catalyst temperature TCAT is lower than the predetermined lower temperature TCATL.
- the target air-fuel ratio AFCMD becomes higher. It is set to decrease.
- the second and third predetermined air-fuel ratios AFTRA2 and AFTRA3 in FIG. 12A are set to “22.5” and “14.7”, for example.
- step S22 the discharge start timing CAIG and the discharge duration time TSPK are set according to the target air-fuel ratio AFCMD. Specifically, the CAIG table shown in FIG. 12B is searched according to the target air-fuel ratio AFCMD, the discharge start timing CAIG is calculated, and the TSPK table shown in FIG. 12C according to the target air-fuel ratio AFCMD. And the discharge duration TSPK is calculated.
- the CAIG table is set so that the discharge start timing CAIG decreases as the target air-fuel ratio AFCMD increases.
- the second and third predetermined times CATRA2 and CATRA3 in FIG. 12B are set to, for example, “0 degree” and “10 degrees”, respectively.
- the second predetermined timing CATRA2 is set to be retarded from the optimal ignition timing and further retarded from the first predetermined timing CATRA1.
- the TSPK table is set so that the discharge duration TSPK increases as the target air-fuel ratio AFCMD increases.
- the second and third predetermined times TTRA2 and TTRA3 in FIG. 12C are set to, for example, “5.0 msec” and “1.5 msec”, respectively.
- step S23 it is determined whether or not the target air-fuel ratio AFCMD is equal to or lower than the first predetermined air-fuel ratio AFTRA1. If this answer is negative (NO), the processing is immediately terminated. If the answer is positive (YES), the opening command value TCVCMD of the tumble flow control valve 4 is changed from the first predetermined opening TCVTRA1 to the second predetermined opening. A process of gradually increasing is performed until TCVTRA2 (> TCVTRA1) is reached (step S24).
- the target air-fuel ratio AFCMD, the discharge start timing CAIG, and the discharge duration time TSPK are calculated in steps S21 and S22 from the set values in the first temperature increase promotion control. Transient control that gradually changes to the first set value is performed.
- FIG. 13 is a time chart showing an operation example of the temperature increase promotion control of FIG. 11, and FIG. 13 (a) shows transitions of the catalyst temperature TCAT and the exhaust gas temperature TEXH from the starting point of the engine 1 (time t0).
- FIGS. 13B to 13E show changes in the air-fuel ratio AF, the discharge duration TSPK, the discharge start timing CAIG, and the opening command value TCVCMD of the tumble flow control valve 4 from time t0, respectively.
- the first temperature increase promotion control is executed immediately after the start, and the air-fuel ratio AF, the discharge duration time TSPK, the discharge start timing CAIG, and the opening command value TCVCMD are respectively the first predetermined air-fuel ratio AFTRA1, the first predetermined time TTRA1, 1 predetermined time CATRA1 and first predetermined opening TCVTRA1 are set.
- the first temperature increase promotion control is shifted to the second temperature increase promotion control.
- transient control that gradually shifts to the first set value is performed, and the air-fuel ratio AF, the discharge duration time TSPK, and the discharge start timing CAIG are respectively set to the second predetermined air-fuel ratio AFTRA2.
- the second predetermined time TTRA2 and the second predetermined time CATRA2 are changed.
- the opening command value TCVCMD is maintained at the first predetermined opening TCVTRA1 until time t2.
- Time t2 is a time point when the target air-fuel ratio AFCMD decreases to the first predetermined air-fuel ratio AFTRA1 (see step S23 in FIG.
- the routine proceeds to normal control for setting the target air-fuel ratio AFCMD according to the engine operating state.
- the first temperature increase promotion control for promoting the temperature increase of the three-way catalyst 10 immediately after the engine 1 is started is executed until the time t1 when the catalyst temperature TCAT reaches the predetermined lower temperature TCATL. Then, after the time t1, the second temperature increase promotion control is executed.
- the intake air amount is increased by increasing the opening degree of the throttle valve 3, the air-fuel ratio AF is controlled to the first predetermined air-fuel ratio AFTRA1 that is leaner than the stoichiometric air-fuel ratio, and the spark plug 8 Is set to a first predetermined timing CATRA1 that is retarded from the optimal ignition timing, and in the second temperature increase promotion control, the air-fuel ratio AF is set further to the lean side than the first predetermined air-fuel ratio AFTRA1. Control is performed to the second predetermined air-fuel ratio AFTRA2, the discharge start timing CAIG is further retarded from the first predetermined timing CATRA1, and the discharge duration time TSPK of the spark plug 8 is increased.
- the three-way catalyst 10 containing platinum has a lower temperature by setting the air-fuel ratio AF to a leaner side (for example, about “22”) than the set air-fuel ratio (for example, “16”) in the conventional catalyst temperature increase promotion control.
- the activation of the three-way catalyst 10 can be accelerated by performing the second temperature increase promotion control after time t1 when the catalyst temperature TCAT reaches the predetermined lower temperature TCATL. Therefore, fuel efficiency can be improved by making the air-fuel ratio AF leaner and shortening the execution time of the catalyst acceleration control.
- the second temperature increase promotion control is effective after the time when the temperature TCAT of the three-way catalyst 10 reaches the predetermined lower temperature TCATL, so that the catalyst temperature TCAT exceeds the predetermined lower temperature TCATL.
- the air-fuel ratio AF is decreased as the catalyst temperature TCAT becomes higher, the discharge start timing CAIG is advanced, and the discharge duration time TSPK is decreased.
- the three-way catalyst 10 containing platinum has a characteristic that when the catalyst temperature TCAT becomes higher, the purification performance becomes higher as the air-fuel ratio AF is closer to the theoretical air-fuel ratio. Therefore, the air-fuel ratio AF (target air-fuel ratio becomes higher as the catalyst temperature TCAT becomes higher. High purification performance can be obtained by reducing (ACMD).
- the opening degree of the tumble flow control valve 4 is set to the first predetermined opening degree TCVTRA1, and the flow intensity is controlled to be relatively high. Control is performed to gradually decrease the strength of the flow from the time when it is reduced to the vicinity of the predetermined air-fuel ratio AFTRA1. By controlling to reduce the air-fuel ratio AF, combustion does not become unstable even if the flow intensity is reduced, so the flow intensity is reduced, heat loss during combustion is reduced, and thermal efficiency is improved. Can do.
- the ignition circuit unit 7 and the spark plug 8 correspond to the spark ignition means
- the partition wall 2a and the tumble flow control valve 4 correspond to the flow generation means.
- the ECU 5 constitutes an ignition control means, an air-fuel ratio control means, a first temperature rise promotion control means, and a second temperature rise promotion control means.
- the fuel injection valve 6 and the ECU 5 constitute a homogeneous lean mixture formation means, and a catalyst.
- the temperature sensor 18 constitutes a temperature parameter acquisition unit.
- the present invention is not limited to the above-described embodiment, and various modifications are possible.
- the detected catalyst temperature TCAT is used as the catalyst temperature parameter.
- the following parameter that is, an exhaust temperature sensor is arranged on the upstream side of the three-way catalyst 10.
- the exhaust temperature TEXH detected by the exhaust temperature sensor may be used as the catalyst temperature parameter.
- the exhaust temperature sensor constitutes a temperature parameter acquisition means.
- an estimated catalyst temperature TCATE may be calculated according to the operating state of the engine 1 using a catalyst temperature estimation method disclosed in Japanese Patent Application Laid-Open No. 2012-77740, and the estimated catalyst temperature TCATE may be used as a catalyst temperature parameter.
- the control switching timing (time t1) at which the first temperature increase promotion control is shifted to the second temperature increase promotion control is set to the time when the catalyst temperature TCAT reaches the predetermined lower temperature TCATL.
- the elapsed time from the cold start start time of the engine 1 reaches the time when the catalyst temperature TCAT is estimated to reach the predetermined lower temperature TCATL, or from the cold start start time.
- the fuel injection amount integrated value reaches a value estimated that the catalyst temperature TCAT reaches the predetermined lower temperature TCATL, that is, the catalyst temperature TCAT is estimated to reach a temperature at which the second temperature increase promotion control is effective.
- the time point may be the “control switching time”.
- a mechanism for generating tumble flow is used as the flow generation means, but a mechanism for generating swirl flow may be employed. Moreover, you may comprise the shape of the combustion chamber 1a and the piston top part so that a squish flow may be produced
- the present invention can be applied regardless of the number of cylinders.
- the present invention can also be applied to a combustion control device such as an engine for a marine propulsion device such as an outboard motor having a vertical crankshaft.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Toxicology (AREA)
- Theoretical Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
Description
しかしこの技術では、点火プラグ近傍における燃焼によって発生するNOx量が多いため、NOx排出量をより低減することが求められている。
図1は、本発明の一実施形態にかかる内燃機関(以下「エンジン」という)及びその制御装置の構成を示す図であり、例えば4気筒のエンジン1の吸気通路2の途中にはスロットル弁3が配置されている。吸気通路2のスロットル弁3の下流側には、燃料噴射弁6が各気筒に対応して設けられており、その作動は電子制御ユニット(以下「ECU」という)5により制御される。
放電継続時間TSPKを比較的長く設定するとともに、燃焼室内にタンブル流動を生成することによって、強力な初期火炎核を形成し、その火炎核を成長させることによって、圧縮上死点における未燃混合気の温度を1000度K以上の温度まで高めて、燃焼層流速度を支配する素反応を、過酸化水素が分解してOHラジカルを生成する反応に変化させ、圧縮上死点後において燃焼を確実に完結させることが可能となる。
本実施形態の均質希薄混合気の火花点火による燃焼によって、高効率の安定した燃焼が得られることが確認できる。
図9は、空燃比AFと、三元触媒10の活性化温度TACTとの関係を示す図であり、実線が本実施形態における白金を含む三元触媒10に対応し、破線は比較のためにパラジウムを含む三元触媒の活性化温度TACTと、空燃比AFとの関係を示す。活性化温度TACTは、排気中の炭化水素成分の浄化率(HC浄化率)が10%となる温度として定義されている。
ステップS11では、触媒温度TCATが所定上側温度TCATH(例えば350℃)より低いか否かを判別し、その答が否定(NO)、すなわち触媒温度TCATが十分高いときは、昇温促進制御は不要であるため直ちに処理を終了する。ステップS11の答が肯定(YES)であるときは、触媒温度TCATが所定下側温度TCATL(例えば220℃)より高いか否かを判別する(ステップS12)。エンジン1の冷間始動直後は、最初はこの答は否定(NO)となり、ステップS13~S16によって第1昇温促進制御を実行する。所定下側温度TCATLは、上述した希薄空燃比燃焼による昇温促進制御(第2昇温促進制御)が有効となる最低温度に相当する。
時刻t3において触媒温度TCATが所定上側温度TCATHに到達し、第2触媒昇温促進制御が終了する。第2昇温促進制御終了後は、エンジン運転状態に応じた目標空燃比AFCMDの設定を行う通常制御に移行する。
2 吸気通路
2a 隔壁(流動生成手段)
4 タンブル流動制御弁(流動生成手段)
5 電子制御ユニット(点火制御手段、空燃比制御手段、均質希薄混合気形成手段、第1及び第2昇温促進制御手段)
6 燃料噴射弁(均質希薄混合気形成手段)
7 点火回路ユニット(火花点火手段)
8 点火プラグ(火花点火手段)
10 三元触媒
18 触媒温度センサ(温度パラメータ取得手段)
19 アクチュエータ
AFCMD 目標空燃比
CAIG 放電開始時期
TSPK 放電継続時間
AFCMD 目標空燃比
Claims (9)
- 内燃機関の燃焼室内の混合気の火花点火を行う火花点火手段と、該火花点火手段を制御する点火制御手段と、前記燃焼室内の混合気の空燃比を制御する空燃比制御手段とを備える、内燃機関の燃焼制御装置であって、
前記燃焼室内に均質かつ希薄な混合気を形成する均質希薄混合気形成手段を備え、
前記火花点火手段は、点火プラグと、該点火プラグに放電を発生させるための複数の点火コイル対とを備え、前記点火プラグにおける放電の開始時期及び継続時間を変更可能なものであり、
前記均質希薄混合気形成手段は、燃料を微粒化して噴射可能な燃料噴射弁を用いて、前記機関の吸気通路内に燃料を噴射し、
前記空燃比制御手段は、前記空燃比を理論空燃比よりリーン側の所定リーン空燃比よりさらにリーン側の空燃比に制御し、
前記点火制御手段は、前記点火プラグにおける放電開始時期及び前記放電継続時間を制御し、前記放電開始時期を、前記点火プラグ近傍における混合気の空燃比が相対的に小さくなるように形成される成層希薄混合気に点火する場合の放電開始時期より進角側に設定することを特徴とする燃焼制御装置。 - 前記点火制御手段は、前記所定リーン空燃比よりリーン側の空燃比範囲において、前記空燃比が増加するほど、前記放電開始時期を進角させるとともに前記放電継続時間を長く設定する請求項1の燃焼制御装置。
- 前記燃焼室内に吸入された混合気の流動を生成する流動生成手段をさらに備える請求項1または2の燃焼制御装置。
- 前記均質希薄混合気形成手段は、前記機関の吸気弁の閉弁期間において前記燃料噴射弁による第1燃料噴射を実行するとともに、前記吸気弁の開弁期間において前記燃料噴射弁による第2燃料噴射を実行する請求項1から3の何れか1項の燃焼制御装置。
- 前記所定リーン空燃比は、前記燃焼室から排出されるNOx量が許容上限値以下となるように設定される請求項1から4の何れか1項の燃焼制御装置。
- 前記機関の排気通路には、白金を含む三元触媒が設けられており、
前記機関の始動直後において前記三元触媒の昇温を促進するための第1昇温促進制御を、制御切換時期まで実行する第1昇温促進制御手段と、
前記三元触媒の昇温を促進するための第2昇温促進制御を、前記制御切換時期後に実行する第2昇温促進制御手段とをさらに備え、
前記第1昇温促進制御手段は、前記機関の吸入空気量を増加させ、前記混合気の空燃比を理論空燃比よりリーン側の第1リーン空燃比に制御するとともに前記点火プラグの放電開始時期を最適点火時期より遅角側の所定遅角点火時期に設定することによって前記第1昇温促進制御を実行し、
前記第2昇温促進制御手段は、前記空燃比を前記第1リーン空燃比よりさらにリーン側の第2リーン空燃比に制御し、前記放電開始時期を前記所定遅角点火時期よりさらに遅角するとともに、前記点火プラグの放電継続時間を増加させる請求項1の燃焼制御装置。 - 前記三元触媒の温度と相関のある触媒温度パラメータを取得する温度パラメータ取得手段を備え、
前記制御切換時期は、前記触媒温度パラメータが所定温度に達する時期である請求項6の燃焼制御装置。 - 前記第2昇温促進制御手段は、前記触媒温度パラメータが高くなるほど前記空燃比を減少させ、前記放電開始時期を進角させるとともに前記放電継続時間を減少させる請求項6または7の燃焼制御装置。
- 前記燃焼室内に吸入された混合気の流動を生成する流動生成手段をさらに備え、
前記第2昇温促進制御手段は、前記第2昇温促進制御の開始時は、前記流動の強度を比較的高く制御し、前記空燃比を前記第1リーン空燃比近傍まで減少させた時点から前記流動の強度を徐々に低下させる請求項6から8の何れか1項の燃焼制御装置。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201580000310.6A CN105102797B (zh) | 2014-03-10 | 2015-01-30 | 内燃机的燃烧控制装置 |
DE112015000119.0T DE112015000119T5 (de) | 2014-03-10 | 2015-01-30 | Verbrennungssteuervorrichtung für Verbrennungsmotor |
US14/897,884 US9932916B2 (en) | 2014-03-10 | 2015-01-30 | Combustion control apparatus for internal combustion engine |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014-046308 | 2014-03-10 | ||
JP2014046310 | 2014-03-10 | ||
JP2014-046310 | 2014-03-10 | ||
JP2014046308A JP6084941B2 (ja) | 2014-03-10 | 2014-03-10 | 内燃機関の燃焼制御装置 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2015137003A1 true WO2015137003A1 (ja) | 2015-09-17 |
Family
ID=54071457
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2015/052676 WO2015137003A1 (ja) | 2014-03-10 | 2015-01-30 | 内燃機関の燃焼制御装置 |
Country Status (4)
Country | Link |
---|---|
US (1) | US9932916B2 (ja) |
CN (1) | CN105102797B (ja) |
DE (1) | DE112015000119T5 (ja) |
WO (1) | WO2015137003A1 (ja) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6520189B2 (ja) | 2014-04-10 | 2019-05-29 | 株式会社デンソー | 点火装置 |
JP6260795B2 (ja) * | 2015-03-27 | 2018-01-17 | マツダ株式会社 | エンジンの燃料制御装置 |
JP6319170B2 (ja) * | 2015-04-30 | 2018-05-09 | トヨタ自動車株式会社 | 多気筒エンジン |
JP6854581B2 (ja) * | 2015-07-07 | 2021-04-07 | 日立Astemo株式会社 | 内燃機関の制御装置 |
JP6332345B2 (ja) | 2016-07-05 | 2018-05-30 | トヨタ自動車株式会社 | 内燃機関の制御装置 |
DE102017107678A1 (de) | 2017-04-10 | 2018-10-11 | Volkswagen Aktiengesellschaft | Verfahren zur Inbetriebnahme eines Verbrennungsmotors und Kraftfahrzeug mit einem Verbrennungsmotor |
DE102017206301B3 (de) * | 2017-04-12 | 2018-06-14 | Continental Automotive Gmbh | Verfahren und Vorrichtung zum Starten einer Brennkraftmaschine mit hohem Alkoholanteil im Kraftstoff |
EP3633182A4 (en) | 2017-05-24 | 2020-06-17 | Nissan Motor Co., Ltd | COMBUSTION ENGINE CONTROL METHOD AND CONTROL DEVICE |
US11248555B2 (en) | 2017-05-24 | 2022-02-15 | Nissan Motor Co., Ltd. | Control method and control device for internal combustion engine |
US10233891B1 (en) | 2017-10-23 | 2019-03-19 | Caterpillar Inc. | Controller for spark plug of engine |
JP7052535B2 (ja) * | 2018-05-02 | 2022-04-12 | マツダ株式会社 | 圧縮着火式エンジンの制御装置 |
JP2020070770A (ja) * | 2018-11-01 | 2020-05-07 | マツダ株式会社 | エンジンの制御装置 |
JP7052748B2 (ja) * | 2019-01-29 | 2022-04-12 | トヨタ自動車株式会社 | 車両の制御装置 |
US11624333B2 (en) | 2021-04-20 | 2023-04-11 | Kohler Co. | Exhaust safety system for an engine |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6238853A (ja) * | 1985-08-14 | 1987-02-19 | Hitachi Ltd | 空燃比制御方法 |
JP2000045844A (ja) * | 1998-08-03 | 2000-02-15 | Mazda Motor Corp | 筒内噴射式エンジンの制御装置 |
JP2002295287A (ja) * | 2001-03-30 | 2002-10-09 | Mazda Motor Corp | ターボ過給機付火花点火式直噴エンジン |
JP2005030305A (ja) * | 2003-07-14 | 2005-02-03 | Toyota Motor Corp | 希薄燃焼内燃機関及び希薄燃焼内燃機関の混合気形成方法 |
JP2009108760A (ja) * | 2007-10-30 | 2009-05-21 | Mitsubishi Electric Corp | 内燃機関の燃焼状態検出装置及び燃焼状態検出方法 |
JP2011001905A (ja) * | 2009-06-19 | 2011-01-06 | Nissan Motor Co Ltd | 可変圧縮比式内燃機関 |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4103653A (en) * | 1975-11-28 | 1978-08-01 | Nissan Motor Company, Limited | Method of and apparatus for controlling ignition timing of an internal combustion engine |
US5211147A (en) * | 1991-04-15 | 1993-05-18 | Ward Michael A V | Reverse stratified, ignition controlled, emissions best timing lean burn engine |
JP2964298B2 (ja) * | 1994-04-07 | 1999-10-18 | 三菱自動車工業株式会社 | 空燃比制御方法 |
KR0150432B1 (ko) * | 1994-05-10 | 1998-10-01 | 나까무라 유이찌 | 내연엔진의 제어장치 및 제어방법 |
EP1192354B1 (en) * | 1999-06-16 | 2006-08-16 | Knite, Inc. | Dual-mode ignition system utilizing traveling spark ignitor |
JP2002256927A (ja) | 2001-03-02 | 2002-09-11 | Toyota Motor Corp | 内燃機関の制御装置 |
US7472687B2 (en) * | 2002-11-01 | 2009-01-06 | Visteon Global Technologies, Inc. | System and method for pre-processing ionization signal to include enhanced knock information |
US7690352B2 (en) * | 2002-11-01 | 2010-04-06 | Visteon Global Technologies, Inc. | System and method of selecting data content of ionization signal |
JP2012077740A (ja) | 2010-09-08 | 2012-04-19 | Toyota Motor Corp | 内燃機関の燃料噴射量制御装置 |
JP5533732B2 (ja) * | 2011-02-24 | 2014-06-25 | マツダ株式会社 | 火花点火式ガソリンエンジンの制御装置 |
JP6020600B2 (ja) * | 2013-01-16 | 2016-11-02 | マツダ株式会社 | 火花点火式エンジンの触媒早期暖機制御装置 |
-
2015
- 2015-01-30 CN CN201580000310.6A patent/CN105102797B/zh active Active
- 2015-01-30 DE DE112015000119.0T patent/DE112015000119T5/de not_active Withdrawn
- 2015-01-30 WO PCT/JP2015/052676 patent/WO2015137003A1/ja active Application Filing
- 2015-01-30 US US14/897,884 patent/US9932916B2/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6238853A (ja) * | 1985-08-14 | 1987-02-19 | Hitachi Ltd | 空燃比制御方法 |
JP2000045844A (ja) * | 1998-08-03 | 2000-02-15 | Mazda Motor Corp | 筒内噴射式エンジンの制御装置 |
JP2002295287A (ja) * | 2001-03-30 | 2002-10-09 | Mazda Motor Corp | ターボ過給機付火花点火式直噴エンジン |
JP2005030305A (ja) * | 2003-07-14 | 2005-02-03 | Toyota Motor Corp | 希薄燃焼内燃機関及び希薄燃焼内燃機関の混合気形成方法 |
JP2009108760A (ja) * | 2007-10-30 | 2009-05-21 | Mitsubishi Electric Corp | 内燃機関の燃焼状態検出装置及び燃焼状態検出方法 |
JP2011001905A (ja) * | 2009-06-19 | 2011-01-06 | Nissan Motor Co Ltd | 可変圧縮比式内燃機関 |
Also Published As
Publication number | Publication date |
---|---|
DE112015000119T5 (de) | 2016-04-21 |
US9932916B2 (en) | 2018-04-03 |
US20160115880A1 (en) | 2016-04-28 |
CN105102797B (zh) | 2017-11-14 |
CN105102797A (zh) | 2015-11-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2015137003A1 (ja) | 内燃機関の燃焼制御装置 | |
JP6170852B2 (ja) | 内燃機関の燃焼制御装置 | |
JP4023115B2 (ja) | 直噴火花点火式エンジンの制御装置 | |
JP4793381B2 (ja) | 内燃機関の燃料噴射制御装置 | |
US8936007B2 (en) | Fuel injection control apparatus of internal combustion engine | |
JP6183295B2 (ja) | 内燃機関の制御装置 | |
JP2017186984A (ja) | 内燃機関の制御装置 | |
KR19980033086A (ko) | 기통내분사형 내연엔진의 배기승온장치 | |
JP2009275654A (ja) | 内燃機関の燃料噴射制御装置 | |
JP2009293595A (ja) | 内燃機関の燃料噴射制御装置 | |
JP6141801B2 (ja) | 内燃機関の制御装置 | |
JP6010642B2 (ja) | 内燃機関の燃焼制御装置 | |
JP6252647B1 (ja) | 予混合圧縮着火式エンジンの制御装置 | |
JP5079754B2 (ja) | 内燃機関の制御装置 | |
JP2009299490A (ja) | 内燃機関の燃料噴射制御装置 | |
JP2018040264A (ja) | 内燃機関の制御装置 | |
JP6549551B2 (ja) | 内燃機関の制御装置 | |
JP6195545B2 (ja) | 内燃機関の制御装置 | |
JP2015175249A (ja) | 内燃機関の燃焼制御装置 | |
JP2006112329A (ja) | 筒内直接噴射式火花点火内燃機関の制御装置 | |
JPH10212995A (ja) | 排気昇温装置 | |
JP2004028031A (ja) | 直噴火花点火式エンジンの制御装置及び制御方法 | |
JP6084941B2 (ja) | 内燃機関の燃焼制御装置 | |
JP6142662B2 (ja) | エンジン用触媒の暖機装置及び暖機方法 | |
JP2011236802A (ja) | 内燃機関の制御装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201580000310.6 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 15760847 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14897884 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 112015000119 Country of ref document: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 15760847 Country of ref document: EP Kind code of ref document: A1 |